ognizant Communication Corporation


VOLUME 7, NUMBER 1 (Abs 1-62), 2000

Life Support & Biosphere Science, Vol. 7, pp. 23-83, 2000
1069-9422/00 $20.00 + .00
Copyright © 2000 Cognizant Comm. Corp.
Printed in the USA. All rights reserved.

Note: Volume 7, Number 1 is a special abstract issue from the 4th International Conference on Life Support and Biosphere Science held in Baltimore, Maryland, August 6-9, 2000. Abstracts were presented in the following areas:

AEMC 1, Page 23

Microgravity Compatible Reagentless Instrumentation for Detection of Dissolved Organic Acids and Alcohols in Potable Water

James R. Akse, Ph. D., John Holtsnider, and Ray Wheeler

Umpqua Research Company
P.O. Box 609, Myrtle Creek, Oregon 97457, USA
(541) 863-7770

The trace organic content of reclaimed water during long duration manned missions is an important parameter which must be monitored to ensure crew health and to diagnose potential problems within the primary water processor. Organic acids and alcohols are common contaminants that occur in humidity condensate, urine distillate, and composite wastewaters which must be removed by the water processor. In current physico-chemical water recovery systems, organic acids are removed by the ion exchange section of the multifiltration (MF) sorption media. Organic acids are also produced by the catalytic oxidation of dissolved alcohols not removed by MF in the Volatile Removal Apparatus (VRA). These organic acids are then removed by post-treatment ion exchange. Since low molecular weight organic acids and alcohols represent a significant and varying fraction of organic contaminants at different process points within the water treatment system, assessment of water processor performance and diagnosis of malfunctions can be improved upon significantly by the addition of alcohol and organic acid analytical capability. The detection of organic acids is based upon sample acidification using 'reagentless' Solid Phase Acidification (SPA) media in a flow through bed. Following acidification, the chief interferant, CO2, is removed by selective membrane degassing. Under acidic conditions, organic acids become volatile and are subsequently transferred across a selective membrane into a deionized water stream. Once in the analytical stream, organic acids are first segregated and then quantitated based upon the specific conductance response. For alcohol detection, the sample initially flows through a catalytic bed where alcohols are converted to the corresponding organic acid. Each unit process in this analytical sequence will be detailed, and the performance capabilities for detection of the predominant organic acids and alcohols found in current water recovery systems described. Finally, the relative ease with which these analytical unit processes can be extended to other significant contaminants will be discussed.

AEMC 2, Page 24

Evaluation of Fieldbus and OPC for Advanced Life Support

Richard P. Boulanger

Sverdrup Technology

FoundationT Fieldbus and OPCT (OLET for Process Control) technologies were integrated into an existing control system for a crop growth chamber at NASA Ames Research Center. FoundationT Fieldbus is a digital, bi-directional, multi-drop, serial communications network which functions essentially as a LAN for sensors. FoundationT Fieldbus is heterarchical, with publishers and subscribers of data performing complex control functions at low levels without centralized control and its associated overhead. OPCT is a set of interfaces which replace proprietary drivers with a transparent means of exchanging data between the fieldbus and applications.

The objectives were:
1. to integrate FoundationT Fieldbus into existing ALS hardware and determine its overall effectiveness and reliability and,
2. to quantify any savings produced by using fieldbus and OPC technologies.

We encountered several problems with the FoundationT Fieldbus hardware chosen. Our hardware exposed 100 data for each channel of the fieldbus. The fieldbus configurator software used to program the fieldbus was simply not adequate. The fieldbus was also not inherently reliable. It lost its settings twice during our tests for unknown reasons.

OPC also had issues. It did not function at all as supplied, requiring substitution of some of its components with those from other vendor. It would stop working after a fixed period of time. Certain database calls eventually lock the machine.

Overall, we would not recommend FoundationT Fieldbus: it was too difficult to implement with little overall added value. It also seems unlikely that FoundationT Fieldbus will gain sufficient penetration into the laboratory instrument market to ever be cost effective for the ALS community.

OPC had good reliability and performance once a stable installation was achieved. It allowed a rapid change to an alternative software strategy when our first strategy failed. It is a cost effective solution to distributed control systems development.

AEMC 4, Page 25

Advanced Techniques for Automated Control and Monitor of Bioregenerative Life Support Environments

William Little


Improvements in computer hardware and software technology have made it possible to implement advanced computing techniques for real-time monitor and control of plant growth environments and their accompanying engineering support systems. The combination of powerful and flexible yet architecturally simple hardware platforms with commercially available software packages has yielded the Advanced Life Support (ALS) Advanced Control Technology (ALSACT) Project control system at the NASA Kennedy Space Center Life Sciences Support Facility (LSSF). ALSACT has been designed to be intelligent, flexible, configurable, and user friendly. ALSACT's use of rule based, object oriented strategies coupled with advanced decision-making processes, such as fuzzy logic, has produced significant improvements in automated, "hands off" control capabilities. ALSACT also maintains a graphical user interface (GUI) that allows an operator to modify in real time environmental system setpoints, support engineering equipment operations, and software functions to modify overall system performance as desired and correct for subsystem failures and breakdowns.

Initial applications of ALSACT in the LSSF controlled environment chamber 16 (CEC-16) have demonstrated the flexibility and reliability of the system. As a development platform, ALSACT has proven to be quite powerful. Updates to software functions and user interfaces can be made "on the fly" to meet user requirements without the necessity to stop, recompile, and restart application software. Operationally, ALSACT's capabilities to handle the tasks of maintaining system health and reporting anomalous conditions have proven helpful to engineering and scientific team members by allowing them to concentrate on other, higher priority duties. Their direct involvement with the system is required to modify the system, and they are freed from "babysitting" duties when the system is performing nominally. As a support tool for plant growth experiments, ALSACT has been instrumental in providing a stable, reliable environment which has allowed ALS researchers to carry out plant growth with increased fidelity, resulting in improved crop production technology. This system may have significant impact on both space-based and terrestrial life support applications.

AEMC 5, Page 26

A New Technique for Long-Term monitoring of Airborne Contaminants

Dr D E Slavin and Dr DiNardi

UMASS-Amherst, ODU and Assay Technology

Objective: To describe a long term passive monitor to measure trace concentrations of airborne contaminants and a rating system to prioritize chemicals for entry into a monitoring protocol.

Background: Life in closed environments, such as a submarine, represents a unique occupational and environmental exposure to trace air contaminants. These contaminants are usually generated through material off gassing, human metabolism, and operation of machinery or activities such as cooking and finally through chemical reactions of parent compounds in machines (e.g. electrostatic precipitators).

Methodology: To select contaminants for monitoring, NSMRL has developed a unique rating system to aid decision making in a robust and auditable way, so that appropriate air sampling technology (active, grab, real-time, and passive) may be developed. Active air sampling has many disadvantages including labor-intensive calibration, operation and maintenance. The sampling equipment is expensive, requiring space and power. The advantages are that they are the reference analytical methods for National Institute for Occupational Safety and Health (NIOSH), Occupational Safety and Health Administration (OSHA) and the Environmental Protection Agency (EPA). Passive sampling devices minimize the disadvantages of active sampling, while building on the strengths of the NIOSH, OSHA, and EPA methodologies. Passive sampling's advantages are simplicity, ease of calibration and maintenance, cost, power consumption and space. Disadvantages are that they are susceptible to environmental parameters of air motion, reverse diffusion of chemicals and they do not give a real time output. Passive sampling monitors are being used more frequently as personal dosimeters for the 8-hour working day but have never been considered as "long-term" (greater than 12 hours) integrating monitors.

NSMRL has developed an in vivo validation program to establish that the passive monitor can be a reliable long-term airborne contaminant monitor. The null hypothesis is that there is no statistically significant difference between the collection efficiency of passive air sampling monitors compared to active air samples collected in accordance with accepted reference methods when sampling for formaldehyde, acrolein and ozone. This program is in parallel with in vitro laboratory permeation validation and manufacturer sponsored quality assurance testing programs.

BLSS 6, Page 27

Mars Base Zero

Ray R. Collins, President

P.O. Box 60885
Fairbanks, Alaska 99706-0885
(907) 488-1001 (office) or 479-7320 (Mars Base Zero)
E-mail: fsrrc@aurora.alaska.edu
ISECCo web site: http://sedona.phys.uaf.edu/~isecco/

Mars Base Zero is a semi-closed ecosystem designed to research food production for space applications. Occupied and operational since October 1st, 1999, our ecosystem is slowly coming alive. While we do not expect to be able to support a person on our limited growing area (80 square meters), we expect to produce a third of the calories needed and most of the food weight needed for one person. The research goal of Mars Base Zero is determining the area needed to sustain a person using our techniques. We shall also learn how to recycle wastes produced in our ecosystem, how to deal with gasses like ethylene, the most efficient way to recycle nutrients like water, nitrogen, potassium, etc. We will investigate the effects of supplemental lighting, CO2 enrichment, the efficiencies of using vertebrate and invertebrate protein sources, and the difficulties of operating a closed ecosystem/greenhouse in the extreme Fairbanks environment. Unfortunately sealed operation is not possible, for our structure cannot withstand changing barometric pressures. Our ecosystem is in the process of being built. With the unfinished construction we need to proceed slowly or the needs of the ecosystem will exceed our ability to support it. Even after problems like uneven heating have been overcome, it will take time, for compost piles need cure, earthworm populations are not yet established, crop rotations and planting cycles need to be determined and experimented with. By the time of the conference more data will be available. Mars Base Zero is a project undertaken by the International Space Exploration and Colonization Company. Ray R. Collins is the lead scientist and primary author.

BLSS 7, Page 28

Mechanical Stimulation of Tomato Stem Increases Yield in a Fixed-Height Production System

Thomas J. Gianfagna, Logan Logendra and Harry W. Janes

Plant Science Department
Rutgers University
59 Dudley Road
New Brunswick, NJ 08901-8520
Tel: 732-932-9711 x252
Fax: 732-932-9441
E-mail: gianfagna@aesop.rutgers.edu

 Crop production in the ALS Systems Integrated Test Bed (ALSSITB), and on future lunar and planetary stations, will be constrained by physical space, energy supply, and labor availability. Methods must be developed to increase crop productivity so that a sustainable supply of food can be grown with the limited resources that can be allocated for this purpose. Crop productivity is usually measured by computing the harvest index (HI), the ratio of fruit or grain yield to total growth above ground. For the ALSSITB, an additional parameter for determining crop production efficiency will be yield/volume since physical space for crop growth will be limited in 3 dimensions. Our previous research has demonstrated that internode elongation is a suitable target for reducing plant height and increasing HI. Plant stems are thigmotropic. Mechanical stimulation of the plant stem will reduce internode elongation and can be used as a simple non-chemical method for height control.

 Tomato (cv. Laura) plant stems were vibrated daily for 30 s, 21-42 d after sowing. Untreated plants were topped after producing two leaves above a single cluster of fruit. This occurred at a height of 84.5 cm. Mechanically stimulated plants were grown to a similar height and then topped. Internode length was significantly reduced on mechanically stimulated plants. The height to the first cluster was 33.8 cm compared to 70.6 cm for untreated plants. Mechanically stimulated plants produced 2.9 fruiting clusters with a yield of 1.87 kg fruit/plant compared to 0.96 kg fruit/plant for the single cluster control plants in a similar volume of growing space.

 Plant height is inversely related to light intensity. For fixed-height production systems, substantial savings in energy use can be obtained by growing plants at low intensities with mechanical stimulation during the first 35 days of crop production.

BLSS 8, Page 29

Controlling Root Growth of Radish Plants in an Aeroponic System

M. Lefsrud1, G. Giacomelli, and H. Janes

1Rutgers, The State University of New Jersey
Bioresource Engineering
20 Ag Extension Way
New Brunswick, NJ 08901
Tel: 732 932 9753
Fax: 732 932 7931
E-mail: lefsrud@bioresource.rutgers.edu

In plant production systems considerable root growth is required for healthy plants.  In systems where space and weight are limited, excessive root growth has a negative effect on the overall efficiency of the system.  The negative effects of excess root growth are increased energy expenditure and nutrients to grow the roots, reduced edible biomass ratio and energy and space requirements.  Root production is necessary in biological life support systems, but by varying the watering frequency of radish plants in an aeroponic system the total length of roots can be controlled.  At higher watering frequencies longer roots are produced, while at low watering frequency shorter roots are produced.  The root length could be controlled without affecting the total mass of the roots or the total biomass produced by the plant. The primary advantage of less frequent watering is reduced energy usage. Watering once every 3 hours for 5 minutes as opposed to watering for 5 minutes every 10 minutes results in a 94% reduction in energy consumption.

BLSS 9, Page 30

Leaf Removal of Romaine Lettuce for Continuous Harvest within the Salad Machine

M. Lefsrud1, G. Giacomelli, H. Janes, and E. Stiles

1Rutgers, The State University of New Jersey
Bioresource Engineering
20 Ag Extension Way
New Brunswick, NJ 08901
Tel: 732 932 9753
Fax: 732 932 7931
E-mail: lefsrud@bioresource.rutgers.edu

In conventional plant production systems plants are allowed to grow to maturity before harvest occurs. In a limited growing space this cause feast and famish cycles that have to be balanced with increased storage. Allowing harvest to occur over the life span of the plant limits the storage requirements. Harvesting lettuce leaves before the plant has reached maturity allows for more uniform lettuce production. When leaves are removed from the outside of the lettuce plant in small amounts over a long period of time the total biomass that is produced by the plant is not affected. Removing 1 or 2 leaves every week from the lettuce plant does not have a significant effect on the health of the plant. This would allow for continuous harvest of lettuce inside a salad machine without having to wait for the lettuce head to reach maturity.

