Desulfovibrio magneticus sp nov., a novel sulfate-reducing bacterium that produces intracellular single-domain-sized magnetite particles

A novel type of dissimilatory sulfate-reducing bacterium, designated strain RS-1(T), capable of producing intracellular magnetite particles (magnetosomes) was isolated from freshwater sulfide-rich sediments. Phylogenetic analysis based on 16S rDNA sequences revealed that RS-1(T) is a member of the genus Desulfovibrio. Its closest known relative is Desulfovibrio burkinensis (sequence similarity of 98.7%). Strain RS-1(T) contains desulfoviridin, c-type cytochromes and, unlike other Desulfovibrio spp., it possesses menaquinone MK-7(H-2) instead of MK-6 or MK-6(H-2). Strain RS-1(T) is also unique compared with other members of Desulfovibrio in its ability to synthesize intracellular magnetite particles. A novel species, Desulfovibrio magneticus sp. nov., is proposed for RS-1(T) (= ATCC 700980(T) = DSM 13731(T)), a sulfate-reducing magnetotactic bacterium.