Paenibacillus taohuashanense sp. nov., a nitrogen-fixing species isolated from rhizosphere soil of the root of Caragana kansuensis Pojark

Abstract

A nitrogen-fixing bacterium, designated strain gs65(T), was isolated from a rhizosphere soil sample of Caragana kansuensis Pojark. Phylogenetic analysis based on a fragment of the nifH gene and the full-length 16S rRNA gene sequence revealed that strain gs65(T) is a member of the genus Paenibacillus. High levels of 16S rRNA gene similarity were found between strain gs65(T) and Paenibacillus borealis DSM 13188(T) (97.5 %), Paenibacillus odorifer ATCC BAA-93(T) (97.3 %), Paenibacillus durus DSM 1735(T) (97.0 %) and Paenibacillus sophorae DSM23020(T) (96.9 %). Levels of 16S rRNA gene sequence similarity between strain gs65(T) and the type strains of other recognized members of the genus Paenibacillus were below 97.0 %. Levels of DNA-DNA relatedness between strain gs65(T) and P. borealis DSM 13188(T), P. odorifer ATCC BAA-93(T) (97.3 %), P. durus DSM 1735(T) and P. sophorae DSM23020(T) were 35.9, 38.0, 34.2 and 35.5 % respectively. The DNA G+C content of strain gs65(T) was determined to be 51.6 mol%. The major fatty acids were found to be iso-C(14:0), anteiso-C(15:0) and iso-C(16:0). On the basis of its phenotypic characteristics and levels of DNA-DNA hybridization, strain gs65(T) is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus taohuashanense sp. nov. is proposed. The type strain is gs65(T) (=CGMCC 1.12175(T) = DSM 25809(T)).