BLSS 10, Page 31

Seed Planting and Germination Protocols for Microgravity Applications

Howard G. Levine1 and Kristie Louie2

1Dynamac Corporation, Life Sciences Support Facility, Kennedy Space Center, FL 32899
2Department of Microbiology, University of California at Davis, Davis CA 95616

1Gravitational Biology Laboratory
Life Sciences Support Facility
Mail Code DYN-3
Kennedy Space Center, FL 32899
Tel: 321-476-4321
Fax: 321-853-4220
E-mail:  Howard.Levine-1@ksc.nasa.gov

For operation on the International Space Station, most plant-based investigations will involve plant growth hardware that will be launched in an unpowered, dry condition and initiated by the crew on-orbit. This raises a number of operational challenges in terms of seed handling protocols. Similar challenges will be faced in future space-based Bioregenerative Life Support Systems which will require the repeated planting and harvesting of plants under microgravity conditions. We have developed a seed handling method, suitable for both porous tube and substrate-based nutrient delivery systems (NDS'), that facilitates these operations. Based upon an experimental assessment of capillary wicking capacities, candidate materials were selected for use as a water input tube wrap onto which seeds were attached using guar glue. The mat-seed unit was then fastened around the water input tubes using either snap fixtures or VelcroT . Alternative design configurations were developed and assessed in germination trials with both the Yecora rojo and Apogee strains of wheat (Triticum aestivum). The developed designs facilitated high rates of germination (> 90%) and ease of handling for both porous tube and substrate-based NDS' designed to grow plants in space. The ability to initially imbibe, in a uniform fashion, plant seeds under microgravity conditions will be a critical operational requirement for all long-duration plant growth efforts in space. The methodologies presented here provide a starting point for accomplishing these objectives.

BLSS 11, Page 32

Improving Tomato Crop Yield for Fixed-Height Production Systems

Logan Logendra, Thomas J. Gianfagna and Harry W. Janes

Plant Science Department
Rutgers University
59 Dudley Road
New Brunswick, NJ
Tel: 732-932-9711 x252
Fax: 732-932-9441
E-mail: gianfagna@aesop.rutgers.edu

Crop production in the modules designed for lunar and planetary space stations will be limited by vertical height restrictions, labor availability and energy allocation for crop lighting. As a result, the production system must be designed to maximize crop yield/volume of growing space, with minimum labor requirements and maximum conversion efficiency of light energy into the harvestable crop. Plant architecture and spacing are important components in the design of an efficient production system. Leaves above the final cluster increase plant height, but may contribute significantly to crop yield. Under 2 light levels, yield was significantly greater with 2 leaves above a single fruiting cluster than with 0 or 1 leaf. When 1 or 2 clusters were compared under moderate light levels (12 moles/m2/d), yield was 30% greater for the 2-cluster system, and crop production time was not significantly increased. Adding a third cluster at moderate light levels did not result in a significant increase in yield, moreover, crop height and production time were greater. For 2 typical spacing designs (30x30 versus 30x60 cm), the wider spacing resulted in an increase in yield at high light intensities (17 moles/m2/d), and comparable yield at lower light levels (7 moles/m2/d), with reduced labor requirements compared to the 30x30 cm spacing. For the high quality, indeterminate variety 'Laura', a 2-cluster system with 2 leaves above the second cluster at 30x60 cm spacing was the best of the designs tested.

BLSS 12, Page 33

Spaceflight Results from an Experimental Closed Life Support System

Taber K. MacCallum1 , Grant A. Anderson1 , Jane E. Poynterl, Yoji Ishikawa2, Kensei Kobayashi3, Kotaro Seki3, Hiroshi Mizutani4, Yukishige Kawasaki5, Junpei Koike6, Kenichi Ijiri7 , Masamichi Yamashita8, Katsura Sugiura9, Louis S. Stodiecklo10, and David M. Klauslo10

1 Paragon Space Development Corporation, Tucson,
810 E. 47th St. Ste 104
Tucson, AZ 85713 USA
Tel: 520 903 1000 ext. 15 or 800 TO-ORBIT (866 7248) ext. 15
Mobile: 5203703322
Fax: 520 903 2000
2Obayashi Corporation, Kiyose, Tokyo, 204-0011, Japan
3 Yokohama National University, Hodogaya-ku, Yokohama, 240, Japan
4 Nihon University, Kameino, Fujisawa, 252-8510, Japan
5 Mitsubishi Kasei Institute of Life Sciences, Minami-Ohya, Machida, 194, Japan
6 Tokyo Institute of Technology, Nagatsuta, Yokohama, 226, Japan
7 University of Tokyo, Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
8 Institute of Space and Astronautical Science, Sagamihara, Kanagawa 229-8510, Japan
9 Sagami Women's University, Sagamihara, Japan
10 BioServe Space Technologies, Bolder, Colorado, USA

Three space flight experiments have been conducted to test and demonstrate the use of a passively controlled, materially closed, bioregenerative life support system in space. The Autonomous Biological System (ABS) provides for long term growth and breeding of aquatic plants and animals, within complete material closure, isolated from the spacecraft life support system and cabin atmosphere contaminants, and with little need for astronaut intervention. The ABS may be considered a closed ecological system. Testing of the ABS marked several firsts: the first aquatic angiosperms to be grown in space; the first higher organism (aquatic invertebrate animals) to complete its life cycle in space; the first completely bioregenerative life support system in space; and, among the first gravitational ecology experiments. In May, 1996, two ABS flew on STS 77, followed by two four month stays onboard the Russian Space Station Mir during STS-79/81 (September 1996 to January 1997) and STS-86/89 (September 1997 to January 1998). This paper describes the ABS, its flight performance, advantages and disadvantages. Results from animal behavior studies using in flight video on Mir are presented along with data comparing the flight and ground control systems water chemistry, microorganism and plants.

BLSS 13, Page 34

Moisture Control in Microgravity-Rated Nutrient Delivery Systems

O. Monje and G.W. Stutte

Dynamac Corp.
Kennedy Space Center, FL 32899

O. Monje
Tel: 321-476-4326
Fax: 321-8534220

Substrate-based nutrient delivery systems (NDS) are well-suited for microgravity-rated, plant growth systems because they avoid the fluid handling problems associated with hydroponics. However, active control of substrate moisture is essential for cultivating crops in Advanced Life support Systems because plant growth rate and health are decreased by excessive watering (waterlogging) or drought. Precise moisture control is also needed because these systems are characterized by shallow root zones and by rapidly transpiring plants. We compared and evaluated various candidate moisture sensors for reliability and accuracy of control. Heat-pulse moisture sensors were the most suitable sensors for controlling root zone moisture. We grew a wheat crop for 24 days, whereby water was added or removed from the substrate through a porous tube using peristaltic pumps. Moisture content in the substrate could be maintained within ±2% of setpoint for moisture contents ranging from 40% to 100% volumetric moisture content.

BLSS 14, Page 35

Small Is Better: The Advantages of Super-Dwarf Crop Plants in ALS Research

Bruce Bugbee

Crop Physiology Laboratory
Utah State University, Logan, UT

Extremely dwarf genotypes of most of our major crop plants exist, but they have not been utilized for ALS research. When these plants are less than about 20 cm tall at maturity we have called them super-dwarf cultivars. Their yield in field studies is only about 25% of their tall counterparts; however, their yield increases to about 50% of taller cultivars when grown at high plant densities in near-optimal controlled environments. When yield is expressed on a unit volume basis, these cultivars often exceed all other genotypes. Multiple plants can be grown in small plots in small plant growth chambers. In some cases, the size of a plant growth chamber can be reduced to a 30 x 30 cm plot area, 30 cm tall. This size means that multiple small chambers can be accommodated in a larger plant growth chamber, thus facilitating replicate chambers of environmental treatments. Edge effects must be rigorously controlled with reflective foil around the perimeter in these small chambers. This talk will summarize our work with super dwarf tomatoes, rice, and wheat. The potential to use super dwarf cultivars of other crop plants will also be discussed.

BLSS 15, Page 36

Failure Analysis: Plant Recovery From Prolonged Darkness

Tracy A.O. Dougher, Jonathan Frantz, Steve Klassen, and Bruce Bugbee

Utah State University
4820 Old Main Hill
Logan, UT 84322-4820
Phone & Fax: (435) 797-2605
E-Mail: tracyaod@cc.usu.edu

Either through power loss or lamp failure, lighting loss is a common failure in controlled environments. Recovery of plant growth from such a failure will be critical to the sustainability of an Advanced Life Support System. Understanding plant response to prolonged darkness can aid in gracefully recovering from these failures. Using canopy gas exchange to quantify response and recovery, we studied canopies exposed to darkness up to 14 days. Canopy respiration fell to a minimum after 24 to 48-h in the dark and the plants were surprisingly tolerant of prolonged darkness. We hypothesized that lowering the temperature during dark periods would help plants better tolerate prolonged darkness. Indeed, canopies that were in the cold during the dark periods recovered much more quickly once light was reestablished with some species recovering to their pretreatment growth rate within 48-h after an 8 day dark period. Surprisingly, the carbon use efficiency (the ratio of net photosynthesis to gross photosynthesis) in all canopies, cold or warm, remained at the same level.

BLSS 16, Page 37

Characterizing Super Dwarf Rice for Use in Advanced Life Support

Jonathan M. Frantz, Derek Pinnock, Steve Klassen, and Bruce Bugbee

Crop Physiology Lab
Dept. of Plants, Soils, and Biometeorology
Utah State University, Logan, UT 84322
Phone/fax: 435-797-2605
E-mail: slvyt@cc.usu.edu

Rice and wheat are the two most significant grain crops in human nutrition. Genotypes and procedures from growing wheat in advanced life-support (ALS) systems are well characterized, but dwarf rice cultivars such as Ai-Nan-Tsao and 29-Lu-1 are too tall (70 cm). The excessive height of these rice cultivars has meant that rice has not been well studied in controlled environments. We recently identified an extremely short rice variety (20-cm tall) with a high harvest index (60%), which we named Super Dwarf rice. We have begun to characterize this cultivar by determining: 1) techniques for optimum stand establishment, 2) root-zone oxygen sensitivity, 3) optimum planting density 4) optimum day/night temperatures, 5) photoperiod sensitivity, and 6) PPF response curves. Stand establishment can be significantly improved by breaking seed dormancy, either by a heat treatment or germination under anaerobic conditions. Super Dwarf grows equally well in an anaerobic root-zone as in an aerobic root-zone. Vegetative biomass was increased by 10% per C with increasing temperature, but seed yield was not significantly increased at the warmer temperatures so harvest index decreased. Super Dwarf tillers profusely, so the optimum planting density is only 200 to 500 plants m-2. Higher planting densities reduced harvest index. The time to heading is increased by 2 days for every hour above a 12-h photoperiod and appears to be hastened by a well-timed stress during vegetative development. Low concentrations of GA3 in the nutrient solution did not reduce the number of days to heading. Yield and yield efficiency were similar to PPF response data for wheat except that wheat can utilize continuous light. Overall, the short height, relatively high yields, and high harvest index, makes Super Dwarf rice an ideal cultivar for ALS.

BLSS 17, Page 38

Sucrose Regulation of ADP-Glucose Pyrophosphorylase Subunit Genes in Tomato Leaves and Fruits

Xiangyang Li, Thomas J. Gianfagna, Jinpeng Xing and Harry W. Janes

Plant Science Department
Rutgers University
59 Dudley Road
New Brunswick, NJ 08901-8520
Tel: 732-932-9711 x252
Fax: 732-932-9441
E-mail: gianfagna@aesop.rutgers.edu

ADP-glucose pyrophosphorylase (AGPase) is one of the major enzymes involved in starch biosynthesis in higher plants. AGPase is composed of 2 subunits designated S and B. There are 3 S subunit genes and 1 B subunit gene in tomato. In a sucrose feeding time course study with detached leaves, there was a significant induction of transcription for agp B, agp S1, and agp S2 within 8 h after incubation. Transcript levels remained elevated for at least 16 h. In contrast, agp S3 was unaffected by sucrose. In fact, transcript levels seemed to decline by 16 h. Glucose also induced AGPase subunit transcription, but mannitol was without effect, indicating that transcription is responsive to sugars rather than to changes in the osmotic potential. Transcription of other genes such as tubulin were unaffected by sugars, demonstrating that the up-regulation of the AGPase subunit genes is not simply a general metabolic response to additional carbohydrate.

Transcriptional activity of agp B, agp S1, and agp S2 was high in the ovary and anthers of the flowers 2 days before anthesis. Activity declined as the flower opened and was re-initiated during fruit set. Transcription of agp S3 was virtually absent in flowers and young fruit. Levels of agp B, agp S1, and agp S2 increased again 5 days after anthesis (DAA) and reach a maximal between 10-20 DAA. For pink fruits (40 DAA), transcription of agp B, agp S1, and agp S2 was almost undetectable. For red fruit, activity again increased, especially for agp S2. When 10-day attached fruit were injected with sucrose there was a significant induction of transcription for agp B and agp S1 within 3 h, and an increase in agp S2 within 24 h, indicating that the sucrose signal transduction pathway is active in both young developing fruit as well as leaves.

