Exploring the Genome and Proteome of Desulfitobacterium hafniense DCB2 for its Protein Complexes Involved in Metal Reduction and Dechlorination

Desulfitobacterium hafniense is an anaerobic, low GC, Gram-positive spore-forming bacterium that shows considerable promise as a bioremediative competent population of sediments. Of particular relevance to its remediation capabilities are metal reduction, which changes the mobility and toxicity of metals, and chlororespiration, the ability to dechlorinate organic xenobiotics. Our work focuses on these two capabilities in D. hafniense DCB2 whose genome was recently sequenced by JGI and annotated by ORNL. We are determining the complete metal reducing repertoire of D. hafniense and the genes required for respiratory and non-respiratory metal reduction through DNA microarrays produced by ORNL and proteomics. In addition, genomic analysis identified seven putative reductive dehalogenases (RDases) and we are investigating these with genetic and biochemical tools. The status of these efforts is presented below.