Bacillus radicibacter sp. nov., a new bacterium isolated from root nodule of Oxytropis ochrocephala Bunge.

A Gram-positive, facultative anaerobic, rod-shaped, and endospore-forming strain, designated 53-2(T) was isolated from the root nodule of Oxytropis ochrocephala Bunge growing on Qilian mountain, China. The strain can grow at pH 7.0-8.0, 10-50 °C and tolerate up to 11% NaCl. Optimal growth occurred at pH 7.2 and 37 °C. The result of BLASTn search based on 16S rRNA gene sequence revealed that strain 53-2(T) , being closest related to Bacillus acidicola 105-2(T) , possessed remote similarity (less than 95.64%) to the species within genus Bacillus. The DNA G + C content was 37.8%. Chemotaxonomic data (major quinone is MK-7; major polar lipids are diphosphatidylglycerol, phosphatidylglycerol, unknown phospholipid, and aminoglycophospholipid; fatty acids are anteiso-C15: 0 , iso-C15:0 and anteiso-C17: 0 ) supported the affiliation of the isolate to the genus Bacillus. On the basis of physiological, phylogenetic, and biochemical properties, strain 53-2(T) represents a novel species within genus Bacillus, for which the name Bacillus radicibacter is proposed. The type strain is 53-2(T) (=DSM27302(T) =ACCC06115(T) =CCNWQLS5(T) ).

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

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)).