Psychrophilic Microorganisms from Areas Associated with the Viking Spacecraft

Foster, Terry; Winans, L.

doi:10.1128/aem.30.4.546-550.1975

Cited by 10 publications

(5 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Fifth, during the Apollo era, a correlation between relaxed sanitation protocols and increased microbial diversity was observed in latter missions (Puleo et al, 1973b). Sixth, many of the microbial species recovered from spacecraft surfaces are aerobic mesophilic species, although facultative anaerobes have been recovered from some vehicles (Foster and Winans, 1975). And seventh, the abundance of sporeforming bacteria (predominantly Bacillus spp.)…”

Section: Introductionmentioning

confidence: 99%

A Lunar Microbial Survival Model for Predicting the Forward Contamination of the Moon

Schuerger

Moores²,

Smith

et al. 2019

Astrobiology

View full text Add to dashboard Cite

The surface conditions on the Moon are extremely harsh with high doses of ultraviolet (UV) irradiation (26.8 W $ m-2 UVC/UVB), wide temperature extremes (-171°C to 140°C), low pressure (10-10 Pa), and high levels of ionizing radiation. External spacecraft surfaces on the Moon are generally >100°C during daylight hours and can reach as high as 140°C at local noon. A Lunar Microbial Survival (LMS) model was developed that estimated (1) the total viable bioburden of all spacecraft landed on the Moon as *4.57 • 10 10 microbial cells/ spores at contact, (2) the inactivation kinetics of Bacillus subtilis spores to vacuum as approaching-2 logs per 2107 days, (3) the inactivation of spores on external surfaces due to concomitant low-pressure and hightemperature conditions as-6 logs per 8 h for local noon conditions, and (4) the ionizing radiation by solar wind particles as approaching-3 logs per lunation on external surfaces only. When the biocidal factors of solar UV, vacuum, high-temperature, and ionizing radiation were combined into an integrated LMS model, a theoretical-2479 log reduction in viable bioburden was predicted for external spacecraft surfaces per lunation at the equator. Results indicate that external surfaces of landed or crashed spacecraft are unlikely to harbor viable spores after only one lunation, that shallow internal surfaces will be sterilized due to the interactive effects of vacuum and thermal cycling from solar irradiation, and that deep internal surfaces would be affected only by vacuum with a degradation rate of-0.02 logs per lunation.

show abstract

Section: Introductionmentioning

confidence: 99%

A Lunar Microbial Survival Model for Predicting the Forward Contamination of the Moon

Schuerger

Moores²,

Smith

et al. 2019

Astrobiology

View full text Add to dashboard Cite

show abstract

“…The observation of high (per)chlorate tolerance in salinotolerant bacteria demonstrates that terrestrial microbes are capable of growing at concentrations of (per)chlorate salts found in Mars soils. However, one of the most likely sources of bacteria that contaminate spacecraft is common oligosaline soil from around the SAF (Foster & Winans 1975; Puleo et al 1977). Common soils appear to harbour bacteria capable of growing at relatively high concentrations of salts and this is a concern for forward planetary protection (Echigo et al 2005; Chen et al 2010).…”

Section: Discussionmentioning

confidence: 99%

Bacterial growth tolerance to concentrations of chlorate and perchlorate salts relevant to Mars

Soudi

Farhat

Chen

et al. 2016

International Journal of Astrobiology

View full text Add to dashboard Cite

The Phoenix lander at Mars polar cap found appreciable levels of (per)chlorate salts, a mixture of perchlorate and chlorate salts of Ca, Fe, Mg and Na at levels of ~0.6% in regolith. These salts are highly hygroscopic and can form saturated brines through deliquescence, likely producing aqueous solutions with very low freezing points on Mars. To support planetary protection efforts, we have measured bacterial growth tolerance to (per)chlorate salts. Existing bacterial isolates from the Great Salt Plains of Oklahoma (NaCl-rich) and Hot Lake in Washington (MgSO4-rich) were tested in high concentrations of Mg, K and Na salts of chlorate and perchlorate. Strong growth was observed with nearly all of these salinotolerant isolates at 1% (~0.1 M) (per)chlorate salts, similar to concentrations observed in bulk soils on Mars. Growth in perchlorate salts was observed at concentrations of at least 10% (~1.0 M). Greater tolerance was observed for chlorate salts, where growth was observed to 2.75 M (>25%). Tolerance to K salts was greatest, followed by Mg salts and then Na salts. Tolerances varied among isolates, even among those within the same phylogenetic clade. Tolerant bacteria included genera that also are found in spacecraft assembly facilities. Substantial microbial tolerance to (per)chlorate salts is a concern for planetary protection since tolerant microbes contaminating spacecraft would have a greater chance for survival and proliferation, despite the harsh chemical conditions found near the surface of Mars.

show abstract

“…Extensive studies of the microbial populations in SAFs have been performed previously using cultivation (Favero et al . 1968; Favero 1971; Foster & Winans 1975; Puleo et al . 1977; Stieglmeier et al .…”

Section: Introductionmentioning

confidence: 99%

Molecular and phenetic characterization of the bacterial assemblage of Hot Lake, WA, an environment with high concentrations of magnesium sulphate, and its relevance to Mars

Kilmer

Eberl

Cunderla

et al. 2014

International Journal of Astrobiology

View full text Add to dashboard Cite

Hot Lake (Oroville, WA) is an athalassohaline epsomite lake that can have precipitating concentrations of MgSO4 salts, mainly epsomite. Little biotic study has been done on epsomite lakes and it was unclear whether microbes isolated from epsomite lakes and their margins would fall within recognized halotolerant genera, common soil genera, or novel phyla. Our initial study cultivated and characterized epsotolerant bacteria from the lake and its margins. Approximately 100 aerobic heterotrophic microbial isolates were obtained by repetitive streak-plating in high-salt media including either 10% NaCl or 2 M MgSO4. The collected isolates were all bacteria, nearly evenly divided between Gram-positive and Gram-negative clades, the most abundant genera being Halomonas, Idiomarina, Marinobacter, Marinococcus, Nesterenkonia, Nocardiopsis, and Planococcus. Bacillus, Corynebacterium, Exiguobacterium, Kocuria, and Staphylococcus also were cultured. This initial study included culture-independent community analysis of direct DNA extracts of lake margin soil using PCR-based clone libraries and 16S rRNA gene phylogeny. Clones assigned Gram-positive bacterial clades (70% of total clones) were dominated by sequences related to uncultured actinobacteria. There were abundant Deltaproteobacteria clones related to bacterial sulfur metabolisms and clones of Legionella and Coxiella. These epsomite lake microbial communities seem to be divided between bacteria primarily associated with hyperhaline environments rich in NaCl and salinotolerant relatives of common soil organisms. Archaea appear to be in low abundance and none were isolated, despite near-saturated salinities. Growth of microbes at very high concentrations of magnesium and other sulfates has relevance to planetary protection and life-detection missions to Mars, where scant liquid water may form as deliquescent brines and appear as eutectic liquids.

show abstract

Psychrophilic Microorganisms from Areas Associated with the Viking Spacecraft

Cited by 10 publications

References 6 publications

A Lunar Microbial Survival Model for Predicting the Forward Contamination of the Moon

A Lunar Microbial Survival Model for Predicting the Forward Contamination of the Moon

Bacterial growth tolerance to concentrations of chlorate and perchlorate salts relevant to Mars

Molecular and phenetic characterization of the bacterial assemblage of Hot Lake, WA, an environment with high concentrations of magnesium sulphate, and its relevance to Mars

Contact Info

Product

Resources

About