ena-STUDY-Center of Applied Geosciences-11-05-2015-16:44:30:807-121
Microbial community composition in acidic and pH neutral sediments from two hypersaline lakes in Western Australia
Hypersaline environments, especially salt lakes, are extreme habitats for microbial life. The water bodies and sediments of salt lakes in Western Australia show a wide range of geochemical conditions. However, little is known about the composition and potential functions of the native microbial communities in these ecosystems. Here we compared microbial communities in the sediments of two salt lakes in Western Australia, slightly acidic Lake Orr and slightly alkaline Lake Strawbridge. Community composition was determined by 454 pyrosequencing of bacterial and archaeal 16S rRNA genes. The diversity and richness within the slightly acidic sediments of Lake Orr were lower compared to the pH neutral to alkaline sediments of Lake Strawbridge. Furthermore both salt lakes strongly differed regarding their geochemistry and microbial community composition. The archaeal community in both lakes was dominated by the Halobacteriacea, whereas Proteobacteria, Firmicutes and Bacteroidetes dominated the bacterial community. Inferred from the 16S rRNA gene based microbial community composition we found a high metabolic diversity including heterotrophic organisms, phototrophs, methanogens, fermenters, autotrophic organisms, sulfate reducers, sulfur oxidizers and metal reducers. The high phylogenetic and metabolic diversity in the salt lakes suggests that hypersaline lakes are important ecosystems with an active contribution to various biogeochemical element cycles.
Hypersaline environments, especially salt lakes, are extreme habitats for microbial life. The water bodies and sediments of salt lakes in Western Australia show a wide range of geochemical conditions. However, little is known about the composition and potential functions of the native microbial communities in these ecosystems. Here we compared microbial communities in the sediments of two salt lakes in Western Australia, slightly acidic Lake Orr and slightly alkaline Lake Strawbridge. Community composition was determined by 454 pyrosequencing of bacterial and archaeal 16S rRNA genes. The diversity and richness within the slightly acidic sediments of Lake Orr were lower compared to the pH neutral to alkaline sediments of Lake Strawbridge. Furthermore both salt lakes strongly differed regarding their geochemistry and microbial community composition. The archaeal community in both lakes was dominated by the Halobacteriacea, whereas Proteobacteria, Firmicutes and Bacteroidetes dominated the bacterial community. Inferred from the 16S rRNA gene based microbial community composition we found a high metabolic diversity including heterotrophic organisms, phototrophs, methanogens, fermenters, autotrophic organisms, sulfate reducers, sulfur oxidizers and metal reducers. The high phylogenetic and metabolic diversity in the salt lakes suggests that hypersaline lakes are important ecosystems with an active contribution to various biogeochemical element cycles.