Diaphorobacter ruginosibacter sp. nov., isolated from soybean root nodule, and emended description of the genus Diaphorobacter.

Abstract

A gram-negative bacterium designated BN30(T), which is motile with a polar flagellum, non-endospores forming, oxidase- and catalase-positive, was isolated from soybean root nodule. The organism is facultative anaerobic and surface-wrinkled rod. It can grow at 10-40°C, pH 6-8 and 6% (w/v) NaCl. BLASTn search based on 16S rRNA gene sequence revealed that the strain is closely related to Diaphorobacter aerolatus 8604S-37(T), Alicycliphilus denitrificans K601(T), Simplicispira limi EMB325(T), Diaphorobacter nitroreducens NA10B(T) and Diaphorobacter oryzae RF3(T), which all belonged to the family Comamonadaceae in class Betaproteobacteria. Phylogenetic analysis showed that the strain formed a firm clade with three Diaphorobacter species, being closest to Diaphorobacter aerolatus 8604S-37(T) with similarity of 98.64%. DNA-DNA relatedness values between strain BN30(T) and five reference strains ranged from 11.5 to 35.9%. All the results of phylogenetic analysis, chemotaxonomical data (predominant fatty acids are C16:0, sum feature 3, sum feature 8 and C17:0 cyclo; major polar lipids are diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol; major quinone is Q-8; G+C of total DNA is 65.2%), physiological and phenotypic results supported that BN30(T) represented a novel species within the genus Diaphorobacter. The name Diaphorobacter ruginosibacter was proposed, and the type strain is BN30(T) (=ACCC06116(T)=DSM 27467(T)).