Browsing by Author "Spencer, LaShelle E."

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Microorganism Utilization for Synthetic Milk Production
(44th International Conference on Environmental Systems, 2014-07-13) Morford, Megan A.; Khodadad, Christina L.; Spencer, LaShelle E.; Richards, Jeffrey T.; Strayer, Richard F.; Caro, Janicce L.; Hummerick, Mary E.; Birmele, Michele N.; Wheeler, Raymond M.
A desired architecture for long duration spaceflight, such as aboard the International Space Station (ISS) or for future missions to Mars, is to provide a supply of fresh food crops for the astronauts. However, some crops can create a high proportion of inedible plant waste. The main goal of this project was to produce the components of milk (sugar, lipid, protein) from inedible plant waste by utilizing microorganisms (fungi, yeast, bacteria). Of particular interest was utilizing the valuable polysaccharide, cellulose, found in plant waste, to naturally fuel- through microorganism cellular metabolism- the creation of sugar (glucose), lipid (milk fat), and protein (casein) to produce a synthetic edible food product. Environmental conditions such as pH, temperature, carbon source, aeration, and choice microorganisms were optimized in the laboratory and the desired end-products, sugars and lipids, were analyzed. Trichoderma reesei, a known cellulolytic fungus, was utilized to drive the production of glucose, with the intent that the produced glucose would serve as the carbon source for milk fat production and be a substitute for the milk sugar lactose. Lipid production would be carried out by Rhodosporidium toruloides, yeast known to accumulate those lipids that are typically found in milk fat. Results showed that glucose and total lipid content were below what was expected during this phase of experimentation. In addition, individual analysis of six fatty acids revealed that the percentage of each fatty acid was lower than naturally produced bovine milk. Overall, this research indicates that microorganisms could be utilized to breakdown inedible solid waste to produce useable products.
A novel ion exchange system to purify mixed ISS waste water brines for chemical production and enhanced water recovery
(44th International Conference on Environmental Systems, 2014-07-13) Lunn, Griffin M.; Spencer, LaShelle E.; Ruby, Anna Maria J.; McCaskill, Andrew
The International Space Station water recovery system produces a sizable portion of waste water brine. This brine is highly toxic and contains a significant volume of water. With new biological techniques that do not require waste water chemical pretreatment, the resulting brine would be chromium-free, nitrate rich, and could be used for fertilizer recovery in future plant systems. Using a system of ion exchange resins may remove hardness, sulfate, phosphate and nitrate from these brines leaving only sodium and potassium chloride. At this point modern chlor-alkali cells can be utilized to produce a low salt stream as well as an acid and base stream. The first stream (low salt) can be used to gain higher water recovery through recycle to the water separation stage while the last two streams can be used to regenerate the ion exchange beds used here, as well as other ion exchange beds in the ISS. Conveniently these waste products from ion exchange regeneration would be suitable as plant fertilizer. In this report the performance of state of the art resins designed for high selectivity of target ions under brine conditions was determined. Using ersatz ISS waste water we can evaluate the performance of specific resins and calculate mass balances to determine resin effectiveness and process viability. If this system is feasible then we will be one step closer to closed loop environmental control and life support systems (ECLSS) for current or future applications.
Selection of Leafy Green Vegetable Varieties for a Pick-and- Eat Diet Supplement on ISS
(45th International Conference on Environmental Systems, 2015-07-12) Massa, Gioia D.; Wheeler, Raymond M.; Stutte, Gary W.; Richards, Jeffrey T.; Spencer, LaShelle E.; Hummerick, Mary E.; Douglas, Grace L.; Sirmons, Takiyah
Several varieties of leafy vegetables were evaluated with the goal of selecting those with the best growth, nutrition, and organoleptic acceptability for ISS. Candidate species were narrowed to commercially available cultivars with desirable growth attributes for space (e.g., short stature and rapid growth). Seeds were germinated in controlled environment chambers under conditions similar to what might be found in the Veggie plant growth chamber on ISS. Eight varieties of leafy greens were grown: ‘Tyee’ spinach , ‘Flamingo’ spinach , ‘Outredgeous’ Red Romaine lettuce , ‘Waldmann’s Dark Green’ leaf lettuce, ‘Bull’s Blood’ beet, ‘Rhubarb’ Swiss chard, ‘Tokyo Bekana’ Chinese cabbage, and Mizuna. Plants were harvested at maturity and biometric data on plant height, diameter, chlorophyll content, and fresh mass were obtained. Tissue was ground and extractions were performed to determine the tissue elemental content of Potassium (K), Magnesium (Mg), Calcium (Ca) and Iron (Fe). Following the biometric/elemental evaluation, four of the eight varieties were tested further for levels of anthocyanins, antioxidant (ORAC-fluorescein) capacity, lutein, zeaxanthin, and Vitamin K. For sensory evaluation, ‘Outredgeous’ lettuce, Swiss chard, Chinese cabbage, and Mizuna plants were grown, harvested when mature, packaged under refrigerated conditions, and sent to the JSC Space Food Systems Laboratory. Tasters evaluated overall acceptability, appearance, color intensity, bitterness, flavor, texture, crispness and tenderness. All varieties received acceptable scores with overall ratings greater than 6 on a 9-point hedonic scale. Chinese cabbage was the highest rated, followed by Mizuna, ‘Outredgeous’ lettuce, and Swiss chard. Based on our results, the selected varieties of Chinese cabbage, lettuce, Swiss chard and Mizuna seem suitable for a pick-and-eat scenario on ISS with a ranking based on all factors analyzed to help establish priority.