BLSS 18, Page 39

Advances in Understanding the Role of Leaf Extracellular Space in the Translocation of Photosynthetically-Derived Sugars

Mend T.H. Librande, Jason S.T. Deveau, and Bernard Grodzinski

University of Guelph
Department of Plant Agriculture
Guelph, Ontario
N1G 2W1

Higher plants are essential for the production of food, oxygen, and water. The key to plant productivity in closed environments is the transport and allocation of sugars manufactured by photosynthesis. Sugars are "loaded" from photosynthetically active cells into vascular tissues (the phloem), which carry them to growing tissue. Historically, the role of the leaf extracellular space (the apoplast) in sugar loading has been overlooked, but recent studies suggest it plays a more pivotal role. The presence of extracellular sucrose-converting enzymes (invertases), sucrose transmembrane transporters (Hi/sucrose contransporters), a high buffering capacity, and the lack of physical connection between photosynthetically active cells and transport vessels (such as in pea) all suggest that sugars traverse the extracellular space. The apoplasm (extracellular fluid) is the initial site of metabolic contact with the atmosphere of a growth chamber, creating the potential for environmental variation to affect photosynthesis and consequently, sugar transport. There is, however, a paucity of data relating apoplastic sugar and proton concentration to photosynthesis. We have developed and tested two methods for studying the uptake and sugar production in the leaf apoplast. In our initial experiments we extracted microlitre volumes of foliar apoplasm by centrifugation and verified its purity using cytosolic enzyme assays. The pH of the apoplasm was measured using Hi-selective microelectrodes, and sugar concentration was measured with high-pressure liquid chromatography. This data was collected from plants exhibiting normal photosynthetic activity and plants exposed to the CO2 concentrations and lowered light levels found in closed environments. Future experiments will involve nondestructive in vivo monitoring and extraction of foliar apoplasm using ion-selective electrophysiology and microsampling. These techniques will help determine how sugar is allocated to growing sinks, how pathogens affect plant productivity, and determine which plants allocate sugar more efficiently in closed environments.

BLSS 19, Page 40

Analysis and Cell Specific Expression of the Promoter of a Tomato ADP-Glucose Pyrophosphorylase Large Subunit Gene (S1) in Transgenic Plants

Jinpeng Xing, Thomas J. Gianfagna and Harry W. Janes

Plant Science Department
Rutgers University
59 Dudley Road
New Brunswick, NJ 08901-8520
Tel: 732-932-9711 x252
Fax: 732-932-9441
E-mail: gianfagna@aesop.rutgers.edu

ADP-glucose pyrophosphorylase (AGPase) is the critical enzyme in the regulation of starch biosynthesis in both photosynthetic and non-photosynthetic tissues. Starch is an important component of yield and quality for many of the plants selected for food production in space. AGPase catalyzes the reaction of glucose-1-phosphate and ATP to ADP-glucose, the substrate for starch biosynthesis. Plant AGPase is composed of two subunits designated S and B. In tomato, 3 isoforms of the S and 1 isoform of the B subunits have been found. The S1 and B transcripts are highly expressed in fruit. An 8.0 kb genomic clone from a tomato library that contains the S1 gene and its promoter was isolated and sequenced. S1 contains 14 introns with the start codon at the beginning of the second exon. There is a TATA box at position -57 in the promoter region. The 3.0 kb promoter region was cut with restriction enzymes to provide 2 truncated promoter regions of 0.8 and 1.3 kb adjacent to the structural gene. The 3 promoter constructs (0.8, 1.3, and 3.0 kb) were analyzed for activity in transgenic tobacco using the promoter-GUS fusion system. The 3.0 kb region was active in various starch-containing cells, such as guard cells, the stem starch sheath cells, the root pith and root cap. The 3.0 kb region was also active in pollen, the ovary and seeds. No activity was observed in the leaf mesophyll. The 1.3 kb region allowed expression in all of the above tissues except the root pith, and the outer layer of the starch sheath of the stem, but for the 0.8 kb region, GUS expression occurred only in the guard cells and flowers. Sequence comparison revealed 2 regions that have high similarity to the potato AGPase S1 promoter, but also significant differences. Unlike the tomato S1, the potato S1 is not expressed in roots.

BLSS 20, Page 41

Effects of Long Term Plant Production on Microbial Community Dynamics in Hydroponic Systems

J.L. Garland1, J.L. Adams, M.S. Roberts, and J. Judkins

1Dynamac Corporation
Mail Code DYN-3
Kennedy Space Center, FL 32899
Tel: (321) 476-4276
Fax: (321) 853-4165
E-mail: jay.garland-1@ksc.nasa.gov.

The composition of microbial communities associated with biomass production modules is an important consideration in the development of bioregenerative systems due to the hazards associated with the potential growth of either human or plant pathogens. Previous studies have established that the overall density of microorganisms in the nutrient delivery systems, particularly those microbes associated with the roots (or rhizosphere), can be very high (e.g., 1011cells g-1 root tissue). Human and plant pathogens introduced into these systems do not persist at significant levels when the diversity of resident communities is relatively high. We have also seen a reproducible increase in diversity during a single plant production cycle, suggesting that long term operation without sanitation events may be the best approach for maintaining the diversity of resident microbial communities and thereby limiting the risk of pathogen growth. Experimental trials using potato and wheat indicated that the diversity of rhizosphere communities was higher earlier in the plant life cycle when young plants (or seeds) were introduced into "aged" systems, i.e. systems containing either older plants or young plants in chambers that were not sanitized after an earlier harvest. This indicates a lack of strict plant age influence upon the successional trends. In fact, the microbial communities of younger (i.e, 21 day old) plants introduced into (i.e. 21 days plants) aged systems were very similar in structure to those communities associated with older (i.e. 84 day old) plants grown in an initially clean system. Current studies are evaluating rhizosphere community development and associated resistance to invasion by a root pathogen in lettuce plants inoculated with microbial communities of various successional ages. These studies reflect the need to utilize an expanding knowledge of microbial ecology to effectively manage microbial communities and optimize plant growth in closed systems.

BLSS 21, Page 42

Use of Hydrogen Peroxide as a Disinfection Agent for Hydroponic Systems

Keith E. Henderson1, Denetia Bell Robinson, Daniel J. Barta and Chris Carrier

1NASA Johnson Space Center
Mail Code EC3
Houston, TX 77058
Tel: 281-483-4802
Fax: 281-483-2508
E-mail: keith.hendersonl@jsc.nasa.gov

Hydrogen peroxide is an oxidizing agent and an effective disinfecting agent that has potential for helping control the growth of biofilm in the nutrient delivery system of hydroponic plant growth systems. In this study it was found that a concentration of 0.5% hydrogen peroxide was equally effective in the reduction of sessile bacteria populations as a conventional rinsing treatment using household bleach followed by dilute nitric acid rinse. Typical results showed a reduction in sessile bacteria from a pre-disinfectant level of approximately 1 X 105 CFU/1 0 cm2 to less than 1 X 101 CFU/10 cm2 This reduction was short lived in duration, as was the bleach/nitric acid treatments as the bacteria concentrations approached pre-disinfection levels after 2 days. Various methods of insuring the removal of residual hydrogen peroxide prior to planting a new crop were also examined. It was found that a platinum on alumna catalyst could be used to remove residual hydrogen peroxide from the nutrient delivery system during a 24 hour period, thus eliminating the need for extensive rinsing. Lettuce plants grown in the plant chamber following the hydrogen peroxide treatments were unaffected except for two specific conditions. One was when the residual hydrogen peroxide was greater than 100 PPM in the nutrient solution which affected the germination and early establishment of the lettuce plants. The second occurred when the nutrient solution was treated with hydrogen peroxide and reused without any replenishment or rinsing. In this instance a reduction in the yield of lettuce yields may have been due to alteration of nutrient solution composition, especially the chelated iron.

BLSS 22, Page 43

Strategies for Enhancing Plant Performance in Bioregenerative Life Support Using a Common Microbial Symbiont

Mark A. Holland

Department of Biology
Salisbury State University
Salisbury, MD 21801
Tel: (410) 548-5590
Fax: (410) 548-3318
E-mail: maholland@ssu.edu

Pink-pigmented, facultative methylotrophs (PPFMs - Methylobacterium spp.) are abundant, non-pathogenic bacteria ubiquitously-distributed on plants. Although they are not well known, these bacteria are co-evolved, interacting partners in plant metabolism. This claim is supported, for example, by the following observations:

    1) PPFMs are seed-transmitted (Corpe and Basile. 1982. Dev. Indust. Microbiol. 23:483-493).
    2) PPFMs are frequently found in putatively axenic cell cultures (Holland and Polacco. 1994. Ann. Rev. Plant Physiol. Plant Molec. Biol. 45:197-209).
    3) Low numbers of seed-borne PPFMs correlate with low germinability (Holland and Polacco. 1994. Ann. Rev. Plant Physiol. Plant Molec. Biol. 45:197-209).
    4) Plants with reduced numbers of PPFMs show elevated shoot/root ratios (Holland. 1997. Rec. Res. Dev. in Plant Physiol. 1:207-213).
    5) Foliar application of PPFMs to soybean during pod fill enhances seed set and yield (Munsanje.1999. PhD Dissertation. University of Maryland Eastern Shore).
    6) PPFMs produce cytokinins (Freyermuth et al. 1996. In Lidstrom and Tabita. eds. Microbial Growth on C1 Compounds, Kluwer).
    7) A pleiotropic mutation in soybean affects both plant and PPFM genes (Holland and Polacco. 1992. Plant Physiol. 98:942-948).
    8) Liverwort tissue in culture requires PPFM-produced vitamin B12 for growth (Basile et al. 1985. Bryologist 88(2):77-81).

These bacteria are already participants in bioregenerative life support systems, and most of us don't know it! Research in my laboratory is aimed at understanding the relationship between PPFMs and plants and at developing strategies that exploit it. Data will be presented to show that PPFM bacteria can be used to alter both agronomic traits and nutritional qualities of crop plants. Applications of this technology to agriculture and biospherics/life support will be discussed.

BLSS 23, Page 44

Ultraviolet Radiation as a Remediation Technique in Controlling Root Diseases: A Case Study with Pythium

M.B. Johnstone,1,3 B. Grodzinski1, H.Yu2, J. Sutton2

1Department of Plant Agriculture
2Department of Environmental Biology,
University of Guelph, Guelph, ON, CANADA, N1G 2W1
Tel: (519) 824-4120 ext. 3775, Fax: (519) 767-0755
3Author to whom correspondence should be addressed; E-mail: mjohnstone@evbhort.uoguelph.ca

The production of essential commodities (O2, H2O, edible biomass, and removal of CO2) by higher plants in bioregenerative life support systems would be seriously limited by the occurrence of disease epidemics. Of major importance in reducing the rate of root infection and disease incidence in hydroponic crops is inactivation or destruction of pathogens in the plant nutrient solution. Among several treatment possibilities is ultraviolet (UV) radiation, one of the preferred sterilization techniques due to cost considerations and observed effectiveness against hydroponic pathogens. 99.99% of zoospores of Pythium aphanidermatum, a common aquatic pathogen found in commercial greenhouses, were inactivated with doses of 20 to 40 mW.s/cm2 as estimated in a laboratory UV flowthrough apparatus. Inactivation increased logarithmically with UV radiation dose. Data will be presented demonstrating changes in Net Carbon Exchange Rate (NCER) of lettuce infected with Pythium, showing loss of gas exchange capacity and reduced productivity in terms of O2generation, CO2 scrubbing, transpired H2O and edible biomass. Current greenhouse and sealed chamber trials are underway to determine the extent of protection offered by UV in minimizing photosynthetic loss due to pathogen infection in lettuce in a recirculating hydroponic system. Data will be discussed with respect to sanitation practices in closed systems.

BLSS 24, Page 45

Spatial Distribution of the Total, Ammonia Oxidizing, and Denitrifying Bacteria in Two Wastewater Treatment Reactors from Bioplex Using Molecular Tools

Lee Kerkhof and Yuko Sakano

Department of Marine & Coastal Sciences
Rutgers, The State University of New Jersey
71 Dudley Road
New Brunswick, NJ 08901
Tel: (732) 932-6555
E-mail:  lkerkhof@rci.rutgers.edu

Bioregenerative life support systems will be necessary for long-term space missions due to the limitations of costs, mass, and energy. Recently, a biological wastewater treatment system was tested by NASA at Johnson Space Center for obtaining potable water using wastewater in a simulated long-term manned space mission. This Phase III test consisted of 4 crew members confined in a test chamber for 91 days. The reactor performance indicated the average TOC removal efficiency was 94% and the average ammonia removal efficiency was 48 %. The water was reused 10 times during the test without any additional re-supply. In this study, spatial distribution and temporal shifts of microorganisms responsible for carbon and nitrogen cycling in two biological wastewater treatment reactors were investigated using terminal restriction fragment length polymorphism (T-RFLP), sequence, and phylogenetic analyses. Biofilm samples were taken from four locations in an Immobilized Cell Bioreactor (ICB) for organic carbon removal, and from three locations in a Trickling Filter Bioreactor (TFB) for ammonia removal. Small subunit rRNA gene sequences were used to characterize the total microbial community and two functional genes were chosen to identify microorganisms responsible for nitrogen removal. These target molecules were the ammonia monooxygenase (amoA) gene for chemolithoautotrophic ammonia oxidizing bacteria and the nitrous oxide reductase (nosZ) gene for denitrifying bacteria. Two distribution patterns were observed in the ICB based on the T-RFLP profiles, while nearly uniform profiles of the three target genes was detected in the TFB. The Proteobacteria appeared to be dominant among 41 partial clonal 16S rRNA sequences obtained from the five clonal libraries (4 from the ICB and 1 from the TFB). A decrease in the species diversity was observed in the two reactors when compared with the inoculum. A total of eight novel partial amoA gene sequences (531bp) was identified in the ICB and TFB, affiliated with either the Nitrosomonas europaea or Nitrosospira multiformis lineage. In the TFB, a population shift from Nitrosomonas-like sp. in the inoculum to both Nitrosomonas- and Nitrosospira-like sp. in the final test day samples. A total of 12 new clonal partial nosZ gene sequences (489bp) was identified in the two reactors and was affiliated with the Achromobacter cycloclastes, Sinorhizobium meliloti, Pseudomonas stutzeri, P. fluorescens, and P. denitrficans clades. In the TFB, only Pseudomonas sp. were observed in the inoculum and the samples taken at the end of the test.

