Defluviimonas indica sp. nov., a marine bacterium isolated from a deep-sea hydrothermal vent environment

A Gram-stain-negative, strictly aerobic, chemoheterotrophic marine bacterium, designated 20V17(T), was isolated from a deep-sea hydrothermal vent chimney collected from the South-west Indian Ridge. Cells of strain 20V17(T) were motile, short rods, 1.2-1.8 µm in length and 0.5-0.7 µm in width. Growth was observed at between 20 and 37 °C (optimum 25 °C-28 °C), pH 5.0 and 8.0 (optimum pH 7.0) and 0.5 and 8% (w/v) NaCl (optimum 1.5-2.0% NaCl). The major fatty acids were C(18 : 1)ω7c (74.4%), C(19 : 0) cyclo ω8c (11%), C(18 : 0) (5.1%) and C(18 : 0) 3-OH (2.8%), and the polar lipid profile comprised diphosphatidylglycerol, phosphatidylethanolamine, an unidentified glycolipid and four unidentified phospholipids. Ubiquinone 10 was the major quinone. The G+C content of genomic DNA was 66.3 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain 20V17(T) belonged to the genus Defluviimonas and shared 96.5 and 96.1% sequence similarity with Defluviimonas denitrificans D9-3(T) and Defluviimonas aestuarii BS14(T), respectively. On the basis of the taxonomic data obtained in this study, strain 20V17(T) represents a novel species of the genus Defluviimonas, for which the name Defluviimonas indica sp. nov. is proposed. The type strain is 20V17(T) (CGMCC 1.10859(T) = JCM 17871(T) = MCCC 1A01802(T)).