%0 Journal Article
%T Microbial Diversity and Biochemical Potential Encoded by Thermal Spring Metagenomes Derived from the Kamchatka Peninsula
%A Bernd Wemheuer
%A Robert Taube
%A Pinar Akyol
%A Franziska Wemheuer
%A Rolf Daniel
%J Archaea
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/136714
%X Volcanic regions contain a variety of environments suitable for extremophiles. This study was focused on assessing and exploiting the prokaryotic diversity of two microbial communities derived from different Kamchatkian thermal springs by metagenomic approaches. Samples were taken from a thermoacidophilic spring near the Mutnovsky Volcano and from a thermophilic spring in the Uzon Caldera. Environmental DNA for metagenomic analysis was isolated from collected sediment samples by direct cell lysis. The prokaryotic community composition was examined by analysis of archaeal and bacterial 16S rRNA genes. A total number of 1235 16S rRNA gene sequences were obtained and used for taxonomic classification. Most abundant in the samples were members of Thaumarchaeota, Thermotogae, and Proteobacteria. The Mutnovsky hot spring was dominated by the Terrestrial Hot Spring Group, Kosmotoga, and Acidithiobacillus. The Uzon Caldera was dominated by uncultured members of the Miscellaneous Crenarchaeotic Group and Enterobacteriaceae. The remaining 16S rRNA gene sequences belonged to the Aquificae, Dictyoglomi, Euryarchaeota, Korarchaeota, Thermodesulfobacteria, Firmicutes, and some potential new phyla. In addition, the recovered DNA was used for generation of metagenomic libraries, which were subsequently mined for genes encoding lipolytic and proteolytic enzymes. Three novel genes conferring lipolytic and one gene conferring proteolytic activity were identified. 1. Introduction Sites of volcanic activity can be found all over the world and even under the sea. Volcanic regions provide a variety of different environments for extremophilic archaeal and bacterial microorganisms. Well-known examples of such extreme environments are terrestrial surface hot springs. With respect to geographical, physical, environmental, and chemical characteristics, hot springs are unique sites for extremophilic microorganisms [1¨C3]. Extremophiles inhabiting hot springs are considered to be the closest living descendants of the earliest life forms on Earth [4, 5]. Therefore, these springs provide insights into the origin and evolution of life. In addition, thermophiles and hyperthermophiles produce a variety of hydrolytic enzymes such as lipases, glycosidases, peptidases and other biomolecules, which are of industrial interest [6¨C8]. For example, Hotta et al. [9] found an extremely stable carboxylesterase in the hyperthermophilic archaeon Pyrobaculum calidifontis VA1, and Arpigny et al. [10] identified a novel heat-stable lipolytic enzyme in Sulfolobus acidocaldarius DSM 639. Especially in
%U http://www.hindawi.com/journals/archaea/2013/136714/