Draft Genome Sequence of Sphingomonas sp. Strain Ant20, Isolated from Oil-Contaminated Soil on Ross Island, Antarctica.

Here, we present the draft genome of Sphingomonas sp. strain Ant20, isolated from oil-polluted soil near Scott Base, Ross Island, Antarctica. The genome of this aromatic hydrocarbon-degrading bacterium provides valuable information on the microbially mediated biodegradation of aromatic compounds in cold-climate systems.

Draft Genome Sequence of Microbacterium sp. Strain CH12i, Isolated from Shallow Groundwater in Cape Hallett, Antarctica.

The Antarctic continent is largely covered by an expansive ice sheet, but it harbors diverse terrestrial and aquatic habitats in the coastal ice-free continental margins. Here we present the draft genome of Microbacterium sp. CH12i, which was isolated from hypersaline, alkaline, and nutrient-rich groundwater from Cape Hallett, northern Victoria Land, Antarctica.

Draft Genome Sequence of the Aromatic Hydrocarbon-Degrading Bacterium Sphingobium sp. Strain Ant17, Isolated from Antarctic Soil.

Here, we present the draft genome sequence of Sphingobium sp. strain Ant17, an aromatic hydrocarbon-degrading bacterium that was isolated from Antarctic oil-contaminated soil. An analysis of this genome can lead to insights into the mechanisms of xenobiotic degradation processes at low temperatures and potentially aid in bioremediation applications.

Draft Genome Sequence of Williamsia sp. Strain D3, Isolated From the Darwin Mountains, Antarctica.

Actinobacteria are the dominant taxa in Antarctic desert soils. Here, we describe the first draft genome of a member of the genus Williamsia (strain D3) isolated from Antarctic soil. The genome of this psychrotolerant bacterium may help to elucidate crucial survival mechanisms for organisms inhabiting cold desert soil systems.

Bacterial composition of soils of the Lake Wellman area, Darwin Mountains, Antarctica.

The aim of this study was to examine the bacterial composition of high latitude soils from the Darwin-Hatherton glacier region of Antarctica. Four soil pits on each of four glacial drift sheets were sampled for chemical and microbial analyses. The four drifts-Hatherton, Britannia, Danum, and Isca-ranged, respectively, from early Holocene (10 ky) to mid-Quaternary (ca 900 ky). Numbers of culturable bacteria were low, with highest levels detected in soils from the younger Hatherton drift. DNA was extracted and 16S rRNA gene clone libraries prepared from samples below the desert pavement for each of the four drift sheets. Between 31 and 262 clones were analysed from each of the Hatherton, Britannia, and Danum drifts. Bacterial sequences were dominated by members of the phyla Deinococcus-Thermus, Actinobacteria, and Bacteroidetes. Culturable bacteria, including some that clustered with soil clones (e.g., members of the genera Arthrobacter, Adhaeribacter, and Pontibacter), belonged to Actinobacteria and Bacteroidetes. The isolated bacteria are ideal model organisms for genomic and phenotypic investigations of those attributes that allow bacteria to survive and/or grow in Antarctic soils because they have close relatives that are not tolerant of these conditions.

Hydrocarbon contamination changes the bacterial diversity of soil from around Scott Base, Antarctica.

A combination of culture-independent and culturing methods was used to determine the impacts of hydrocarbon contamination on the diversity of bacterial communities in coastal soil from Ross Island, Antarctica. While numbers of culturable aerobic heterotrophic microbes were 1-2 orders of magnitude higher in the hydrocarbon-contaminated soil than control soil, the populations were less diverse. Members of the divisions Fibrobacter/Acidobacterium, Cytophaga/Flavobacterium/Bacteroides, Deinococcus/Thermus, and Low G+C gram positive occurred almost exclusively in control soils whereas the contaminated soils were dominated by Proteobacteria; specifically, members of the genera Pseudomonas, Sphingomonas and Variovorax, some of which degrade hydrocarbons. Members of the Actinobacteria were found in both soils.

Hydrocarbon spills on Antarctic soils: effects and management.

Antarctic exploration and research have led to some significant although localized impacts on the environment. Human impacts occur around current or past scientific research stations, typically located on ice-free areas that are predominantly soils. Fuel spills, the most common occurrence, have the potential to cause the greatest environmental impact in the Antarctic through accumulation of aliphatic and aromatic compounds. Effective management of hydrocarbon spills is dependent on understanding how they impact soil properties such as moisture, hydrophobicity, soil temperature, and microbial activity. Numbers of hydrocarbon-degrading bacteria, typically Rhodococcus, Sphingomonas, and Pseudomonas species for example, may become elevated in contaminated soils, but overall microbial diversity declines. Alternative management practices to the current approach of "dig it up and ship it out" are required but must be based on sound information. This review summarizes current understanding of the extent and effects of hydrocarbon spillage on Antarctic soils; the observed physical, chemical, and biological responses of such soils; and current gaps in knowledge.