BLSS 25, Page 46

Gas Exchange, Transpiration and Yield of Sweetpotato Grown in a Controlled Environment

Daniel J. Barta1, Keith E. Henderson1, Desmond G. Mortley2, and Donald L. Henninger1

1NASA Johnson Space Center, Houston, TX, 77058
2Tuskegee University Center for Food and Environmental Systems for Human Exploration of Space, Tuskegee, AL, 36088

Primary Author:
Daniel J. Barta
Mail Code EC3
NASA Johnson Space Center
2101 NASA Road 1
Houston, TX 77058
Office: (281) 244-5118
Fax: (281) 483-2508
Pager: (281) 434-5193
E-mail: daniel.j.barta1@jsc.nasa.gov

Sweetpotato was grown to harvest maturity within NASA Johnson Space Center's Variable Pressure Growth Chamber (VPGC) to characterize crop performance for potential use in advanced life support systems as a contributor to food production, air revitalization and resource recovery. Stem cuttings of breeding clone "TU-82-155" were grown hydroponically at a density of 17 plants m-2 using a modified pressure-plate growing system (Patent No. 4860-490, Tuskegee University). Lighting was provided by HPS lamps at a photoperiod of 12h light:12h dark. The photosynthetic photon flux was maintained at 500, 750 and 1000 µmol m-2 s-1 during days 1-15, 16-28, 29-119, respectively. Canopy temperatures were maintained at 28°C:light:22°C:dark. During the light period, relative humidity and carbon dioxide were maintained at 70% and 1200 µl l-1, respectively. Nutrient solution was manually adjusted 2 to 4 times per week by addition of 10X concentrated modified half-strength Hoagland nutrient salts and NaOH to return the electrical conductivity and pH to 1.2 mS cm-1 and 6.0, respectively. At 17 weeks (119 days) from transplanting, a total of 56.5 kg fresh mass of storage roots (84.1% moisture) were harvested from the 11.2 m2 chamber, resulting in a yield 5.0 kg m-2. Harvest index, based on fresh mass, was 38.6%. Rates of net photosynthesis, dark respiration, transpiration, and ethylene production will be reported.

BLSS 26, Page 47

An Open Chamber Design for the Analysis of Whole Plant Photosynthetic Rates

Ron Dutton, Geoffrey Cloutier1, Rodger Tschanz, and Mike Dixon

1Department of Plant Agriculture (Horticultural Science)
University of Guelph, Guelph, Ontario, CANADA , N1G 2W1
Tel: (519) 824-4120 ext. 2616,
Fax: (519) 767-0755
E-mail: cloutier@evbhort.uoguelph.ca
*Author to whom correspondence should be addressed

Growing interest in the life support capabilities of higher plant systems has necessitated the development of controlled environment systems which allow for determinations of plant photosynthetic activity. Since the process of photosynthesis is tightly coupled to the air-revitalization capacity of Advanced Life Support Systems, chambers which provide an in-expensive approach to the analysis of whole plant carbon gain are welcomed.

Nine former 'exposure' chambers were retrofitted with commercially available greenhouse feedback control equipment to produce a photosynthesis analysis system. Chambers are constructed of glass and are 66 cm x 66 cm x 165 cm in size. These chambers operate similarly to small, single leaf cuvettes and are best described as hybrids of differential and compensating type photosynthesis analysis systems. Feedback control algorithms were designed to maintain static outlet CO2 concentrations but variable inlet CO concentrations. Plant photosynthetic activity is thus determined from the difference between individual chamber outlet CO concentrations and a reference (blank) chamber outlet concentration. Chamber performance measures derived from tests in this semi-compensating mode are favorable and indicate good resolution (e.g. ability to detect respiration at small leaf area indices). Calibration of the chambers has been performed using a series of long-term (60-70 day) experiments using Lettuce and Kale with periodic destructive harvest. Results indicate that these chambers are extremely useful in the non-destructive estimation of plant growth from daily carbon gain estimators.

Because these chambers employ 'off the shelf' control equipment and do not require customization, their design is immediately applicable to the retrofitting of traditional growth cabinets. Aspects of employing this design in such cases are also discussed.

BLSS 27, Page 48

Plant Productivity and Photosynthesis at Low Light: A Model Plant System for Controlled Environments

Jorge A. Gutierrez,1 and Bernard Grodzinski2

1Plant Agriculture, Department of Horticultural Science, University of Guelph
2Plant Agriculture, Department of Horticultural Science, University of Guleph

The possibility of using low light and or low temperature tolerant genes to engineer future candidate plants for the space program is being investigated. The implication for sealed environment life support 3ystems is the potential to minimize the energy requirements for crops (e.g. lighting) which in turn reduces the power and weight requirements for illumination systems. Greenhouse crops currently have not been selected for low light (shade) tolerance. However, a number of ornamental crops show potential as a genetic source for modifying candidate species for the space program. For example, many greenhouse growers of snapdragons produce crops on a year-round basis. Four distinct response groups of cultivars to light and temperature have emerged. A possible relation with shade tolerance is that winter cultivars grow better at low light. There is no information that relates response group classification and photosynthetic capacity. Our first tests indicate an improved photosynthetic capacity at a leaf and whole plant level under low light conditions among some groups which correlates with an increased dry matter partitioning. Experiments are also being carried out to determine chlorophyll and sugar contents. A. majus L. (Snapdragon) is a mannitc exporting species. Little is known about the metabolism and transport of alcohol sugars. The biochemical, physiological and genetic basis of low light tolerance in conventional greenhouses crops such as snapdragons, will be discussed.

BLSS 28, Page 49

Differential Sensitivity of Crops to Ethylene and Interactions with Elevated CO2

Steve Klassen and Bruce Bugbee

Utah State University
Department of Plant Soils and Biometeorology

Ethylene is a potent plant hormone that can accumulate in closed growth chambers at levels well above which crop plants are normally adapted. Based on the results of both ground and space studies, ethylene has been clearly identified as an important air contaminant that must be scrubbed in order to prevent yield reductions in wheat. Although present scrubbing technologies can remove ethylene below 50 ppb, this is still 10 to 50 times higher than levels in the field. The potential for system failures must also be recognized and the ability of plants to tolerate ethylene fluctuations evaluated. Our studies indicate that ethylene levels as low as 50 ppb result in a 25 % yield reduction in wheat (cv. USU-Apogee). We have also determined that wheat is most susceptible to ethylene induced sterility around the time of anthesis. Our current efforts focus on the differential sensitivity of wheat cultivars and other crop plants, and potential interactions with elevated CO2. The results of two experiments in progress will be presented. One designed to evaluate the differential sensitivity of two wheat cultivars (Super Dwarf and. USU-Apogee) to 50 ppb ethylene at three levels of CO2 (350, 1200, 5000 ppm). The second mimics previous studies on wheat but investigates the sensitivity of Super Dwarf rice to ethylene levels ranging from 50 to 1000 ppb. Preliminary data indicates ethylene levels as low as 50 ppb significantly reduce yield and delays heading in Super Dwarf rice. Interestingly, levels as high as 20 ppm had no effect on days to heading in wheat. Future research will focus on the effects of short-term ethylene fluctuations and the ethylene sensitivity of other crops.

BLSS 29, Page 50

A System for Measuring Canopy Gas Exchange at the NJ-NSCORT

Konomi Kumasaka
Email: kumasaka@bioresource.rutgers.edu

Gene Giacomelli, Ph.D.
Email: giacomel@bioresource.rutgers.edu

Jim Cavazzoni, Ph.D.
Email: cavazzon@bioresource.rutgers.edu

Department of Bioresource Engineering
Rutgers, The State University of New Jersey
20 Ag Extension Way, New Brunswick, NJ 08901-8500
Tel: 732-932-9753; Fax: 732-932-7931

To improve upon crop modeling work being conducted at the NJ-NSCORT, four environmentally controlled plant growth chambers have been constructed to monitor canopy net photosynthesis and dark cycle respiration of various advanced life support (ALS) food crops (soybean, potato and tomato). The plant chambers [0.55 m2; 0.43 m3] are housed within a walk-in growth chamber [9.3 m2; 28 m3], which provides the basic environmental control for plant growth. Experiments are currently being conducted to determine the response of soybean (cv. Hoyt) canopies to the short- and long-term effects of temperature, CO2 and irradiance.

BLSS 30, Page 51

Performance of the Low Pressure Plant Growth System at Texas A&M University

Ron Lacey, Ph.D.

Associate Professor, Department of Agricultural Engineering
201 Scoates Hall, MS 2117
Texas A&M University, College Station, TX 77843-2117
Office: 409-845-3967
Fax: 409-845-3932
E-mail: ron-lacey@tamu.edu

The Low Pressure Plant Growth (LPPG) facility at Texas A&M University is currently undergoing a significant expansion from two chambers to six chambers. A number of changes are being implemented in the control algorithms and the measurement hardware. The goals of this expansion are to (1) provide the capability to perform replicated experiments at low pressures with ambient pressure control, (2) provide enhanced gas composition measurements in the growth chambers without excess loss of atmosphere from sampling, and (3) perform experiments at pressures as low as 5 kPa (0.05 atm) with independent control over oxygen and carbon dioxide partial pressures. The purpose of this presentation will be to describe and compare the operating parameters of the expanded system with a particular emphasis on the use of the LPPG in support of research related to designing bioregenerative life support systems and subsystems. The system will be characterized with regard to meeting the design parameters, static response of the system, dynamic response of the system, and reliability of the LPPG system performance. A discussion of modeling of the LPPG system response with regards to developing models of plant response will be included. The ramifications of these LPPG system and plant response models on applications of bioregenerative life support systems will be discussed.

BLSS 31, Page 52

Quantifying Differences Between Spaceflight and Ground Plant Experiments: Transpiration Measurements

O. Monje1, G.E. Bingham2, BK. Eames2, J. Conlin2, V. Sytchev3, M.A. Levinskikh3, and I. Podolsky3

1Dynamac Corp., DYN-3, Kennedy Space Center
Tel: 321-476-4326
Fax: 321-853-4220
E-mail: MonieOA@kscgws00.ksc.nasa.gov
2Plants, Soils & Biometeorology Dept., Utah State University
3Institute of Biomedical Problems, Moscow

 Several spacecraft-specific artifacts caused by the altered behavior of fluids and gases in microgravity or by super-elevated CO2 and ethylene-enriched atmospheres may confound plant experiments in space. These artifacts can affect above- or below-ground plant organs and metabolic processes resulting in plant stress and poor growth. Understanding the causes of these artifacts is essential to the design of future flight experiments in order to provide a stress free growth environment in space. Furthermore, identification of these artifacts is needed for conducting appropriate ground control experiments, although, some of these artifacts may not be reproducible on the ground. We conducted a ground control for an experiment in the SVET Greenhouse aboard Mir. The experiment used the Gas Exchange Measurement System (GEMS) to measure canopy transpiration in space. The GEMS recorded several chamber environmental parameters, root zone moisture profiles and the measurement of canopy transpiration in space. These environmental data were used to simulate the Mir cabin air environment during the ground test. An automatic watering system, consisting of a datalogger and moisture probes, was used to approximate the watering regime during the flight experiment. Gas exchange data collected from wheat (cv. Superdwarf) was used to determine canopy transpiration during the ground test. Results from this ground test support the hypothesis that transpiration in space is similar to transpiration from hydroponic plants at I g, probably due to a more uniform distribution of water in the substrate in microgravity.

BLSS 32, Page 53

Yield and Photosynthetic Responses to Elevated CO2 and Relative Humidity in Peanut Grown in Nutrient Film Technique

D.G. Mortley, J. Anfield, D. Hilemen, J.H. Hill, C.K. Bonsi, W.A. Hill, and C.E. Morris

Center for Food and Environmental Systems for Human Exploration of Space and G.W. Carver Agricultural Experiment Station, Tuskegee University, Tuskegee AL 36088.

 Peanut (Arachis hypogaea L.) was exposed to two CO2 and relative humidity (RH) levels in reach-in growth chambers to determine their effects on photosynthesis and subsequent seed yield. In previous experiments, peanut yield and photosynthesis were enhanced when exposed to either elevated CO2 or high RH singly. Four 10-day-old 'Georgia Red' seedlings were planted into each of four nutrient film technique channels and grown for 120 days. CO2 response curves were determined at growthCO2 levels of 400 (ambient) or 1000 mol mol-1 and RH levels of 50 or 85%. Photosynthesis measurements were made at CO2concentrations form 50-1000 mol mol-1. Pod and seed yields were greater at higher CO2 and RH than at ambient CO2 and high RH In contrast, however, pod and seed yields tended to be similar at low RH regardless of the level of CO2 enrichment. Net photosynthetic rates increased with increasing measurement CO2 but were greater at the higher CO2 level. Similar responses were obtained for stomatal conductance and transpiration. These measurements were done at the 50% RH levels. Measurements are still in progress for plants grown at 85% RH.

