Abstract
Green sulfur bacteria (GSB) (Chlorobiaceae) are primary producers that are important in global carbon and sulfur cycling in natural environments. An almost complete genome sequence for a single, dominant GSB species (C-Ace) was assembled from shotgun sequence data of an environmental sample taken from the O2-H2S interface of the water column of Ace Lake, Antarctica. Approximately 34 Mb of DNA sequence data were assembled into nine scaffolds totaling 1.79 Mb, representing approximately 19-fold coverage for the C-Ace composite genome. A high level (∼ 31%) of metaproteomic coverage was achieved using matched biomass. The metaproteogenomic approach provided unique insight into the protein complement required for dominating the microbial community under cold, nutrient-limited, oxygen-limited and extremely varied annual light conditions. C-Ace shows physiological traits that promote its ability to compete very effectively with other GSB and gain dominance (for example, specific bacteriochlorophylls, mechanisms of cold adaptation) as well as a syntrophic relationship with sulfate-reducing bacteria that provides a mechanism for the exchange of sulfur compounds. As a result we are able to propose an explanation of the active biological processes promoted by cold-adapted GSB and the adaptive strategies they use to thrive under the severe physiochemical conditions prevailing in polar environments.
Original language | English |
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Pages (from-to) | 1002-1019 |
Number of pages | 18 |
Journal | ISME Journal |
Volume | 4 |
Issue number | 8 |
DOIs | |
Publication status | Published - Aug 2010 |
Externally published | Yes |
Keywords
- Antarctic meromictic lake
- cold adaptation
- ecological dominance
- green sulfur bacterium
- metagenomics
- metaproteomics