Sulfidogenesis encompasses microbial reduction of sulfate and other sulfur compounds. It is the main mineralization process in organic-rich surface sediments in the deep anoxic basin of the Black Sea. Here, sulfate reduction is thought to be mediated by deltaproteobacterial sulfate-reducing bacteria (SRB) and other, currently unidentified sulfidogens. We present a cultivation-based study to investigate the diversity and identity of sulfidogens in sediment samples from the Black Sea at 2,100 m depth. We set up enrichments with combinations of the electron donors H2, formate, acetate, propionate, butyrate, or lactate, and the electron acceptors sulfate, thiosulfate or S0, and analyzed the enriched communities with 16S rRNA gene amplicon sequencing. This resulted in enriched putative sulfidogens (Desulfobacteraceae, Desulfobulbaceae) as well as fermentative bacteria. In sulfate-reducing, acetate-degrading enrichments, Aegiribacteria/Fermentibacteria ssp. were enriched. In sulfur-reducing, acetate-degrading dilution enrichments, Desulfuromonadales Sva1033 bacteria became abundant. Sulfur-disproportionating enrichments contained canonical Desulfocapsa spp., but also other putatively disproportionating Desulfobulbaceae members. We isolated and characterized a novel SRB of the Desulfopila genus, strain LS5BT, with lactate as original substrate. Strain LS5BT was an incomplete oxidizer producing acetate from lactate during sulfate reduction, despite encoding the presumably bidirectional acetyl-CoA pathway, similar to its facultatively lithoautotrophic close relative Desulfopila inferna JS_SRB250LacT. Strain LS5BT had the capacity for dissimilatory manganese reduction, which is an unusual trait among SRB and of which the mechanism is unknown. We propose strain LS5BT represents the novel species Desulfopila canfieldii.