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 WL0062^T and WL0115, were isolated from coastal zone of the Yellow Sea, Jiangsu Province, PR China, respectively. Strain WL0062^T 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 WL0062^T and WL0115 clustered together with Sedimentimonas flavescens B57^T. 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 WL0062^T were summed features 8 (C_18 : 1  ω6c and/or C_18 : 1  ω7c). The major fatty acids of strain WL0115 were summed features 8 (C_18 : 1  ω6c and/or C_18 : 1  ω7c), C_18 : 0, iso-C_17 : 1  ω5c and C_20 : 4  ω6/9/12/15c (arachidonic acid). The G+C content of genomic DNA of strains WL0062^T 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 WL0062^T represents a novel species of the genus Rhodobacter, for which the name Rhodobacter flavimaris sp. nov is proposed. The type strain is WL0062^T (=MCCC 1K06014^T=JCM 34676^T=GDMCC 1.2427^T). Strain WL0115 (=MCCC 1K07531=JCM 35568=GDMCC 1.3088) should belong to the same species as Sedimentimonas flavescens B57^T. In addition, on the basis of phylogenomic relationship and phenotypical characteristics, the genera Paenirhodobacter, Sedimentimonas, and Sinirhodobacter are proposed as synonyms of Rhodobacter.