Handbook of Hydrocarbon and Lipid Microbiology

Abstract

Members of the Roseobacter lineage of bacteria are prevalent in diverse marine environments where they carry out critical biogeochemical processes. Recent reports, based primarily on culture-independent studies and reviewed here, provide compelling evidence that members of this abundant lineage are involved in hydrocarbon degradation in natural systems. To determine whether cultured representatives possess similar catabolic capabilities, 24 representative Roseobacter genome sequences were searched for genes sharing homology with those known to be involved in the degradation of hydrocarbons and related compounds. Five distinct pathways for the aerobic degradation of aromatic compounds were identified in the genome collection, as were genes encoding alkane hydroxylases and uncharacterized ring-cleaving and -hydroxylating dioxygenases. Taken together, these findings suggest Roseobacters, a group historically overlooked with regard to this physiology, may play important roles in thedegradation of hydrocarbons at both naturally occurring and elevated levels in marine environments.