Bradymonas sediminis gen. nov., sp. nov., isolated from coastal sediment, and description of Bradymonadaceae fam. nov. and Bradymonadales ord. nov.

Abstract

A novel Gram-stain-negative, rod-shaped, gliding, facultatively anaerobic, oxidase-negative and catalase-positive bacterium, designated FA350T, was isolated from coastal sediment from Xiaoshi Island, Weihai, China. Strain FA350T showed growth on modified nutrient agar supplemented with 0.1 % d-(+)-trehalose and with distilled water replaced by seawater. Optimal growth occurred at 33 °C and pH 8.5 with 4 % NaCl. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain FA350T belongs to a novel bacterial order in the class Deltaproteobacteria , and the most closely related type strains belong to the order Desulfuromonadales , with 85.1–85.6 % 16S rRNA gene sequence similarity. The polar lipid profile of the novel strain consisted of phosphatidylethanolamine, phosphatidylglycerol and two unknown phospholipids. Major cellular fatty acids were iso-C15 : 0, iso-C17 : 0 and iso-C17 : 1ω10c and menaquinone MK-7 was the sole respiratory quinone. The DNA G+C content of strain FA350T was 60.3 mol%. The isolate and closely related environmental clones formed a novel order-level clade in the class Deltaproteobacteria . Comparative analysis of 16S rRNA gene sequences and characterization indicated that strain FA350T may represent a novel order of the Deltaproteobacteria . Here, we propose the name Bradymonas sediminis gen. nov., sp. nov. to accommodate strain FA350T. The type strain of Bradymonas sediminis is FA350T ( = DSM 28820T = CICC 10904T); Bradymonadales ord. nov. and Bradymonadaceae fam. nov. are also proposed to accommodate the novel taxon.