Complete Genome Sequence and Updated Annotation of

reducing bacterium (SRB), known to corrode ferrous metals and to reduce toxic radionuclides and metals such as uranium and chromium to sparingly soluble and less toxic forms. We present the 3.7-Mb genome sequence to provide insights into its physiology. Desulfovibrio desulfuricans G100A is a deltaproteobacterium that was isolated from a producing oil well in Ventura County, California (8). Strain G20 is a spontaneously nalidixic acid-resistant derivative of G100A that is also lacking the endoge-nous cryptic 2.3-kb plasmid, pBG1 (6). Strictly anaerobic sulfate-reducing bacteria (SRB) of the Desulfovibrio genus have provided a rich experimental system for understanding energy conversion because of their ability to respire sulfate, ferment organic acids, and live in syntrophic associations. Hydrogen metabolism appears to be fundamental for these growth modes. In 1981, Odom and Peck (4) proposed the hydrogen-cycling model as an explanation for the hydroge