Motiliproteus sediminis gen. nov., sp. nov., isolated from coastal sediment

A novel Gram-stain-negative, rod-to-spiral-shaped, oxidase- and catalase- positive and facultatively aerobic bacterium, designated HS6^T, was isolated from marine sediment of Yellow Sea, China. It can reduce nitrate to nitrite and grow well in marine broth 2216 (MB, Hope Biol-Technology Co., Ltd) with an optimal temperature for growth of 30–33 °C (range 12–45 °C) and in the presence of 2–3 % (w/v) NaCl (range 0.5–7 %, w/v). The pH range for growth was pH 6.2–9.0, with an optimum at 6.5–7.0. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that the novel isolate was 93.3 % similar to the type strain of Neptunomonas antarctica, 93.2 % to Neptunomonas japonicum and 93.1 % to Marinobacterium rhizophilum, the closest cultivated relatives. The polar lipid profile of the novel strain consisted of phosphatidylethanolamine, phosphatidylglycerol and some other unknown lipids. Major cellular fatty acids were summed feature 3 (C_16:1 ω7c/iso-C_15:0 2-OH), C_18:1 ω7c and C_16:0 and the main respiratory quinone was Q-8. The DNA G+C content of strain HS6^T was 61.2 mol %. Based on the phylogenetic, physiological and biochemical characteristics, strain HS6^T represents a novel genus and species and the name Motiliproteus sediminis gen. nov., sp. nov., is proposed. The type strain is HS6^T (=ATCC BAA-2613^T=CICC 10858^T).