Isolation, Characterization, and Ecology of Cold-Active, Chemolithotrophic, Sulfur-Oxidizing Bacteria from
Novel strains of obligately chemolithoautotrophic, sulfur-oxidizing bacteria have been isolated from various depths of Lake Fryxell, Antarctica. Physiological, morphological, and phylogenetic analyses showed these strains to be related to mesophilic Thiobacillus species, such as T. thioparus. Howeve...
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Format: | Text |
Language: | English |
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2006
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Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.486.2507 http://www.mbio.ncsu.edu/MJC/old/20062007/Rebecca_Paper.pdf |
Summary: | Novel strains of obligately chemolithoautotrophic, sulfur-oxidizing bacteria have been isolated from various depths of Lake Fryxell, Antarctica. Physiological, morphological, and phylogenetic analyses showed these strains to be related to mesophilic Thiobacillus species, such as T. thioparus. However, the psychrotolerant Antarctic isolates showed an adaptation to cold temperatures and thus should be active in the nearly freezing waters of the lake. Enumeration by most-probable-number analysis in an oxic, thiosulfate-containing medium revealed that the sulfur-oxidizing chemolithotroph population peaks precisely at the oxycline (9.5 m), although viable cells exist well into the anoxic, sulfidic waters of the lake. The sulfur-oxidizing bacteria described here likely play a key role in the biogeochemical cycling of carbon and sulfur in Lake Fryxell. The role of sulfur-oxidizing bacteria (SOB) in carbon and sulfur cycling has been well studied in both temperate and geothermal aquatic environments (1, 17, 29). Many metaboli-cally and phylogenetically diverse organisms involved in sulfur cycling have been isolated in pure culture from these environ-ments and characterized in detail (6, 10, 32, 36). However, the same cannot be said for sulfur-oxidizing chemolithotrophs in |
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