The study of a sample collected from a wind-made ice sculpture near Lake Podprudnoe, Antarctica led to the isolation of
the psychrotolerant strain ISLP-3. Cells of the new isolate are vibrio-shaped that measure 0.5 x 1.0-3.0 μm in size.
Growth occurs within the temperature range 5-35ºC with the optimum at 22 °C. Salinity range for growth is 0-2 % NaCl
with the optimum at 0.25 %. The new isolate grows within a pH range from 6.0 to 9.5 with the optimum at 7.5. Strain
ISLP-3 is saccharolytic, growing on the following substrates: D-glucose, D-ribose, D-fructose, D-arabinose, maltose,
sucrose, D-trehalose, D-mannose, D-cellobiose, lactose, starch, chitin, triethylamine, N-acetylglucosamine, and urea.
The best growth occurred on D-cellobiose. An environmental sample of pond water near a colony of the endemic
species of African penguins, Spheniscus demersus, was collected in February 2008 and delivered directly to the
Astrobiology laboratory at NSSTC. The microbiological study of this sample led to the isolation of two psychrotolerant
strains ARHSd-7G and ARHSd-9G. Both strains are strictly anaerobic bacteria and are able to grow at high pH and low
temperatures. The cells of strain ARHSd-7G are motile, vibrio-shaped, spore-forming cells. Optimal growth of this strain
occurs at 30 ºC, 3 % NaCl, and pH 8.9. The isolate ARHSd-7G combines sugarlytic and proteolytic metabolisms,
growing on some proteolysis products including peptone and yeast extract and a number of sugars. The second isolate,
ARHSd-9G, exhibits thin, elongated rods that measure 0.4 x 3-5 μm. The cells are motile and spore-forming. Optimal
growth of strain ARHSd-9G occurs at 30 ºC, 1.75 % NaCl, and pH 8.5. The strain ARHSd-9G is sugarlytic, growing
well on substrates such as D-glucose, sucrose, D-cellobiose, maltose, fructose, D-mannose, and trehalose (the only
exception is positive growth on yeast extract). In this report, the physiological and morphological characteristics of the
novel psychrotolerant, alkaliphilic, and neutrophilic isolates from the Antarctica 2008 expedition will be discussed.
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
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<sub>2</sub>+CO<sub>2</sub>. In the presence of lactate, these
strains are able to grow only at 0-18 °C, and growth at 22 °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.
Among the most interesting targets for Astrobiology research are the polar ice caps and the permafrost of Mars and
the ice and liquid water bodies that may lie beneath the frozen crusts of comets, the icy moons of Jupiter (Europa, Io
and Ganymede) and Saturn (Titan and Enceladus). The permanently ice-covered lakes of Antarctica, such as Lake
Vostok and Lake Untersee, provide some of the best terrestrial analogues for these targets. The 2008 International
Tawani Schirmacher Oasis/Lake Untersee Expeditions have been organized to conduct studies of novel microbial
extremophiles and investigate the biodiversity of the glaciers and ice-covered lakes of Dronning Maud Land, East
This paper describes the preliminary analysis of the anaerobic microbial extremophiles isolated from samples
collected during the 2008 International Schirmacher Oasis Antarctica Reconnaissance Expedition. These samples
showed great diversity of psychrophlic and psychrotolerant bacteria. Six new anaerobic strains have been isolated in
pure cultures and partially characterized. Two of them (strains ARHSd-7G and ARHSd-9G) were isolated from a
small tidal pool near the colony of African Penguins Spheniscus demersus. Strain ARHSd-7G was isolated on
mineral anaerobic medium with 3 % NaCl, pH 7 and D-glucose, it has motile, vibrion shape cells, and is Gram
variable. Strain ARHSd-9G grew on anaerobic, alkaline medium with pH 9 and 1 % NaCl at 3°C. The substrate was
D-glucose supplemented with yeast extract (0.05 %). Cells of strain ARHSd-9G had morphology of straight or
slightly curved elongated rods and demonstrated unusual optical effects under dark-field visible light microscopy.
The cells were spore-forming and Gram positive. From the mat sample collected near Lake Zub, the new strain LZ-3
was isolated in pure culture at 3°C. Strain LZ-3 was anaerobic and grew on 0.5 % NaCl mineral medium with Dglucose
as a substrate. The gram positive cells were spore-forming. They exhibited a distinctive morphology of large
rods with rounded ends and size 1x10 μm. From the sample of ice sculpted by wind and melting by solar heating,
containing many entrained black rocks collected near Lake Podprudnoye the new strain ISLP-22 was isolated in
pure culture. The cells of this strain had vibrion shape and were spore-forming and had "baseball bat" shapes). This
culture preferred 0.1 % NaCl mineral anaerobic medium and grew rapidly at 3 °C. Currently, all strains are under
physiological study and phylogenetic analysis.