Dataset Information

Brine assemblages of ultrasmall microbial cells within the ice cover of Lake Vida, Antarctica.

ABSTRACT: The anoxic and freezing brine that permeates Lake Vida's perennial ice below 16 m contains an abundance of very small (?0.2-?m) particles mixed with a less abundant population of microbial cells ranging from >0.2 to 1.5 ?m in length. Fluorescent DNA staining, electron microscopy (EM) observations, elemental analysis, and extraction of high-molecular-weight genomic DNA indicated that a significant portion of these ultrasmall particles are cells. A continuous electron-dense layer surrounding a less electron-dense region was observed by EM, indicating the presence of a biological membrane surrounding a cytoplasm. The ultrasmall cells are 0.192 ± 0.065 ?m, with morphology characteristic of coccoid and diplococcic bacterial cells, often surrounded by iron-rich capsular structures. EM observations also detected the presence of smaller unidentified nanoparticles of 0.020 to 0.140 ?m among the brine cells. A 16S rRNA gene clone library from the brine 0.1- to 0.2-?m-size fraction revealed a relatively low-diversity assemblage of Bacteria sequences distinct from the previously reported >0.2-?m-cell-size Lake Vida brine assemblage. The brine 0.1- to 0.2-?m-size fraction was dominated by the Proteobacteria-affiliated genera Herbaspirillum, Pseudoalteromonas, and Marinobacter. Cultivation efforts of the 0.1- to 0.2-?m-size fraction led to the isolation of Actinobacteria-affiliated genera Microbacterium and Kocuria. Based on phylogenetic relatedness and microscopic observations, we hypothesize that the ultrasmall cells in Lake Vida brine are ultramicrocells that are likely in a reduced size state as a result of environmental stress or life cycle-related conditions.

SUBMITTER: Kuhn E

PROVIDER: S-EPMC4054151 | biostudies-literature | 2014 Jun

REPOSITORIES: biostudies-literature

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Brine assemblages of ultrasmall microbial cells within the ice cover of Lake Vida, Antarctica.

Kuhn Emanuele E Ichimura Andrew S AS Peng Vivian V Fritsen Christian H CH Trubl Gareth G Doran Peter T PT Murray Alison E AE

Applied and environmental microbiology 20140601 12

The anoxic and freezing brine that permeates Lake Vida's perennial ice below 16 m contains an abundance of very small (≤0.2-μm) particles mixed with a less abundant population of microbial cells ranging from >0.2 to 1.5 μm in length. Fluorescent DNA staining, electron microscopy (EM) observations, elemental analysis, and extraction of high-molecular-weight genomic DNA indicated that a significant portion of these ultrasmall particles are cells. A continuous electron-dense layer surrounding a les ...[more]

PMID: 24727273

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Dataset Information

Brine assemblages of ultrasmall microbial cells within the ice cover of Lake Vida, Antarctica.

Publications

Brine assemblages of ultrasmall microbial cells within the ice cover of Lake Vida, Antarctica.

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