BLSS 33, Page 54

Ethylene 'Finger Prints': Emission Profiles from Crops Grown in NASA's Biomass Production Chamber

Raymond M. Wheeler1, Barbara V. Peterson2, and Gary W. Stutte2,

1NASA, 2Dynamac, Kennedy Space Center, Florida

Raymond Wheeler
Kennedy Space Center, Florida 32899
Tel: (321) 476-4273
Fax: (321) 853-4165
E-mail: raymond.wheeler-1@ksc.nasa.gov

Ethylene production was monitored throughout growth and development for lettuce, potato, rice, soybean, tomato, and wheat in NASA's Advanced Life Support, Biomass Production Chamber at Kennedy Space Center. An ethylene emission profile or 'fingerprint' has been observed for each candidate crop throughout developmental stages. Ethylene production appears to be to periods of rapid vegetative growth, fruit ripening, and stress.

Data collected from this large-scale test-bed include total and edible biomass, community gas exchange (i.e., photosynthesis, respiration and evaportranspiration), nutrient solution, atmospheric microflora, ethylene, and organic volatile concentration.

The data sets simultaneously track daily nutrient, water and carbon fluxes for whole plant stands throughout the full period of their growth and development. Ethylene has been monitored by gas chromatography with a photoionization detector with an automatic sampling for no less than every six hours throughout the crop growth cycle. The data show a 1:1 correlation of ethylene respiration levels and vegetative growth for hydroponically grown soybean and wheat.

Discontinuities of this correlation during the period of relatively high ethylene concentrations may coincide with events of stem pruning and leaf litter removal. A rise in ethylene respiration just prior to harvest may be related to stand senescence. A burst of ethylene concentration was seen with a change in photoperiod with potatoes.

With appropriate considerations of the limitations of each study, the data can provide information suitable for model development and/or validation of crop growth in controlled environments.

BLSS 34, Page 55

Hybrid Solar and LED Lighting for Lunar and Martian Bioregenerative Life Support

Joel L. Cuello1, Yang Yu, Eiichi Ono, Hiroyuki Watanabe, Takashi Nakamura, and Kenneth Jordan

1Department of Agricultural and Biosystems Engineering
507 Shantz Building
The University of Arizona
Tucson, AZ 85721
Tel: (520) 621-7757,
Fax: (520) 621-3963
E-mail: jcuello@ag.arizona.edu

Hybrid Solar and Artificial Lighting (HYSAL) is a plant lighting strategy whose object is to optimize the electrical power demand of a bioregenerative life support system (BLSS) by minimizing the electrical power usage of artificial lamps by harnessing available solar irradiance. This paper will present and discuss the results of a HYSAL system consisting of light-emitting diodes (LEDs) and a fiberoptic-based Solar Irradiance Collection, Transmission and Distribution System (SICTDS) in comparison with a high-pressure sodium (HPS) reference. The two treatments, receiving equal total moles of photons, will be contrasted in terms of average daily photosynthetic photon flux (PPF), average daily photoperiod, light spectral distribution, spatial PPF distribution on the growing area, average fresh and dry weights, average leaf chlorophyll content per unit biomass, average leaf net CO2 assimilation rate, and average plant light compensation point. The implications of hybrid lighting for BLSS will also be expounded.

BLSS 35, Page 56

Hybrid Solar and Artificial Lighting (HYSAL) in the BIO-Plex Under Terrestrial and Martian Solar Conditions

Jamey Durbin, Johnny Hordge, Alan E. Drysdale and Joel L. Cuello1

1Department of Agricultural and Biosystems Engineering
507 Shantz Building
The University of Arizona
Tucson, AZ 85721
Tel: (520) 621-7757,
Fax: (520) 621-3963
E-mail: jcuello@ag.arizona.edu

Hybrid Solar and Artificial Lighting (HYSAL) is applied to four designs of the Biomass Production Module of the Bioregenerative Planetary Life Support Systems Test Complex (BIO-Plex) to optimize its electrical power demand both in terrestrial and Martian settings. The solar radiation data used were those taken in Tucson, AZ for the terrestrial application and those taken in Chryse Planitia [22.48 degree N, 49.97 degree W, planetographic, 1.5 km below the datum (6.1 mbar) elevation] which was the landing site for the Viking Lander 1 (VL-1) and which is geographically close to the Mars Pathfinder landing site. Commercially available Himawari Solar Concentrators equipped with asopheric lenses and with overall efficiency of 38% will be used together with light-emitting diodes (LEDs). The four BIO-Plex designs with HYSAL systems will be evaluated in terms of equivalent system mass.

BLSS 36, Page 57

High Pressure Sodium Lamp Lighting Analysis and Design for The BIO-Plex Plant Growth Chamber

Shaun Gartenberg, M.Eng.1, Louis D. Albright, Ph.D.1, and Daniel J. Barta, Ph.D.2

1Department of Agricultural and Biological Engineering
Riley-Robb Hall, Cornell University
Ithaca, New York
Tel: 607-254-6772
Fax: 607-255-4080
E-mail: scg6@cornell.edu
2Life Support and Habitability Systems
Johnson Space Center, NASA
Houston, Texas

This paper describes details of a computer-based design for High-Pressure Sodium (HPS) lighting to be used in the BIO-Plex plant growth chamber at NASA's Johnson Space Center facility. The overall goal of the BIO-Plex is to create a self-sustainable colony on Mars capable of, among other things, growing its own food in a specially designed hydroponics chamber. Due to physical and economical restrictions, space in this growth chamber is limited. Maximum efficiency is therefore critical in terms of power consumption, light output, and light uniformity.

The BIO-Plex requires intense light over a limited area to maximize plant growth, and excessive radiant heating of plants is a considerable concern. Therefore, a specially designed 400-watt water-jacketed HPS lamp was considered for the design. By enclosing the lamp in an outer jacket of glass, water is pumped around the inner lamp. The water carries away approximately half of the lamp's heat and nearly eliminates infrared heating of plants. The goal, therefore, was limited to determining the most efficient and effective placement of lamps in the chamber without regard for infrared heating.

Photopia®, a 3-D luminaire analysis and design program created by Lighting Technologies, Inc., was used for the designs. A mean Photosynthetic Photon Flux Density of 1500 mol/m2s was desired, while maintaining as much uniformity as possible across planes situated beneath the light box. Lamp placements within the BIO-Plex, and reflector designs, were considered in detail. Several designs, using standard, non-jacketed lamps, and water-jacketed lamps were completed and are described in this paper. Specially designed light-spreading additions to standard luminaires (to remove hot spots directly under the lamps) are proposed and their benefits are described. Additionally, the usefulness of commercially available, lighting design computer programs, applied to plant lighting, is illustrated through the designs.

BLSS 37, Page 58

Performance of Salad-type Plants Grown Under Narrow Spectrum Light-emitting Diodes (LEDs) In a Controlled Environment

Gregory D. Goins- Principal Investigator

Dynamac Corporation
Mail Code DYN-3
Building 60505 CCAFS
Kennedy Space Center, Florida 32899
Tel: 321-476-4320
Fax: 321-853-2859
Email: gregory.goins-1@ksc.nasa.gov

A primary challenge for supporting plants in a bioregenerative life advanced life support system is to provide as much photosynthetically active radiation (PAR) as possible, while conserving electrical power. In addition, the spectral composition of light is critical with regard to plant development and morphology. Accordingly, light-emitting diodes (LEDs) and microwave lamps are promising technologies, which have several appealing features for applications in controlled environments. Light-emitting diodes can illuminate a high output near the peak absorption regions of chlorophyll while giving virtually no near-infrared radiation. The sulfur-microwave electrode-less high-intensity discharge (HID) lamp uses microwave energy to excite sulfur and argon which produces a bright continuous broad-spectrum white light. Compared to conventional broad-spectrum sources, the microwave lamp is highly efficient, and produces limited amounts of UV and infrared radiation.

Radish and spinach plants were grown for 28 days under 9 different lamp banks with a 16-hour light/ 8-hour dark photoperiod. Three lamp banks represented broad-spectrum white light sources (microwave, high-pressure sodium, and cool-white fluorescent). The remaining six lamp banks were LED arrays filled with a given wavelength of red (664, 666, 676, 688, 704, and 735 nm) LEDs. Each array contained single rows of blue LEDs (474 nm) evenly distributed within multiple rows of red LEDs. All plants received 250 µmolm-2s-1 PAR except those grown under the 704 or 730 nm LED arrays. Harvests were conducted at 14, 21, and 28 days after planting. At each harvest, plant measurements included total biomass yield, net leaf photosynthesis rate, leaf stomatal conductance, and leaf chlorophyll concentration, specific leaf area, and leaf number. The work described here will give the Advanced Life Support Program insight into the feasibility of using LEDs and/or microwave lamps as an innovative alternative light source for plant biomass production.

BLSS 38, Page 59

Development of Solar Plant Lighting System for Life Support in Space

Takashi Nakamura and John A. Case
Physical Sciences Inc.

Joel L. Cuello and Darren A. Jack
University of Arizona

Brian Comaskey and Milt Bell
Lawrence Livermore National Laboratory

 This paper discusses results of our research on development of the Optical Waveguide (OW) solar plant lighting system. In this system, solar radiation is collected by concentrator which transfers the concentrated solar radiation to the OW transmission line consisting of low loss optical fibers. The OW line transmits the solar radiation to the selective beam splitter where the solar spectra is divided into two components: plant lighting spectra (400 nm < l < 700 nm) and non-plant lighting spectra (l < 400 nm and l > 700 nm). The plant lighting spectra, or photosynthetically active radiation (PAR), are transmitted to the plant growth chamber where the solar radiation from the optical fibers is optimized for plant lighting. The non-plant lighting, or non-PAR, spectra are transmitted to either power generation device or process heat generation device for useful energy conversion. The features of the OW solar plant lighting system are:

1. Solar radiation, collected by a concentrator or array of concentrators, can be transmitted via a flexible, lightweight OW transmission line to the plant growing unit inside of the spacecraft or space colony;
2. Only the plant growing component of the solar radiation will be transmitted to the plant growing chamber, thereby minimizing heat generation inside the chamber ;
3. The portion of solar radiation not utilized for plant growth can be used for electric power generation or for other useful purposes;
4.  When solar light is not available, the system, through the power stored, can deliver to the plant growth chamber the required photons from the artificial lighting source; and
5. Solar radiation transmitted through the OW transmission line can also be used for illumination and for heating, contributing to crew comfort.

 Since 1995, authors have been conducting NASA funded research programs to develop the technologies for solar plant lighting 1. In these programs we have developed key optical components and system to utilize solar energy for plant growth in space. The optical components and the system tested include: reflective and refractive concentrators; several high numerical aperture (NA) optical fibers; cable connection devices; spectral conditioning device; and light distribution device. This paper discusses history of the programs, lessons learned in our endeavor, and future directions for the advanced life support in space.

[1] These research programs were supported by NASA/JSC and KSC under contracts NAS9-19279, NAS10-97056, and NAS9-98135.

BLSS 39, Page 60

Use of Solar Stationary Orbits over Mars for Biological Life Support

Eiichi Ono and Joel L. Cuello

Department of Agricultural and Biosystems Engineering
403 Shantz Building
The University of Arizona
Tucson AZ 85721
Tel: (520) 621-7757
Fax: (520) 621-3963
E-mail: eiichi@u.arizona.edu

Solar stationary orbits, or sun synchronous orbits, are unique orbits that satellites use to pass over the same latitude on a planet at the same sun time. These orbits are heavily used for meteorological satellites over Earth. A significant feature of sun synchronous orbits relative to a biologically-based life support system (BLSS) is that they constitute trajectories where solar energy is continuously available. Hence, for a BLSS set on a solar stationary orbit, solar radiation could be harnessed without interruption either through transformation into electricity or through direct conveyance and distribution over growing plants in the orbiting biomass production chamber. Also, sun-tracking devices would be rendered unnecessary and the effects of the planet's atmosphere for reducing the amount of light passing through it would be circumvented. The use of a sun-synchronous orbiting BLSS over Mars is appealing particularly since only 44% as much solar radiation reaches the planet compared with that on the Earth. This paper will discuss the rationale for each of the various applications of solar stationary orbits for Martian life support. Also, the photosynthetically active radiation (PAR) available on Mars stationary orbits are calculated.

BLSS 40, Page 61

Candidate Lighting Technologies for Advanced Life Support Biomass Production

J. Sager, G. Goins, S. Young, and C. Paty

One of the most difficult problems in developing an efficient bioregenerative life support system is the high energy use in growing plants. It is essential for the bioregenerative project to develop new technologies and horticultural methodologies to significantly reduce the energy demands for these systems without undue penalties for volume or other resources. The development and validation of energy efficient lighting systems is essential for plant growth in bioregenerative life support, an enabling technology for the exploration and development of space (Lunar/Mars). The ultimate goal is to significantly improve the efficiency of converting electrical energy into edible plant biomass. Lighting for plant production is the biggest single energy demand of a bioregenerative life support system and this technology is a high priority in the Advanced Life Support Program (ALS). Current electric lamps are 15-35% efficient in conversion of electrical energy to light. Promising lighting technologies are currently under development through the ALS Biomass Production Technical Task, the salad crop production ALS grant, technology development through SBIR contracts, and KSC discretionary funding. These include improvements in electrical conversion, quantifying radiant conversion efficiencies, evaluating photosynthetic efficiencies and plant growth under the different lamps to define the system efficiency, developing more efficient lighting systems methods of transporting and distributing PAR to the plant, and exploring new components and concepts in plant lighting. Integration of these lighting technologies into a testbed/specific application will result in reduced equivalent system mass (ESM) and improved reliability. Promising technologies will be evaluated and integrated into the crop production systems at KSC. Ultimately, these lighting systems will have application in the ALS testbed, BIO-Plex, could be used in plant flight hardware for the Space Shuttle and International Space Station, and could be enabling technologies for the exploration and development of space.

