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Winans, L., Jr.

Publications and source records attributed to Winans, L., Jr..

10 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

Anaerobic utilization of phosphite and hypophosphite by Bacillus sp.

A Bacillus species capable of using phosphite and hypophosphite under anaerobic conditions was isolated from Cape Canaveral soil samples and grown on a glucose-mineral salts medium with phosphate omitted. The optimum hypophosphite concentration was 60 microg/ml, while the optimum phosphite concentration was greater than 1000 microg/ml. P-32-labeled hypophosphite was incorporated into the cell as organic phosphate, and little or no phosphate appeared in the medium when either hypophosphite or phosphite was the phosphorus source. When phosphate was present in the medium, phosphite was not metabolized. When both phosphite and hypophosphite were present, phosphite was used first and then hypophosphite.

Foster, T. L.↗
NASA NTRS1978

Response of terrestrial microorganisms to a simulated Martian environment

Soil samples from Cape Canaveral were subjected to a simulated Martian environment and assayed periodically over 45 days to determine the effect of various environmental parameters on bacterial populations. The simulated environment was based on the most recent available data, prior to the Viking spacecraft, describing Martian conditions and consisted of a pressure of 7 millibars, an atmosphere of 99.9% CO2 and 0.1% O2, a freeze-thaw cycle of -65 C for 16 h and 24 C for 8 h, and variable moisture and nutrients. Reduced pressure had a significant effect, reducing growth under these conditions. Slight variations in gaseous composition of the simulated atmosphere had negligible effect on growth. The freeze-thaw cycle did not inhibit growth, but did result in a slower rate of decline after growth had occurred. Dry samples exhibited no change during the 45-day experiment, indicating that the simulated Martian environment was not toxic to bacterial populations. Psychrotrophic organisms responded more favorably to this environment than mesophiles, although both types exhibited increases of approximately 3 logs in 7 to 14 days when moisture and nutrients were available.

Foster, T. L.↗
NASA NTRS1977

Response of Selected Microorganisms to Experimental Planetary Environments

Results of studies in anaerobic phosphorus metabolism are presented. Specific topics discussed include: (1) anaerobic utilization of PH3; (2) reduction of phosphate or phosphite; (3) isolation of organisms which utilize phosphite or phosphate anaerobically as a final hydrogen acceptor; and (4) the toxicity of PH3 to the organisms. Techniques of anaerobic microbiology associated with space hardware were also studied. These include: (1) the Brewer anaerobe jar/GasPak system; (2) a new procedure to grow aerobes and anaerobes simultaneously; (3) a culture medium to differentiate oblagate from facultative anaerobes; and (4) a procedure to quantitate O2 sensitivity of anaerobes.

Foster, T. L.↗
NASA NTRS1976

Response of selected microorganisms to experimental planetary environments

Results are presented on the anaerobic conversion of phosphite to phosphate. It is demonstrated that in the presence of both phosphite and hypophosphite, the phosphite is the preferred phosphorous source. An investigation in which P-32 labeled hypophosphite was added to the basal medium demonstrates that the labeled hypophosphite was incorporated into the metabolic reactions of the cell. Other data show that as cell growth occurs, the phosphite and/or hypophosphite levels decrease. The Bacillus sp. capable of anaerobic utilization of phosphite was isolated from Cape Canaveral soil samples, and it is partially characterized. Also included are continued investigations of omnitherms. The data presented show that some of these possess significant resistance to the Viking dry-heat cycle, and that they retain their omnithermic characteristic after recovery from the heat cycle. Other physiological characteristics of these isolates are also presented. It is demonstrated that omnitherms can be isolated from Cape Canaveral soil.

Foster, T. L.↗
NASA NTRS1976

Response of selected microorganisms to experimental planetary environments

The anaerobic utilization of phosphite or phosphine and the significance of this conversion to potential contamination of Jupiter were investigated. A sporeforming organism was isolated from Cape Canaveral soil which anaerobically converts hypophosphite to phosphate. This conversion coincides with an increase in turbidity of the culture and with phosphate accumulation in the medium. Investigations of omnitherms (organisms which grow over a broad temperature range, i.e. 3 -55 C were also conducted. The cellular morphology of 28 of these isolates was investigated, and all were demonstrated to be sporeformers. Biochemical characterizations are also presented. Procedures for replicate plating were evaluated, and those results are also presented. The procedures for different replicate-plating techniques are presented, and these are evaluated on the basis of reproducibility, percentage of viable transfer, and ease of use. Standardized procedures for the enumeration of microbial populations from ocean-dredge samples from Cape Canaveral are also presented.

Foster, T. L.↗
NASA NTRS1974

Quantitative ecology and dry-heat resistance of psychrophiles

Microorganisms capable of growth at 7 C were enumerated and isolated from soil samples from the manufacture area (Denver, Colorado) and assembly area (Cape Kennedy, Florida) of the Viking spacecraft. Temperature requirements were determined for these isolates, and those growing at 3 C, but not at 32 C were designated as obligate psychrophiles in this investigation. These were identified to major generic groups, and the population density of obligate psychrophiles from the various groups was determined. Dry heat D-values were found for those spores that demonstrated growth or survival under a simulated Martian environment.

Winans, L., Jr.↗
NASA NTRS1974

A study of psychrophilic organisms isolated from the manufacture and assembly areas of spacecraft to be used in the Viking mission

The ability of psychrophilic microorganisms to grow in some of the environmental conditions suggested for Mars is studied with particular attention given to the effects of moisture and nutrients on growth. Results of growth with the slide culture technique are presented and indicate that this technique can be a rapid and sensitive technique for demonstration of microbial growth under various environmental conditions. Additional soil samples have been obtained from Cape Kennedy, and results of these assays at various low temperatures for psychrophilic populations are presented. The heat resistance of some of the psychrophilic sporeformers have been determined. Psychrophilic organisms were isolated from the teflon ribbons at Cape Kennedy and characterization of these was begun. In addition, heat survivors from the teflon ribbons are being investigated, and partial characterizations of these are presented.

Foster, T. L.↗
NASA NTRS1973

A study of psychrophilic organisms isolated from the manufacture and assembly areas of spacecraft to be used in the Viking mission, 1 January - 30 June 1973

Soil samples from the areas associated with the Viking spacecraft were analyzed for major generic groups of microorganisms and the percentage of obligate psychrophiles. Results are presented which show the distribution of organisms isolated at low temperatures and the methods employed for subjecting samples to simulated Martian conditions. Emphasis is placed on application of these results to the objectives of the quarantine program.

Foster, T. L.↗
NASA NTRS1973

A study of psychrophilic organisms isolated from the manufacture and assembly areas of spacecraft to be used in the Viking mission

The sampling of soils from the manufacture and assembly areas of the Viking spacecraft is reported and the methodology employed in the analysis of these samples for psychrophilic microorganisms, and temperature studies on these organisms is outlined. Results showing the major types of organisms and the percentage of obligate psychrophiles in each sample are given and discussed. Emphasis in all areas is toward application of these results to the objectives of the planetary quarantine program.

Foster, T. L.↗