Description of Rhodobacter flavimaris sp. nov. and proposal of the genera Paenirhodobacter, Sedimentimonas, and Sinirhodobacter as synonyms of Rhodobacter

Abstract

Two Gram-stain-negative, aerobic, ovoid to short rod-shaped bacterial strains, designated as WL0062T and WL0115, were isolated from coastal zone of the Yellow Sea, Jiangsu Province, PR China, respectively. Strain WL0062T grew optimally at 28 °C, pH 7.0–8.0 and with 1.0–3.0% (w/v) NaCl. Strain WL0115 grew optimally at 28 °C, pH 6.0–7.0 and with 1.0–3.0% (w/v) NaCl. In the bac120 tree, strains WL0062T and WL0115 clustered together with Sedimentimonas flavescens B57T. The respiratory quinone of both strains was ubiquinone-10. The major polar lipids of both strains were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, glycolipid, phosphatidylmonomethylethanolamine, and one unidentified polar lipid. The major fatty acids of strain WL0062T were summed features 8 (C18 : 1 ω6c and/or C18 : 1 ω7c). The major fatty acids of strain WL0115 were summed features 8 (C18 : 1 ω6c and/or C18 : 1 ω7c), C18 : 0, iso-C17 : 1 ω5c and C20 : 4 ω6/9/12/15c (arachidonic acid). The G+C content of genomic DNA of strains WL0062T and WL0115 was 64.0 mol% in both of them. Combined with the analysis of average nucleotide identity, average amino acid identity, and digital DNA–DNA hybridization, strain WL0062T represents a novel species of the genus Rhodobacter, for which the name Rhodobacter flavimaris sp. nov is proposed. The type strain is WL0062T (=MCCC 1K06014T=JCM 34676T=GDMCC 1.2427T). Strain WL0115 (=MCCC 1K07531=JCM 35568=GDMCC 1.3088) should belong to the same species as Sedimentimonas flavescens B57T. In addition, on the basis of phylogenomic relationship and phenotypical characteristics, the genera Paenirhodobacter, Sedimentimonas, and Sinirhodobacter are proposed as synonyms of Rhodobacter.