Microbial extremophiles from the 2008 Schirmacher Oasis Expedition: preliminary results

Hoover, Richard B.; Pikuta, Elena V.; Townsend, Alisa; Anthony, James R.; Guisler, Melissa; Mcdaniel, J. D.; Bej, Asim K.; Storrie-Lombardi, Michael C.

doi:10.1117/12.801018

Cited by 5 publications

(4 citation statements)

References 15 publications

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“…such taxa that have not been deeply tested on a possible Mars-like organism yet. Regarding the other dominant strains in the samples, T. byssoidea and N. microscopicum have already been identified at the interesting Mars analogue location of Schirmacher Oasis in Antarctica (Hoover et al 2008) and other terrains (Stojanovic et al 2008;Schmidt et al 2009), and were found to be a possible candidate for Mars analogue research using their adaptation to low temperature and elevated salinity.…”

Section: Resultsmentioning

confidence: 90%

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Results on the survival of cryptobiotic cyanobacteria samples after exposure to Mars-like environmental conditions

Vera

Dulai

Keresztúri³

et al. 2013

International Journal of Astrobiology

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Tests on cyanobacteria communities embedded in cryptobiotic crusts collected in hot and cold deserts on Earth were performed under Mars-like conditions. The simulations were realized as a survey, to find the best samples for future research. During the tests organisms have to resist Mars-like conditions such as atmospheric composition, pressure, variable humidity (saturated and dry conditions) and partly strong UV irradiation. Organisms were tested within their original habitat inside the crust. Nearly half of the cryptobiotic samples from various sites showed survival of a substantial part of their coexisting organisms. The survival in general depended more on the nature of the original habitat and type of the sample than on the different conditions they were exposed to. The best survival was observed in samples from United Arab Emirates (Jebel Ali, 25 km SW of Dubai town) and from Western Australia (near the South edge of Lake Barley), by taxa: Tolypothrix byssoidea, Gloeocapsopsis pleurocapsoides, Nostoc microscopicum, Leptolyngbya or Symploca sp. At both places in salty desert areas members of the Chenopodiaceae family dominated among the higher plants and in the cryptobiotic crust cyanobacterial taxa Tolypothrix was dominant. These organisms were all living in salty locations with dry conditions most of the year. Among them Tolypothrix, Gloeocapsopsis and Symploca sp. were tested in Mars simulation chambers for the first time. The results suggest that extremophiles should be tested with taken into account the context of their original microenvironment, and also the importance to analyse communities of microbes beside single organisms.

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Section: Resultsmentioning

confidence: 90%

“…Regarding the other dominant strains in the samples, T. byssoidea and N. microscopicum have already been identified at the interesting Mars analogue location of Schirmacher Oasis in Antarctica (Hoover et al . 2008) and other terrains (Stojanovic et al . 2008; Schmidt et al .…”

Section: Resultsmentioning

confidence: 99%

Results on the survival of cryptobiotic cyanobacteria samples after exposure to Mars-like environmental conditions

Vera

Dulai

Keresztúri³

et al. 2013

International Journal of Astrobiology

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“…The Hach Hydrolab was used to measure temperature, dissolved oxygen, Eh, pH, and conductivity at each collection site. 16 The data on water temperature, pH, and dissolved oxygen as a function of depth in the water column at the deep anoxic trough sampling site (S 71 o 21' 21.5"; E 013 o 25' 37.8") was obtained on the Tawani International Expedition on November 22, 2008, and it is shown in Figure 2. These results were in relatively good agreement with the Wand's measurements 14,15; although, the maximal pH (10.2) was notably lower than their measurement of pH maximum 12.1.…”

Section: Lake Unterseementioning

confidence: 99%

Anaerobic psychrophiles from Lake Zub and Lake Untersee, Antarctica

et al. 2009

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The study of samples from Antarctica 2008 and 2009 expeditions organized and successfully conducted by Richard Hoover led to the isolation of diverse anaerobic strains with psychrotolerant and psychrophilic physiology. Due to the fact that Lake Untersee has never been subject to microbiological study, this work with the samples has significant and pioneering impact to the knowledge about the biology of this unique ecosystem. Also, the astrobiological significance for the study of these ecosystems is based on new findings of ice covered water systems on other bodies of our solar system.Anaerobic psychrotolerant strain LZ-22 was isolated from a frozen sample of green moss with soils around the rhizosphere collected near Lake Zub in Antarctica. Morphology of strain LZ-22 was observed to be motile, rod shaped and spore-forming cells with sizes 1 x 5-10 µm. This new isolate is a mesophile with the maximum temperature of growth at 40°C. Strain LZ-22 is able to live on media without NaCl and in media with up to 7 % (w/v) NaCl. It is catalase negative and grows only on sugars with the best growth rate being on lactose. The strain is a neutrophile and grows between pH 5 and 9.0 with the optimum at 7.8.Another two strains UL7-96mG and LU-96m7P were isolated from deep water samples of Lake Untersee. Proteolytic strain LU-96m7P had a truly psychrophilic nature and refused to grow at room temperature. Sugarlytic strain UL7-96mG was found to be psychrotolerant, but its rate of growth at 3°C was very high compared with other mesophiles.Two homoacetogenic psychrophilic strains A7AC-96m and AC-DS7 were isolated and purified from samples of Lake Untersee; both of them are able to grow chemolithotrophically on H 2+CO2 . In the presence of lactate, these strains are able to grow only at 0-18 o C, and growth at 22 o C was observed only with yeast extract stimulation. In this paper, physiological and morphological characteristics of novel psychrophilic and psychrotolerant isolates from Antarctica 2008 and 2009 expeditions will be discussed.

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“…It was carried out by five members of the international team to the Schirmacher Oasis and Lake Untersee, Antarctica. (Hoover et al, 2008). A number of anaerobic microbial cultures were obtained.…”

Section: Tawani International Antarctica Expeditionsmentioning

confidence: 99%