Halomonas diversa sp. nov., isolated from deep-sea sediment of the Pacific Ocean

Abstract

A novel Gram-stain-negative, facultatively anaerobic, rod-shaped bacterium, designated as D167-6-1T, was isolated from deep-sea sediment collected from the Pacific Ocean. The cells were catalase- and oxidase-positive, and motile by means of peritrichous flagella. Growth occurred at NaCl concentrations ranging from 0 to 19 % (optimum, 2–8 %, w/v), from pH 6 to 11 (optimum, 7–8) and at temperatures between 4 and 45 °C (optimum, 33 °C). Phylogenetic analysis based on 16S rRNA, gyrB and rpoD gene sequences and its genome sequence revealed that strain D167-6-1T formed a monophyletic branch within the genus Halomonas and was most closely related to Halomonas saliphila , Halomonas pellis , Halomonas kenyensis , Halomonas daqingensis , Halomonas desiderata and Halomonas lactosivorans (with 98.5, 98.5, 98.4, 98.1, 97.5 and 97.8 % 16S rRNA sequence similarity, respectively). The complete genome size of strain D167-6-1T was 4.49 Mb, with a DNA G+C content of 62.8 mol%. The estimated averagenucleotide identity and DNA–DNA hybridization values between strain D167-6-1T and other closely related species were 77.59–85.35 % and 22.0–30.6 %, respectively. The principal cellular fatty acids (>5 %) were C18 : 1  ω7c, C16 : 0, C19 : 0 cyclo ω8c, summed feature 3 (C16 : 1  ω7c/C16 : 1  ω6c) and C17 : 0 cyclo. The polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, an unidentified aminolipid, aminophospholipid and two unidentified phospholipids. The predominant respiratory quinones were Q-9 and Q-8. The combined genotypic and phenotypic data show that strain D167-6-1T represents a novel species of the genus Halomonas , for which the name Halomonas diversa sp. nov. is proposed, with the type strain D167-6-1T (=MCCC 1A13316T=KCTC 72441T).