BLSS 41, Page 62

Direct Recycling of Graywater Containing Different Surfactant Types in Plant Production Systems

J.L. Garland1, L.H. Levine, J. Judkins, J.L. Adams, and N.C. Yorio

1Dynamac Corporation
Mail Code DYN-3
Kennedy Space Center, Fla. 32899
Tel: (321) 476-4276
Fax: (321) 853-4165
E-mail: jay.garland-1@ksc.nasa.gov

Preliminary studies have indicated that direct addition of human hygiene water to hydroponic systems and subsequent collection of atmospheric condensate may be a feasible method for water recycling in a bioregenerative life support system. This approach is based on degradation of the surfactant(s) contained in the hygiene water by microorganisms within the system to prevent accumulation of the surfactant to phytotoxic levels. Previous studies have focused on Igepon, a sulfonated amide surfactant proposed for use on the International Space Station. A wider range of surfactants may be desirable in order to widen personal care options for ALS crew members and to limit addition of undesirable cations (e.g., Na) into the systems. Seven additional surfactants were identified for study based on their common use in commercial cleansing products and, in some cases, absence of Na as a counter ion. The phytotoxicty of the surfactants could be ranked based on seedling bioassays as follows: Igepon < cocoamideopropyl betaine < carboxylate soaps (both Na- and K- containing) <sodium laureth sulfate =sodium ether sulfate = ammonium lauryl sulfate < polyoxyethoxy lauryl ether. Follow-up studies were designed to test the effects of long term recycling of three representative types of surfactants: 1) sodium laureth sulfate, an anionic surfactant commonly found in shampoos, 2) polyoxyethoxy lauryl ether, a non-ionic surfactant increasingly used in laundry and cleaning applications, and 3) Mirataine Bet C-30, an amphoteric surfactant commonly found in body shampoos. These tests will evaluate phytotoxicity, surfactant degradation, and microbial dynamics during full term experiments with wheat in which surfactant-containing water (300 ppm) is used for as the sole source of liquid replenishment..

BLSS 42, Page 63

Investigation of Greenhouse Grown Swiss Chard in Mixtures of Compost and Mars Regolith Simulant

Matthew R. Gilrain1, John A. Hogan1, Logan S. Logendra2, and Robert M. Cowan1

1Department of Environmental Sciences and NJ-NSCORT
Cook College and New Jersey Agricultural Experiment Station
Rutgers, The State University of New Jersey
2Department of Plant Sciences, New Jersey Agricultural Experiment Station and the NJ-NSCORT Rutgers, The State University of New Jersey

Rutgers, The State University of New Jersey
Department of Environmental Sciences
14 College Farm Road
New Brunswick NJ 08901-8551
Tel: 732-932-6684
Fax: 732-932-8644
E-mail: mgilrain@eden.rutgers.edu

The growth of Swiss chard (Beta vulgaris) in compost, Mars regolith simulant, and mixtures thereof, was studied for application in Advanced Life Support (ALS) systems, particularly Mars/lunar based operations. The purpose was to begin characterizing a sustainable biomass production method based on compost derived from inedible biomass. Compost serves both as a means of recycling plant nutrients while improving the physical qualities of regolith as a plant growth medium. Swiss chard was selected due to its rapid growth and multiple harvest capabilities, and because it was a potential ALS crop candidate for which there was little available data.

The plant growth media were a 1.5-year-old stabilized municipal leaf compost and Mars regolith simulant (JSC Mars-1, <10 mm size fraction). The ratios of compost to simulant used were 1:0, 1:3, 1:1, 3:1, and 0:1. Several greenhouse experiments were conducted on these mixtures utilizing a recirculating irrigation system. Major parameters examined included: tissue mass (fresh and dry); leaf area; irrigant utilization; and physical/chemical characteristics of plant growth media and plant tissue. It was shown that the1:0, 3:1, and 1:1 ratios produced statistically equivalent yields, which were typically greater than the 1:3 and 0:1 ratios. Overall observations suggest that amending the Martian regolith simulant with compost increased plant growth, primarily due to physical (e.g. water holding capacity) and chemical factors (e.g. increased nutrient availability). It is therefore possible that a planetary-based ALS system could locally produce a solid plant growth medium, thereby potentially expanding plant production capabilities. In addition to studying compost/simulant mixtures, comparisons where made between Swiss chard and lettuce (Lactuca sativa), drip and spray irrigators, and multiple cropping on the same medium.

BLSS 43, Page 64

Microgravity Plant Nutrient Experiment: Year 1 Activities

Howard G. Levine1 and Thomas W. Dreschel

Dynamac Corporation, Life Sciences Support Facility, Kennedy Space Center, FL 32899

1Gravitational Biology Laboratory
Life Sciences Support Facility
Mail Code DYN-3
Kennedy Space Center, FL 32899
Tel: 321-476-4321
Fax: 321-853-4220
E-mail: Howard.Levine-1@ksc.nasa.gov

There is a need for microgravity-based plant culture nutrient delivery systems (NDS's) for both bioregenerative Advanced Life Support and plant research functions. The provision of adequate levels of water (without causing water logging) and oxygen to the root zone are the most crucial components deterring major advancements in this area. The dominance of the surface tension of water under microgravity conditions has often been found to lead to either severe water-logging or excessive drying in the root zone. Consequently, differences in plant growth responses between spaceflight experiments and their ground controls are expected based merely upon differences in moisture distribution patterns between the two conditions. This project will address the question of "comparability of environmental conditions" between the spaceflight and ground control experiments for both a porous tube plant NDS and a substrate-based NDS by employing 3-6 different wetness level treatments for both of these approaches. It is anticipated that different pre-set wetness levels than those used on Earth will be required to support optimal plant growth in space. Dry seeds will be loaded three days prior to Orbiter lift-off, and the system will be initiated by the crew on-orbit. A minimum of 72 wheat (Triticum aestivum) seeds (for each of the two NDS's) will be imbibed and germinated on-orbit. Time-lapsed video recording of the plants will monitor growth over time. At recovery, the plants will be measured, and extensive tissue analyses relating to gene expression and stress-associated metabolites will be undertaken.

BLSS 44, Page 65

Interactions of Human Essential Nutrients with Crops and Nutrient Solutions in a Bioregenerative Life Support System

C.L. Mackowiak1, P.R. Grossl1, R.M. Wheeler2, M. Grafe3 and M. Eick3

1Dept. Plants, Soils, and Biometeorology, Utah State University, Logan, UT 84322
2NASA Office of Biomedical Operations, Kennedy Space Center, FL 32899
3Virginia Polytechnic Institute & State University, Blacksburg VA 24061.

There are approximately nine elements that are noted as essential for humans but not for plants. In a Bioregenerative Life Support System (BLSS), it is possible for these nutrients to enter the crop production system via nutrient recovery from human waste streams. Successful recycling of human nutrients in a BLSS will require knowledge of nutrient dosage effects on crop production, nutrient tissue partitioning within crop biomass, and nutrient geochemical fates within nutrient solutions. The fate of sodium (Na), fluoride (F), iodine (I), and arsenic (As) have been examined, relative to these requirements. Lettuce, radish, spinach, and beet growth were all inhibited by 8.0 x 10-2 M Na; rice by 2.0 x 10-3 M F; radish by 1.0 x 10-4 M As; and rice by 1.0 x 10-5 M I. Based on a BLSS "worst case scenario" where 500 liters of nutrient solution would support crops for one person and allowing for no nutrient removal by crops, the time to reach the above toxicity levels (crop production time limits) were established. These were 1.1, 13.0, 11.6, and 257 years for Na, F, I, and As, respectively. The Na time limit could be greatly increased by reducing Na in the human diet (proposed by some human nutritionists), recovering some Na from urine prior to incorporating the urine back into the crop production system, and using crops that sequester Na. Chemical equilibrium models were useful in assessing possible nutrient redox and sorption reactions within the nutrient solution, such as AsO43-:AsO33- and I-:IO3- activities, along with estimates of F solid complex formation with other nutrients. In addition, these models were capable of incorporating soluble organic waste constituents into their equilibrium calculations. Consequently, a more complete and robust geochemical database can be created for use in constructing BLSS nutrient mass balances.

BLSS 45, Page 66

Nutrient Recovery and Biological Degradation of Inedible Biomass for Advanced Life Support Systems

Rebecca J. Manis, Christos Christodoulatos, and David A. Vaccari

Center for Environmental Engineering
Stevens Institute of Technology

Recycling of micronutrients such as nitrogen and phosphorous bound to inedible plant biomass, and biomass degradation, are integral parts of an Advanced Life Support (ALS) system for space travel. Leaching and biological treatment of inedible biomass could provide the means for nutrient recovery and biomass degradation. The ability of the fungus Phanerochaete Chrysosporium (P.chrysosporium) and activated sewage sludge to mediate inedible biomass destruction and recovery of nutrients are investigated in this study. In addition the effect of particle size on recovery and biomass degradation are studied. P. chrysosporium is known for its ability to degrade cellulose and lignin, two major components of inedible plant material. Crops including potato, tomato, sweet potato, soybean, rice and wheat crops will be treated. Biomass is milled and then separated into four different particle sizes (>250 mm, 250  mm, 600  mm, 1180  mm). After leaching with de-ionized water, the remaining biomass is then inoculated with either P. chrysosporium or activated sludge for degradation. One mL of liquid cultured P. chrysosporium is used to inoculate a one percent biomass and de-ionized water solution in order to accommodate degradation (to ensure active liquid cultures, new liquid cultures are re-inoculated at two week intervals). Two mL of activated sludge are used to inoculate an identical solution. Total suspended solids analysis is conducted at four, eight, twelve, twenty-four, thirty-two and forty-six day intervals in order to determine reduction of solids to water and carbon dioxide by the inoculates. Nutrients and micronutrients will be measured to determine leaching and biodegradability success.

BLSS 46, Page 67

The Long Term Effects of High Ammonium/Nitrate Ratios on Wheat Growth and Nitrification in Hydroponic Culture

D.J. Muhlestein1, T. Hooten, J.M. Norton, and B. Bugbee
Plants, Soils, & Biometeorology Dept., Utah State Univ.

1Utah State University
Plant, Soils, & Biometeorology Dept.
4820 Old Main Hill
Logan, UT 84322-4820
Tel: (435)797-2265
Fax: (435)797-2600
E-mail:  SLBDN@cc.usu.edu

Conversion of NH4+ to NO3- in advanced life support systems can be difficult. Supplying NH4+ directly to the plants could eliminate the need for a nitrifying bioreactor. Many plant physiology textbooks indicate that NH4+ is toxic to plants, but we now know that this may not be true when rhizosphere pH is controlled. However, the long-term effects of high NH4+/ NO3- uptake ratios on growth and yield are poorly understood. The counterbalancing ion (SO42- vs. Cl-) to NH4+ in the root-zone may be important to plant growth and nitrification. In four studies, wheat was grown to maturity with NH4+/ NO3- ratios from 0 to 0.85 in recirculating hydroponic solution. In the third and fourth studies, NH4+ was supplied as either (NH4)2SO4, NH4Cl, or both. The high NH4+ treatment (85% NH4+) reduced seed yield by 20% in the first two studies, but yield was not reduced in the third and fourth studies. Chloride and sulfate were equally effective as counterbalancing ions for NH4+. Nitrification in hydroponics could alleviate problems associated with high NH4+. Indeed, some research suggests that much of the N uptake in high NH4+ systems is actually  NO3- from microbial conversion. Preliminary studies indicate that significant nitrification can occur in hydroponic systems when they are inoculated with nitrifying organisms, however, nitrification in non-inoculated systems was insignificant.

BLSS 47, Page 68

Nitrogen Supplied Through Rhizobial Dinitrogen Fixation for Hydroponic Peanut Production

A.A. Trotman, C.A. Hamilton and R. Grider

Tuskegee University Center for Food and Environmental Systems for Human Exploration of Space, Tuskegee Institute, AL 36088

Peanut [Arachis hypogea (L.)] roots were embedded in perlite, and exposed to nutrient solution via drip irrigation. Mineral nitrogen applications and rhizobial inoculation were compared using peanut plants grown hydroponically in pots and growth channels using three different methods of inoculation (inoculum-free, surface-inoculation, and reservoir inoculation). Rhizobial efficiency was determined by peanut reproductive growth parameters (flowering, gynophore, production, nodulation, plant height, and pod yield. Total plant N content was analyzed by Kjeldahl method. The light source consisted of fluorescent tubes and two hanging drop lights. Rhizobial efficiency was determined by color following nodule excision. Phenotypic characteristics of Rhizobium used in inocula were determined by plasmid and genomic DNA analysis. Rhizobial inoculation proved comparable to mineral N application, however, variable effects were observed with respect to days to flowering and gynophore production, when both methods of inoculation were compared. Rhizobial inoculation did not affect pod yield. The results of this study will be instrumental in determining inoculation methods needed to sustain hydroponic culture of peanut and supply fixed N in an Advanced Life Support System.

BLSS 48, Page 69

Nitrogen As a Controlling Parameter In Bioregenerative Life Support System-Nitrification/Denitrification Under High Nitrogen Concentration

Dragoljub Bilanovic1*, Joost Groeneweg** and Joan Mata-Alvarez***

1Department of Biology,
Salisbury State University, Salisbury, MD 21801
Tel: (410) 548 9189
Fax: (410) 543 6433
E-mail: ddbilanovic@ssu.edu

The development of an advanced self-sustaining life support system capable of providing potable water and clean atmosphere depends, on the one hand, on an ability to conduct nitrification under high NH4/NH3-N concentration and, on the another, on an ability to conduct denitrification under higher NO3/NO2-N concentration. This statement is supported, for example, by the following observations:

Bilanovic D., P. Battistoni, F. Cecchi., P. Pavan and J. Mata-Alvarez (1999), Denitrification Under High Nitrate Concentration And Alternating Anoxic Conditions, Water Research Vol. 33, No. 15, pp 3311- 3320.

