Microbial Genome Seqencing: A Genomic Approach to Sulfur Biotransformations in the Ocean: The Genome Sequence of a Marine Roseobacter

University Of Georgia Research Foundation Inc, Athens GA

Investigators

Abstract

The emission of dimethylsulfide (DMS) from the ocean represents the major natural input of sulfur to the Earth's atmosphere. Once in the atmosphere, DMS is rapidly oxidized, forming sulfur aerosols that have an important impact on atmospheric chemistry and the global climate system. Recent evidence points to a key role for members of the marine roseobacter lineage in carrying out these globally-important functions. Representatives of the roseobacter group, including Silicibacter sp. DSS-3, are known to carry out many, if not most, of the major biogeochemical transformations of DMS and its precursor compound, dimethylsulfonioproionate (DMSP). Of particular importance is the fact that organisms like DSS-3 have the ability to produce DMS from DMSP but also the ability to metabolize DMSP by an alternative pathway that bypasses DMS altogether. Little is currently known about how these different pathways are regulated in marine bacteria, or how pathway regulation affects the complex DMS biogeochemistry in the sea. Thus the genome sequence of Silicibacter sp. DSS-3 will provide key information for deciphering how marine bacterioplankton control sulfur emission from the ocean. In this project, a fully closed and annotated sequence of Silicibacter sp. DSS-3 will be obtained, with the goal of developing molecular tools that can be used to investigate the microbiology and ecology of bacterially mediated organic sulfur transformations in the ocean. The roseobacter group is currently the only major lineage of marine heterotrophs whose members can be readily cultured and manipulated in the laboratory. As such, a genome sequence of Silicibacter sp. DSS-3 will also be of broad interest to marine biogeochemists and microbial ecologists. Sequence data will be provided to the scientific community through the TIGR Microbial Database site (www.tigr.org/tdb/tdb.html). Initial release of the sequence data will be in the form of contigs assembled at 3-fold sequence coverage, with monthly data releases thereafter. This is a Microbial Genome Sequencing Award funded through a collaborative activity between the National Science Foundation and the Department of Agriculture Initiative for Future Agriculture and Food Systems.