Abstract

A moderately halophilic bacterial strain 15-13T, which was isolated from soda meadow saline soil in Daqing City, Heilongjiang Province, China, was subjected to a polyphasic taxonomic study. The cells of strain 15-13T were found to be Gram-negative, rod-shaped, and motile. The required growth conditions for strain 15-13T were: 1-23% NaCl (optimum, 7%), 10-50°C (optimum, 35°C), and pH 7.0-11.0 (optimum, pH 9.5). The predominant cellular fatty acids were C18:1 ω7c (60.48%) and C16:0 (13.96%). The DNA G+C content was 67.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequence comparisons indicated that strain 15-13T clustered within a branch comprising species of the genus Halomonas. The closest phylogenetic neighbor of strain 15-13T was Halomonas pantelleriensis DSM 9661T (98.9% 16S rRNA gene sequence similarity). The level of DNA-DNA relatedness between the novel isolated strain and H. pantelleriensis DSM 9661T was 33.8%. On the basis of the phenotypic and phylogenetic data, strain 15-13T represents a novel species of the genus Halomonas, for which the name Halomonas alkalitolerans sp. nov. is proposed. The type strain for this novel species is 15-13T (=CGMCC 1.9129T =NBRC 106539T).

• Keywords: Halomonas alkalitolerans sp. nov.; 16S rRNA gene sequence; fatty acid composition; DNA-DNA hybridization