Life Sciences Commons^™

Life Support: Long Term Storage Of Solid Waste In An Enclosed Membrane System, Emmy O. Trieu, Michael Flynn, Rocco Mancinelli

STAR Program Research Presentations

In deep space missions, maintaining life support is of the utmost priority. In such a closed system, human waste must be stored and treated. Simulated feces (ersatz) will be inoculated with microbes representing normal fecal flora, mixed with urine brine and shredded refuse of products typically used in space missions. Composting methods often use alternating layers of waste with scraps of carboniferous materials (finely shredded refuse). By preparing membrane bags with a homogenized ersatz and carboniferous refuse mixture and membrane bags with alternating layers of ersatz and carboniferous refuse, it may be possible to monitor anaerobic thermophillic digestion of the …

Testing Compounds As Sole Carbon Sources Of Strains Isolated From The Hot Lake Phototrophic Mat, Lyzbeth Becerra, Stephen Lindemann

STAR Program Research Presentations

Hot Lake is a meromictic, epsomitic lake. It has a phototrophic microbial mat that reassembles every year. The mat community is subjected to large fluctuations of salinity and solar irradiance. PNNL is interested in studying how these communities respond to the fluctuating environment conditions. To date, 70 isolates have been obtained from Hot Lake with the intention of characterizing their physiology to gain a better understanding of how they are naturally functioning in the Hot Lake mat community. I tested eight of these isolates in media designed to mimic the chemistry of Hot Lake with a selection of sugars, amino …

Characterization Of Bacillus Bacterial Strains; Optimum Growth Temperature, Proteolytic And Lipolytic Activity, Jamie Anne Boring

STAR Program Research Presentations

Characterization of Bacillus bacterial strains is an important step in identifying and removing biofilms contaminating processing equipment. These biofilms lead to large amounts of spores in the final product. Strains that produce spoilage enzymes cause off-flavors, structural defects and reduced shelf life of milk products. Using four treatments, we determined the best growth protocol for each strain to use in future experiments. Treatment 1: 80 ^o C heat shock and 32 ^o C 24hr incubation, Treatment 2: 80^o C/ 55 ^o C, Treatment 3: 100 ^o C/ 32 ^o C, Treatment 4: 100 ^o C/ 55 ^o C. Our …

Optimizing Electrode Design For Microbial Fuel Cells Used For Wastewater Treatment, Lindsay Nichols, John A. Hogan

STAR Program Research Presentations

Microbial fuel cells (MFC) utilize bacteria to generate an electrical current that can be used in the decomposition of sludge and human urine. In a MFC there is an anode (for oxidation of organic compounds), cathode (reduction of oxygen or carbon dioxide), and a proton exchange membrane (PEM, allows protons to migrate); reduction-oxidation reactions between the anode and cathode produce a measurable current. Bacteria that are found in sludge can be used to produce electrons in a voltaic cell, but optimizing conditions for harnessing the energy is crucial to making a MFC efficient. Research has shown that the ratios of …

Detection Of Viable Microorganisms Using Propidium Monoazide, Erik J. Mcfarland, Adrian Ponce Dr.

STAR Program Research Presentations

Propidium monoazide (PMA) is a molecular tool used to assess viability of microorganisms. Currently, PMA is thought to discern viability through membrane permeability; PMA enters only membrane compromised cells, irreversibly crosslinks to theirDNAand precipitates theDNAout of solution, preventing it from being amplified during polymerase chain reaction (PCR). Using PMA on a sample of live and dead microorganisms results in only theDNAof living organisms being amplified and identified. Therefore, a comparison ofPCRresults with and without PMA allows one to determine the live fraction and total population, respectively.

Current literature provides conflicting evidence as to the effectiveness of the technique. Our research …