Liabres P., Bilanovic D. and J. Mata-Alvarez (1996), A Kinetic Study Of An Anaerobic-Aerobic Combined System To Treat Domestic Sewage In Coastal Areas. Proc. IAWQ-NVA conference on Advanced Wastewater Treatment, 23 - 25 September, Amsterdam Holland. pp. 523 -530.

Green M.,Schnitzer M.,Tarre S.,Shelef G., Bilanovic D. and C.J. Soeder (1995), Heterotrophic Denitrification Using Fluidized Bed Reactor. Acta Hydrochim. Hydrobiol. 23, 2, 61-65.

Bilanovic D., Groeneweg J., Muckenheim Th., Schwuger M. und C.J. Soeder (1992), Verfahren zur Abwasserreinigung mit Stickstoffelimination und dafur geeignete Anlage. Deutsche Patentschrift DE 4231628 C 1

Data pertaining to research on nitrification/denitrification under high N concentration conducted at Salisbury State University*, Forschungszentrum Juelich - Germany** and University of Barcelona Spain*** will be presented. Our efforts to use nitrogen as a controlling parameter in an integrated photosynthetic / chemotrophic / heterotrophic system will be discussed also.

BLSS 49, Page 70

Characteristics and Operational Parameters for an Automated Bioreactor System for Biological Degradation of Inedible Crop Residue

M. Calhoun, A.A. Trotman and H. Aglan

Tuskegee University Center for Food and Environmental Systems for Human Exploration of Space, Tuskegee Institute, AL 36088

An automated, aerobic biodegradation system has been developed to facilitate the production of an effluent suitable for delivery as stock replenishment to a hydroponic growth system. The system was designed to use either fresh or dried inedible plant material (biomass). Due to the dynamic nature of the biodegradation process, filtration needs also change as particle size decreases. The current system includes a containment subsystem, which sieves particles to 250 microns. This is adequate to ensure that the system lines will not clog during sample measurements. Temperature, pH and electrical conductivity (EC) measurements were recorded from a sampling loop. The temperature, pH and EC electrodes are housed in an inline manifold. The system was equipped with a pH control system. The acceptable pH range was set to 6.8 - 7..2. Whenever the pH of the solution was recorded to be outside of the range, a metering pump was triggered to pulse 0.5 mL per stroke of acid or base into the bioreactor. An air pump, providing continuous airflow, maintained aerobic conditions inside the bioreactor. The air pump has a flow rate range of 2 L/min to 10 L/min, which is also vigorous enough to thoroughly agitate and mix the solution. The system is also capable of measuring changes in CO2 and O2, by sampling the off gases.. A PC using LabVIEW software controls all system pumps and stores the data. The long-term performance of the system was evaluated through experiments on both dry and fresh biomass. Changes in EC and pH measurements indicated that degradation was occurring in the reactor. Examination of the filtered substrate at harvest qualitatively revealed a considerable decrease in particle size.

BLSS 50, Page 71

A Bioconverter for Advance Life Support System Solid Wastes

Cheryl Frazier-Atkinson1, James Wright2, and John C. Sager3

1James Wright Environmental Management, Inc.
NASA Mail Code JJ-G
Kennedy Space Center, FL 32899
Tel: 321-476-4281
Fax: 321-853-4165
E-mail: FraziCM@kscgws00.ksc.nasa.gov

2Wright Environmental Management, Inc.
9050 Yonge St., Suite 300
Richmond Hill, ON L4C 9S6, Canada

3NASA, Mail Code JJ-G, Kennedy Space Center, FL 32899

Long-term space missions will require recycling of wastes to maintain self-sufficiency, reduce re-supply costs, and lower overall system mass. Aerobic composting of solid wastes can provide stabilization and volume reduction, enhance nutrient recycling, and encourage pathogen reduction (both plant- and fecal-borne), but will pose little, if any, threat to crew safety. Preliminary studies at Kennedy Space Center have shown that the volume of Advanced Life Support-generated solid wastes can be reduced through aerobic composting. The vessels used in these experiments were not optimal - most controls were manual, mixing required removal from the vessel, moisture control was difficult, and the mass/volume ratio was not conducive to self-heating. A newly designed bioconverter (RSB) with biofiltration is currently in use at Kennedy Space Center. At least 6 kg of organic solid wastes was composted in each RSB run. The mix was able to self-heat and maintained temperatures above those of the insulating heat jacket. Carbon dioxide production ranged between 20,000 and 50,000 ppm during the initial heating phase. Volume reduction was greater than 50 % within four days. Approximately 700 mL of nutrient-rich leachate was also collected during this period. The exit air stream from the RSB passed through a three-stage biofilter; no objectionable odors were detected. Experiments are underway to examine the composition of the air stream entering and exiting the biofilter, and to examine the feasibility of biofilter use in a closed environment. Other experiments planned for this unit will involve molecular biological techniques to track the fate of pathogens that were introduced into the initial mixture and throughout the composting process.

BLSS 51, Page 72

Composting of Advanced Life Support Plant Inedible Biomass: Use of Compost as a Plant Growth Medium and Biofiltration of Exhaust Gases

John A. Hogan, Matthew R. Gilrain, Javier Ramirez, Robert M. Cowan, and Peter F. Strom

NJ-NSCORT and Department of Environmental Sciences
Cook College and New Jersey Agricultural Experiment Station
Rutgers, The State University of New Jersey

Rutgers, The State University of New Jersey
Department of Environmental Sciences
14 College Farm Road
New Brunswick NJ 08901-8551
Tel: 732-932-6684
Fax: 732-932-8644
E-mail: hogan@aesop.rutgers.edu

A potential advantage in utilizing composting as a biological waste treatment technology for the treatment of plant inedible biomass produced in Advanced Life Support (ALS) systems is the utilization of the stabilized compost as a plant growth medium. Successful operation of this system requires the determination of the period and extent of processing required to produce a compost suitable for plant growth. Therefore, this study was designed so as to operate a composting system in batch mode and provide seven mid-course compost samples (~15L) for use in plant growth experiments (wheat). In conjunction, a series of physical/chemical/biological tests are conducted on each compost sample to allow correlation analysis with plant growth.

The composting feedstock consists of shredded and dried inedible residues from ALS crops (wheat, soybean, tomato) produced with nutriculture systems. This feedstock is mixed 1:1 with a Martian regolith simulant (JSC MARS-1), and leached to decrease conductivity. Wheat plant growth trials will be conducted in greenhouses, using a fertilizer solution in a single pass mode (no recirculation).

The composting system is comprised of a 350 L cylindrical reactor covered with a dual zone (upper and lower) heating/insulation system that can be controlled via either an automatic temperature differential conductive heat flux control system (allows the compost material to "self-regulate") or operated at a pre-set temperature. Ventilation is employed in a single use mode, and is controlled both for oxygenation and matrix temperature feedback control. The condensed composting exhaust gases are then conducted to a 100L temporary gas storage system (to compensate for intermittent composting ventilation) and then to biofilter systems. Preliminary biofiltration experiments were conducted in order to characterize the demands of biologically treating trace air contaminants from composting. This project is ongoing and the results from composting, plant growth, and biofiltration will be presented as available, and the implications of system integration discussed.

BLSS 52, Page 73

Composting of Advanced Life Support Plant Inedible Biomass: Process Behavior and Exhaust Trace Air Contaminant Analysis

John A. Hogan, Weerasak Lertsiriyothin, Robert M. Cowan, and Peter F. Strom

NJ-NSCORT and Department of Environmental Sciences
Cook College and New Jersey Agricultural Experiment Station
Rutgers, The State University of New Jersey

Rutgers, The State University of New Jersey
Department of Environmental Sciences
14 College Farm Road
New Brunswick NJ 08901-8551
Tel: 732-932-6684
Fax: 732-932-8644
E-mail: hogan@aesop.rutgers.edu

Composting is a potential biological waste treatment technology for Advanced Life Support (ALS) systems, particularly when large quantities of inedible plant biomass are generated. Composting can serve to decrease mass, volume and water content, as well as stabilize and sanitize the material. Composting may also serve as a pre-treatment system prior to extraction for nutrient recovery or incineration, and the compost may serve as a plant growth substrate.

In this vein, four candidate ALS crops (wheat, soybeans, potatoes, and tomatoes) were grown to maturity in a greenhouse using 1/2 strength Hoagland's solution. The inedible portion was collected and pre-processed for composting by either using a shredding machine (Treatment 1) or hand chopping (Treatment 2), with partial drying as required. Using 14 L reactors, the material was processed in a composting simulation apparatus that allows for automatic ventilation based both on baseline for aeration and temperature feedback for matrix temperature regulation. Realistic self-heating of the matrix is accomplished through computerized conductive heat flux control. The ventilative temperature feedback set point was 55oC. The material was processed for a total of 137 days, with multiple midcourse samplings.

To evaluate the potential demand exerted on an ALS trace contaminant control system by a composting system, volatile organic contaminant generation was determined by collecting ventilation exhaust gas and condensate samples, with subsequent analysis using short path thermal desorption/GC-MS. Other measured experimental parameters included: microbial heat production; microbial water production and removal from matrix; ammonium volatilization and a limited nitrogen balance; pH of matrix and condensate; oxygen, carbon dioxide and methane levels in exhaust gas; composting matrix mass, volatile solids, and volume reduction; and ventilation requirements. Overall composting behavior, a comparison between pre-treatment methods, volatile contaminant production, and the integration of composting into ALS systems will be addressed.

BLSS 53, Page 74

Profiling of Volatile Organic Compounds (VOC's) Emissions during Cooking Extrusion of Wheat and Rice Flour Products

Weerasak Lertsiriyothin

Department of Food Science
Rutgers, The State University of New Jersey
65 Dudley Rd.
New Brunswick, NJ 08901
Tel: (732) 932-9611
E-mail: lertsiwe@eden.rutgers.edu

 The volatile organic compounds (VOC's) generated during a food extrusion process were qualitatively and quantitatively determined. A single screw cooking extruder (C.W. Brabender, S. Hackensack, NJ) was used to extrude several cereal-based expanded type products. Volatile and semi-volatile organic compounds emitted from the die head during the extrusion process were collected into large, gastight, Tedlar® bags using a custom designed apparatus. The VOC's were subsequently analyzed by purge & trap- thermal desorption-gas chromatography-mass spectrometry (P&T-TD-GC-MS) methodology employing internal standards. Wheat and rice flours with moisture contents of 16 and 18 % were separately extruded and the VOC's profiles were evaluated. The rate of VOC generation was calculated for each product at the two moisture contents and the types and amounts of VOC's emitted were correlated with the extrudate ingredient composition. This VOC's generation data can be used to model the types and concentrations of compounds expected to be released into the atmosphere in potential space-based food extrusion applications.

BLSS 54, Page 75

Biofiltration of an Advanced Life Support Ersatz Gas Mixture

Wei Li, Robert M. Cowan, John A. Hogan, Peter F. Strom, and Chelsea Brook

NJ-NSCORT and the Department of Environmental Sciences
Cook College and New Jersey Agricultural Experiment Station
Rutgers, The State University of New Jersey

Rutgers, The State University of New Jersey
Department of Environmental Sciences
14 College Farm Road
New Brunswick NJ 08901-8551
Tel: 732-932-6684
Fax: 732-932-8644
E-mail:  weili@eden.rutgers.edu

Biofilters are able to effectively treat a broad range of contaminants simultaneously, and are therefore currently being investigated as a potential biological trace air contaminant control technology for Advanced Life Support (ALS) systems. Research from this laboratory had previously focused on separately treating ammonia and ethylene, as each pose a unique challenge to the biofiltration process. Although both compounds have been successfully treated, actual ALS cabin atmospheres will contain a extensive number of dissimilar volatile organic and inorganic compounds. The interactions of these compounds could impart both beneficial and detrimental effects to biofilter systems.

This project represents the next step in more accurately assessing and developing biofiltration for ALS systems as it employed an ersatz mixture comprised of 16 compounds commonly observed in ALS atmospheres. They include: benzene; toluene; benzaldehyde; isoprene; methylene chloride; 1-butanol; ethanol; methanol; phenol; ethylene; methane; carbon monoxide; methyl ethyl ketone; ammonia; acetone; and ethyl acetate.

A closed aqueous reactor was designed and fabricated that allowed a continuous introduction of the ersatz mixture in order to develop the appropriate microbial cultures. Using respirometric techniques, it was determined that microbial enrichments have been developed that successfully degrade each of the 16 compounds. The biodegradation stoichiometry and kinetics of each compound was quantified.

 Currently, a biofiltration system using 14L reactors is being developed that allows the constant introduction of the ersatz gas contaminant mixture, and preliminary studies are being conducted. It is anticipated that the results from these studies will aid in the investigation into even more complex mixtures, such as those encountered in biological waste treatment system off gases.

BLSS 55, Page 76

Crop Production Area Requirements Based on Optimized Menus for Advanced Life Support

Geoffrey R. Cloutier and Mike A. Dixon
University of Guelph, Department of Plant Agriculture

Jean B. Hunter and Ammar Olabi
Cornell University, Department of Food Science

Christophe Lasseur
European Space Agency - ESTEC

Ideally, the majority of crops needed for the dietary fulfillment of crew in a long-term manned space mission (i.e. Mars) would be produced in-situ. This is the basis of the bioregenerative approach to life support. To calculate the total crop production area required to meet crew dietary demands it is necessary to define the cultural requirements of the full compliment of candidate crops used as ingredients in menus.

