A novel marine sulfate-reducing bacterium, strain CV2803T, which is able to oxidize aliphatic hydrocarbons, was isolated from a hydrocarbon-polluted marine sediment (Gulf of Fos, France). The cells were rod-shaped and slightly curved, measuring 0.6x2.2-5.5 microm. Strain CV2803T stained Gram-negative and was non-motile and non-spore-forming. Optimum growth occurred in the presence of 24 g NaCl l(-1), at pH 7.5 and at a temperature between 28 and 35 degrees C. Strain CV2803T oxidized alkanes (from C13 to C18) and alkenes (from C7 to C23). The DNA G+C content was 41.4 mol%. Comparative sequence analyses of the 16S rRNA gene and dissimilatory sulfite reductase (dsrAB) gene and those of other sulfate-reducing bacteria, together with its phenotypic properties, indicated that strain CV2803T was a member of a distinct cluster that contained unnamed species. Therefore, strain CV2803T (=DSM 15576T=ATCC BAA-743T) is proposed as the type strain of a novel species in a new genus, Desulfatibacillum aliphaticivorans gen. nov., sp. nov.