Roseivivax sediminis sp. nov., a moderately halophilic bacterium isolated from salt mine sediment.

ABSTRACT

A Gram-negative, facultatively anaerobic, short rod-shaped, heterotrophic bacterium, designated strain YIM D21(T), was isolated from a salt mine in Yunnan province, south-west China. Strain YIM D21(T) formed cream-yellow colonies, was non-motile and moderately halophilic, and tolerated NaCl concentrations of 1-15% (w/v), with optimum growth at 5-10 % (w/v). Growth occurred at 15-42 °C (optimum 28 °C) and at pH 6.5-8.5 (optimum 7.5-8.0). The respiratory quinone was ubiquinone-10 (Q-10). The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, three unidentified phospholipids, one unidentified aminolipid and two unidentified lipids. The major fatty acids were C(181)ω7c and cyclo C(190)ω8c and the DNA G+C content was 67.7 mol%. Phylogenetic analyses revealed that strain YIM D21(T) belongs to the genus Roseivivax. 16S rRNA gene sequence similarities of YIM D21(T) were 95.7, 95.0 and 94.8% with the type strains of Roseivivax halodurans, Roseivivax lentus and Roseivivax halotolerans, respectively. Physiological and biochemical tests allowed phenotypic differentiation of strain YIM D21(T) from closely related species with validly published names. We therefore propose that this isolate represents a novel species, Roseivivax sediminis sp. nov.; the type strain is YIM D21(T) ( = KCTC 23444(T) = ACCC 10710(T)).