A Gram-negative, rod-shaped, non-motile and strictly aerobic bacterium, designated ZQ420T, was isolated from marine sediment sampled on Zhoushan Island located in the East China Sea. Strain ZQ420T was able to grow at 10-45 °C, 0-12.0 % (w/v) NaCl and pH 5.5-9.0. Catalase and oxidase activities, nitrate reduction, H2S production, hydrolysis of starch, casein, Tween 20, 40 and 80 were positive. Indole, methyl red, Voges-Proskauer test, hydrolysis of gelatin and Tween 60 were negative. The major cellular fatty acids were C18 : 1 ω7c, C16 : 0 and 11-methyl C18 : 1ω7c. Ubiquinone-10 (Q-10) was the only detected respiratory quinone. The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, three unidentified phospholipids, three unidentified glycolipids, two unidentified aminolipid and two unidentified lipids. The DNA G+C content was 64.8 mol%. According to 16S rRNA gene sequence similarities, strain ZQ420T shared 97.9, 96.3 and 96.3 % similarities to the following species with validated names Pararhodobacteraggregans D1-19T, Pseudo rhodobacter psychrotolerans PAMC27389T and Pseudo rhodobacter collinsensis 4-T-34T, respectively. While sharing lower sequence similarities (<96.0 %) to other type species. Phylogenetic analyses showed that strain ZQ420T and P. aggregans D1-19T formed an independent cluster in the phylogenetic trees. The average nucleotide identity value between strain ZQ420T and P. aggregans D1-19T was 79.1 %. The in silico DNA-DNA hybridization analysis revealed that strain ZQ420T shared 21.5 % DNA relatedness with P. aggregans D1-19T. On the basis of its phenotypic, chemotaxonomic and genotypic characteristics, strain ZQ420T is considered to represent a novel species in the genus Pararhodobacter, for which the name Pararhodobactermarinus sp. nov. is proposed. The type strain is ZQ420T (=KCTC 62579T=MCCC 1K03530T).
Keywords: Pararhodobacter marinus; marine sediment; taxonomy.