Description of ‘Desulfobacterium corrodens’ strain IS4 as Desulfosediminibacter corrodens gen. nov. sp. nov. and reclassification of Desulfopila inferna as Desulfosediminibacter infernus comb. nov.

Sulphate-reducing bacteria of the families Desulfobulbaceae and Desulfocapsaceae are ubiquitously distributed and abundant in marine sediments. The present study characterizes strain IS4 ^T , a sulphate reducer that was formerly isolated from a coastal sediment. Phylogenetic analyses based on 16S rRNA gene and marker protein sequences identified Desulfopila inferna JS_SRB250Lac ^T as the closest relative of strain IS4 ^T , which is, however, polyphyletic with the type species Desulfopila aestuarii MSL86 ^T . Both phylogenetic analyses and whole-genome comparisons suggest that strains IS4 ^T and JS_SRB250Lac ^T represent different species of a new genus within the family Desulfocapsaceae . Strains IS4 ^T and JS_SRB250Lac ^T further differ from D. aestuarii MSL86 ^T by their capacity to grow autotrophically, the presence of cyclic fatty acids (C _17 : 0 cyclo ω 7c) and their polar lipids that can include phosphatidylcholine, lysophosphatidylcholine, phosphatidylglycerol and phosphatidylethanolamine, while phosphatidylserine was absent. During lithoautotrophic growth of strain IS4 ^T with metallic iron as an electron donor, molecular hydrogen accumulated to a higher level than it was produced abiotically, suggesting that corrosion potential is a distinguishing feature between strains IS4 ^T and JS_SRB250Lac ^T . On the basis of phenotypic, phylogenetic and genomic characteristics, we propose the novel species and genus Desulfosediminibacter corrodens gen. nov. sp. nov. The type strain is IS4 ^T (=DSM 15630 ^T =JCM 39320 ^T ). In addition, we suggest the reclassification of D. inferna as Desulfosediminibacter infernus comb. nov.