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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1971

Microorganism sample device

Device, based on gel-impingement technique, collects microorganism specimens from circulating air streams. Device is useful to air pollution studies involving the collection of airborne microbial specimens.

Reed, L. L.↗
NASA NTRS1972

Enhanced degradation of aluminum metal in the presence of selected microorganisms

Experiments were conducted to determine the effects of microorganisms, substrates, pressures, humidities, and oxygen concentrations upon aluminum corrosion. In addition, the effects of microbes upon coated and treated aluminum were examined and an attempt to correlate aluminum in solution with degradation of the samples was undertaken. The organisms, humidities, oxygen levels, and substrates all played a major role in the corrosion of aluminum. Quantitation of aluminum losses indicated that the total metal losses from inoculated samples were significantly greater than those of the uninoculated samples.

Tennyson, J. M.↗
NASA NTRS1971

The Effect of Temperature on the Survival of Microorganisms in a Deep Space Vacuum

A space molecular sink research facility (Molsink) was used to evaluate the ability of microorganisms to survive the vacuum of outer space. This facility could be programmed to simulate flight spacecraft vacuum environments at pressures in the .1 nanotorr range and thermal gradients (30 to 60 C) closely associated to surface temperatures of inflight spacecraft. Initial populations of Staphylococcus epidermidis and a Micrococcus sp. were reduced approximately 1 log while exposed to -105 and 34 C, and approximately 2 logs while exposed to 59 C for 14 days in the vacuum environment. Spores of Bacillus subtilis var. niger were less affected by the environment. Initial spore populations were reduced 0.2, 0.3, and 0.8 log during the 14-day vacuum exposure at -124, 34, and 59 C, respectively.

Hagen, C. A.↗
NASA NTRS1972

Resistance of soil microorganisms to starvation.

Most groups of soil microorganisms died when exposed to prolonged starvation in a carbon-free solution, but the relative abundance of Bacillus and actinomycetes increased with time. Certain nonspore-forming bacteria also persisted. The ability of individual soil isolates to endure starvation in solution was not correlated with their glycogen content or rate of endogenous respiration. However, cells of the resistant populations were rich in poly-beta-hydroxybutyrate, whereas the starvation-susceptible bacteria generally contained little of this substance. Poly-beta-hydroxybutyrate was used rapidly in cells deprived of exogenous sources of carbon.

Chen, M.↗
NASA NTRS1974

Recovery of medically important microorganisms from Apollo astronauts

Microbiological samples were obtained from the crewmembers of the Apollo 13, 14, 15, 16, and 17 spaceflights. These specimens were analyzed for the presence of medically important microorganisms with Staphylococcus aureus, Pseudomonas aeruginosa, Tricophyton mentagrophytes, Tricophyton rubrum, and Candida albicans being discussed in detail. Preflight isolation of crewmembers was found to coincide with a complete absence of inflight disease events and is recommended for future spaceflights. No autoinfection response (microbial shock) occurred after any of the reported spaceflights.

Taylor, G. R.↗
NASA NTRS1978

Assessment of free-living nitrogen fixing microorganisms for commercial nitrogen fixation

Ammonia production by Klebsiella pneumoniae is not economical with present strains and improving nitrogen fixation to its theoretical limits in this organism is not sufficient to achieve economic viability. Because the value of both the hydrogen produced by this organism and the methane value of the carbon source required greatly exceed the value of the ammonia formed, ammonia (fixed nitrogen) should be considered the by-product. The production of hydrogen by KLEBSIELLA or other anaerobic nitrogen fixers should receive additional study, because the activity of nitrogenase offers a significant improvement in hydrogen production. The production of fixed nitrogen in the form of cell mass by Azotobacter is also uneconomical and the methane value of the carbon substrate exceeds the value of the nitrogen fixed. Parametric studies indicate that as efficiencies approach the theoretical limits the economics may become competitive. The use of nif-derepressed microorganisms, particularly blue-green algae, may have significant potential for in situ fertilization in the environment.

Stokes, B. O.↗