Comparative physiology of organohalide-respiring bacteria

Abstract

The potential for reductive organohalide respiration is relatively widespread among bacteria. In this chapter, we highlight metabolic differences between facultative and obligate organohalide-respiring bacteria. In addition, we compare the genomic architecture and evolution of the bacteria that comprise the obligate organohalide respiring Dehalococcoides, Dehalobacter, and Dehalogenimonas genera. Major unresolved questions remain about the necessary and sufficient enzymes for energy conservation coupled to reductive dehalogenation in these microorganisms. Although comparative physiology among these three genera reveals considerable metabolic and eco-physiological diversity consistent with their unique phylogeny, these microorganisms share similar genomic signatures, suggestive of convergent adaptive niche specialization to catabolism of naturally occurring organohalide compounds.