Design of the Planetary Life Support Systems Test Complex's Biomass Production Chambers (BPCs) has provision for a total crop production area of 82 m2 (in one of the BPCs; Barta et al, 1999). Although the BPC is expected to produce major staple crops (wheat, rice, white potato, sweet potato, soybean, peanut and dry bean) and fresh vegetables (lettuce, cabbage, spinach, chard, carrot, radish and onion) it is unknown whether the production area would be sufficient to meet the demands of optimized menus. Other estimates of crop production area have been provided by Drysdale et al (1994). This earlier work determined the baseline diet for a single person per day and used productivity data for lettuce, potato soybean and wheat to estimate production areas. The total production area was estimated to be 73 m2. These estimates were not based on the results of menu optimization studies. Clearly, there is a need to establish estimates of production area requirements based on the dietary needs of crew and reliable crop productivity data so that human integration trials can be sized appropriately.

Optimized menus for a bioregenerative life support system have been developed in this work based on measures of crop productivity, food item acceptability, menu diversity, and nutritional requirements of crew. Crop specific biomass requirements were calculated from menu recipe demands while accounting for food processing and preparation losses. Cost of the bioregenerative food system is estimated at is 232.8 Kg per menu cycle or 7.18 Kg ESM crew-1 day-1, including agricultural waste processing costs. This number is high compared to the ISS (non-regenerative) system but reductions in ESM may be achieved through intensive crop specific enhancements in productivity. Crop production areas required to meet a 10-day menu cycle for a crew of 6 total 277.9 m2. This number assumes continuous production and will therefore meet menu demands in perpetuity.

BLSS 56, Page 77

Organic Carbon and Nitrogen Removals in Immobilized Cell Packed Bed Bioreactors

M. Nashashibi-Rabah, C. Christodoulatos, and G. Korfiatis

NJ-NSCORT, Center for Environmental Engineering, Stevens Institute of Technology
Center for Environmental Engineering
Stevens Institute of Technology
Castle Point on the Hudson
Hoboken, NJ 07030
Tel: (201) 216 5675
Fax: (201) 216 8303
E-mail: christod@stevens-tech.edu

Biological processing of grey water in space presents serious challenges, stemming mainly from microgravity conditions. The major problem associated with microgravity is phase separation. To overcome the solid-liquid phase sparation problem, immobilized cell packed bed (ICPB) bioreactors are being used to treat synthetic grey water. Silicone cappilaries are being tested for pressurized oxygen delivery to minimize the production of bubbles and overcome the gas-liquid phase separation problem.

Two aerobic ICPB bioreactor-systems have been developed and are operated with synthetic grey water. One is operated under ambient conditions and the other is pressurized. The ambient system consists of three packed-bed columns: one for organic carbon removal and organic nitrogen reduction to ammonia and two for nitrification. Grey water is pumped to the organic carbon removal column, the effluent of which is pumped to the two-nitrification columns that are in parallel. One nitrification column consists of plastic packing media and the second consists of marble chips in addition to plastic packing media. The pressurized reactor consists of an ICPB column and oxygen transfer chamber, where recirculated water from the ICPB column gets saturated with oxygen using silicone membranes. The whole system is kept under pressure (currently at 50 psig).

High organic carbon removal and organic nitrogen reduction rates (> 95%) are achieved in the organic carbon removal column of the control reactor, with low hydraulic retention times (HRT). The HRT in the first column is approximately 4 hours. The operation of the two nitrification packed-bed columns has just started. The nitrifying bacteria are developing and some nitrification is taking place. No nitrification is achieved in the first column due to the high organic loading rate.

Due to the elevated operating pressure, high dissolved oxygen concentration is maintained in the pressurized reactor system. The organic carbon removal rate is as high as 90% with a HRT of approximately 8 hours.

Both reactor systems (the ambient and the pressurized) have been operating for 2 years approximately and the total suspended solids concentration in the effluent of each reactor system is as low as 20 mg/L.

BLSS 57, Page 78

Monitoring Volatile Organic Compounds from Crops Grown in NASA's Biomass Production Chamber

Barbara V. Peterson1, Raymond M. Wheeler 2, and Gary W. Stutte1,

1Dynamac 2NASA, Kennedy Space Center, Florida

Kennedy Space Center, Florida 32899
Tel: (407) 853-3281
FAX: (407) 853-2939
E-mail: barbara.peterson-1@ksc.nasa.gov

In a closed environment, such as a space craft, odor generation and/or the presence of potentially harmful compounds is a serious concern. Monitoring of ethylene production was conducted throughout crop development for lettuce, potato, rice, soybean, tomato, and wheat in NASA's Advanced Life Support, Biomass Production Chamber at Kennedy Space Center. Volatile organic compounds have been quantified for potato, rice, soybean, tomato, and wheat.

Ethylene was monitored by gas chromatography with a photoionization detector, GC/PID. A 0.5-mL sample loop allowed for automatic, daily sampling. A regime was established to sample every six hours with a daily calibration of the instrument. Detectable limits of 5 ppb were determined.

Identification of volatile organic compounds and concentration levels present in ambient air of the plant growth chamber was determined by gas chromatography with mass selective detector, GC/MS. Air samples were collected with Summa® polished canisters designed for air analysis. Efforts have been made to determine biogenic and/or anthropomorphic origin of each organic compound.

Hexane, chloroform, acetone, acetonitrile, and ethanol were contaminants from laboratory activities. Siloxane compounds (hexamethylcyclotrisiloxane and octamethylcyclotetrasiloxane) were off-gassing products from silicone sealants. 2-Butanone (methylethylketone or MEK) and tetrahydrofuran were traced to adhesives. Contributions of low levels of toluene, benzene, halocarbons, and hydrocarbons were attributed to materials used in or in close proximity of the chamber. Biogenic components included alpha pinene, beta pinene, camphene, ethylene, phellandrene, alpha terpinene, gamma terpinene, 1-hexadecanol, 2-hexen-1-ol acetate, heptanal, hexanal, p-cymene, 2-ethyl furan, nonanal, limonene, alpha-terpineol, isoprene, dimethyl disulfide, acetaldehyde, and benzaldehyde. Carbon disulfide, acetone, and ethanol can also be attributed biogenic as well as anthropogenic origins. Either plants or microorganisms may contribute thiobismethane (also known as methylsulfide, dimethylsulfide, or DMS).

BLSS 58, Page 79

Design of a Biofilter for Ammonia Removal

James F. Russell 1 and John Hogan 2

 1Department of Chemical and Biochemical Engineering, Rutgers, the State University of N.J.
Address: 93 Longfield Ct. East Brunswick, NJ 08816
Tel: 732.967.9347
Email: mist@eden.rutgers.edu
 2Department of Environmental Science, Rutgers, the State University of N.J.

Biofiltration is a potentially effective trace contaminant control system for Advanced Life Support Systems (ALSS) as it is has a high removal capacity and is an energy efficient system when appropriately designed and operated. The Waste Processing and Resource Recovery team of the New Jersey - NASA Specialized Center of Research and Training (NJ-NSCORT) is investigating the use of biofilters for a variety of ALSS pertinent compounds. In particular, the compound ammonia (NH3) poses a challenge to successful biofilter operation as the biodegradation environment dynamically changes due to the accumulation of ammonia and its metabolic (biotransformation) products. This accumulation negatively affects the quality of the microbial environment, eventually limiting or eliminating the desired biological activity. This paper covers the development of a conceptual design of a nitrifying biofilter based upon experimental data and a mathematical biofilter simulation. It is expected that this conceptual design combined with the biofilter simulation will provide a sound basis for use in ALS system studies of biofilter design and control.

BLSS 59, Page 80

Pretreatment Design for Resource Recovery from Inedible Biomass

Michael J. Selig1, Theresa G. Cargioli1, Jean B. Hunter1 and Catherine Hoang 2

1Agricultural and Biological Engineering Department, Cornell University
 2NASA SHARP-Plus Program

In a bioregenerative life support system, a balanced mix of crop plants produces roughly 50% edible and 50% inedible biomass. The inedible fraction is a renewable source of fixed carbon and energy which is chemically very similar to edible biomass. Inedible biomass may be converted to glucose by hydrolysis of the cellulosic fraction, or a mixed sugar stream suitable as a fermentation substrate by hydrolysis of the combined cellulose and hemicellulose fractions. However, hydrolysis processes require substrate pretreatment: leaching to recover soluble minerals for use as plant nutrients, and oxidation to break down lignin and provide the hydrolytic enzymes with access to the carbohydrates. Standard laboratory leaching and oxidation processes demand large amounts of water and alkali, and require long treatment periods.

Alkaline peroxide pretreatment and hot water leaching were redesigned for improved efficiency based on mass transfer and kinetic analyses. The revised process, described in the presentation, uses 50% less water, 75% less alkali and 65% less time than the original process for the same hydrolytic efficiency.

BLSS 60, Page 81

Nitrogen Limitation and Effect of Ammonium or Nitrate as Nitrogen Sources on the Removal of 1 ppm Ethylene in Air Using Biofiltration

Jyoti A. Tambwekar, John A. Hogan, Robert M. Cowan, and Peter F. Strom

NJ-NSCORT and Department of Environmental Sciences
Cook College and New Jersey Agricultural Experiment Station
Rutgers, The State University of New Jersey

Rutgers, The State University of New Jersey
Department of Environmental Sciences
14 College Farm Road
New Brunswick NJ 08901-8551
Tel: 732-932-6684
Fax: 732-932-8644
E-mail: jat@eden.rutgers.edu

Ethylene (C2H4) gas partitions poorly into water and its accumulation in closed environments can adversely affect plant growth and development at extremely low concentrations. Our previous biofiltration studies using perlite have treated C2H4 concentrations of 1 and 10 parts per million (ppm) to a target value of <40 parts per billion (ppb). Both systems maintained exit concentrations <40ppb for only ~14 days, after which gradual increases were observed. One possible factor limiting system performance is low nitrogen (N) availability. The objective of this study was to determine the effect of variable initial N loading and form (ammonium, NH4+, vs. nitrate, NO3-) on microbial C2H4 removal. Four 13L perlite biofilters were challenged with 1ppm C2H4. Reactors 1 and 2 received 0.032 and 0.333 mg NO3--N/g dry wt. perlite, respectively, and reactors 3 and 4 received 0.05 and 0.454 mg NH4+-N/ g dry wt. perlite, respectively. Reactors 1-4 were terminated on days 89, 110, 88 and 109, with lowest observed exit concentrations of 88, 70, 30, and 161 ppb, respectively. Results indicate that both NH4+ and NO3- were utilized as N sources, and that the lower N loadings did not appear to limit total C2H4 removal. However, a comparison of the stratified C2H4 removal and inorganic N data between reactors 1 and 2 suggests that localized N limitation occurred in reactor 1. Only reactor 3 removed C2H4 to <40ppb (for a 12-day period), possibly indicating a preference forNH4+ as the N source and/or additional removal via cometabolism of C2H4 by nitrifiers. The increased extent of nitrification in reactor 4, as evidenced by a substantial drop in matrix pH, could account for decreased C2H4 removal.

BLSS 61, Page 82

Periodic Flow and its Effect on the Mass Transfer of Species

Aaron M. Thomas1 and Ranga Narayanan

University of Florida, Department of Chemical Engineering

1University of Florida
Department of Chemical Engineering Room 227
Gainesville, FL 32611
Tel: (352)392-6209
Fax: (352)392-6219
E-mail: athomas@che.ufl.edu

Separation of CO2 from air is important in maintaining a self-supporting human environment. Using simple periodic flow in a system is a purely mechanical means to aid in the separation of dilute species from a carrier such as CO2 from air. Calculations for periodic flow between two flat plates show a great enhancement of the total mass transfer of a dilute species over pure molecular diffusion. If two dilute species are introduced in the mixture such that one has a higher diffusion coefficient making it the faster diffuser, the total mass transfer of the faster diffuser may have a higher, lower, or the same total mass transfer as the slower diffusing species. Because of the difference in total mass transfer for each dilute species, a separation can be achieved using this purely mechanical means. These findings will be presented along with an explanation as to why it occurs and its relationship to the diffusivities of each species, the periodicity of the system, and the kinematic viscosity of the carrier fluid. Further, the effect of eccentricity on the mass transfer and separation will also be discussed.

BLSS 62, Page 83

High Efficiency, Stable Liquid Membranes for Gas Capture

Dr. Michael Trachtenberg

The Sapient's Institute
Rutgers University/Cook college
New Brunswick, NJ

Liquid membrane systems are a promising technology that could greatly reduce the costs of separation, especially of gases with special reference to carbon dioxide. Despite 30 years of research these designs have not been optimized nor have they been stabilized to the level needed to function in a commercial environment. The parameters that control the three key functions - stability, solubility and diffusivity - interact non-linearly and multidimensionally. The object of this research is to characterize and optimize these parameters, to construct and test optimized designs and to demonstrate their long-term stability coupled with high flux and selectivity. One consequence of this effort will be derivation of sensitivity relationships that bound the operating conditions and are needed to realize operational stability. Another goal is to establish principles for the construction of selected liquid membranes specific to other gases, liquids and mixtures. This approach is based, in part, on a failure mode analysis we have constructed of such systems. These efforts are targeted at introducing liquid membranes into wide commercial and industrial use.