DESULFOSPIRA JOERGENSENII, GEN-NOV, SP-NOV, A NEW SULFATE-REDUCING BACTERIUM ISOLATED FROM MARINE SURFACE SEDIMENT

A new Gram-negative sulfur-reducing eubacterium was isolated from iron -rich oxidized marine surface sediment with elemental sulfur and butyr ate. Elemental sulfur can be substituted by sulfate. In addition, thio sulfate and sulfite are used as electron acceptors. The strain, named B331, grows well in hydrogen sulfide free medium in the presence of hi gh concentrations of amorphous iron (FeIII) hydroxide. The substrate s pectrum is versatile and includes hydrogen, fatty acids, dicarboxylic acids, oxoacids, hydroxyacids, compatible solutes (choline, chloride, betaine, glycerol and proline) and yeast extract. A fermentative type of metabolism was not observed. The cells are vibrio-shaped and not mo tile. The G + C content of the genomic DNA is 49.3 mol%. Cytochromes a re present, desulfoviridin is not. The major lipoquinones present are menaquinones including both MK-7 and MK-7(VII-H,). The fatty acid comp osition comprises mainly unbranched fatty acids. The major polar lipid s are phosphatidyl glycerol and phosphatidyl ethanolamine. Comparative 16S rDNA sequence analysis placed strain B331 into the delta subgroup of proteobacteria originating in a common root with members of the ge nera Desulfobacter and Desulfobacula. Within this group it forms a dis tinct line of descent with Desulfobacula toluolica as the most closely related microorganism. Strain B331, is described as the type species and type strain, respectively, of a new taxon, Desulfospira joergensen ii gen. nov., sp. nov.