Paradesulfovibrio onnuriensis gen. nov., sp. nov., a chemolithoautotrophic sulfate-reducing bacterium isolated from the Onnuri vent field of the Indian Ocean and reclassification of Desulfovibrio senegalensis as Paradesulfovibrio senegalensis comb. nov.

Abstract

An anaerobic, rod-shpaed, mesophilic, chemolithoautotrophic, sulfate-reducing bacterium, strain IOR2T was isolated from a newly found deep-sea hydrothermal vent (OVF, Onnuri Vent Field) area in central Indian Ocean ridge (11o24’88” S 66o25’42” E, 2021 m water depth). The 16S rRNA gene sequence analysis revealed that strain IOR2T was most closely related to Desulfovibrio senegalensis BLaC1T (96.7%). However, it showed low similarity with members of the family Desulfovibrionaceae, such as Desulfovibrio tunisiensis RB22T (94.0), D. brasiliensis LVform1T (93.9%), D. halophilius DSM5663T (93.7), and Pseudodesulfovibrio aespoeensis Aspo-2T (93.2%). Strain IOR2T could grow at 23-42 oC (optimum, 37oC), pH 5.0-8.0 (pH 7.0) and with 0.5-6.5% (3.0%) NaCl. The strain could use lactate, pyruvate, H2 and glycerol as electron donors, and sulfate, thiosulfate and sulfite as electron acceptors. The strain could grow with CO2 + H2 as sole carbon and energy source. The major fatty acids of strain IOR2T were iso-C15:0, iso-C17:0, anteiso-C15:0, and summed feature 9 (C16:0 methyl/iso-C17:1ω9c). The DNA G+C content of strain IOR2T was 60.1 mol%. Based on the results of phylogenetic and physiologicstudies, Paradesulfovibrio onnuriensis gen. nov., sp. nov., with the type strain IOR2T (=KCTC 15845T) is proposed in the family Desulfovibrionaceae. We also propose the reclassification of D. senegalensis as Paradesulfovibrio senenglaensis