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).