Marinobacterium mangrovicola sp. nov., a marine nitrogen-fixing bacterium isolated from mangrove roots of Rhizophora mangle

Abstract

A nitrogen-fixing marine bacterium, designated strain Gal22T, was isolated from mangrove roots of Rhizophora mangle. Cells were Gram-stain-negative rods, motile with a single polar flagellum. Growth was observed at 4–42 °C, pH 5.5 to 10 and with 0–18 % (w/v) NaCl. Strain Gal22T was positive for catalase and oxidase. Q-8 was the predominant lipoquinone. The DNA G+C content was 57.0 mol%. Based on phylogenetic analysis of 16S rRNA gene, strain Gal22T belongs to the genus Marinobacterium . The closely related strains were shown to be Marinobacterium lutimaris DSM 22012T and Marinobacterium litorale IMCC1877T with 99 % and 96 % 16S rRNA gene sequence similarity, respectively. DNA–DNA relatedness analysis indicated that strain Gal22T was different from M. lutimaris DSM 22012T. On the basis of genotypic, morphological and biochemical characteristics, a novel species, Marinobacterium mangrovicola sp. nov. (type strain, Gal22T = DSM 27697T = CIP 110653T), is proposed.