Paenibacillus sophorae sp. nov., a nitrogen-fixing species isolated from the rhizosphere of Sophora japonica.

A nitrogen-fixing bacterium, designated strain S27(T), was isolated from rhizosphere soil of Sophora japonica. Phylogenetic analysis based on a fragment of the nifH gene and the full-length 16S rRNA gene sequence revealed that strain S27(T) is a member of the genus Paenibacillus. High levels of 16S rRNA gene sequence similarity were found between strain S27(T) and Paenibacillus durus DSM 1735(T) (97.3 %), Paenibacillus sabinae DSM 17841(T) (96.9 %), Paenibacillus forsythiae DSM 17842(T) (96.7 %) and Paenibacillus zanthoxyli DSM 18202(T) (96.6 %). However, DNA-DNA hybridization values between strain S27(T) and the four type strains were 37.64 %, 23.12 %, 25.6 % and 34.99 %, respectively. Levels of 16S rRNA gene sequence similarity between strain S27(T) and the type strains of other recognized members of the genus Paenibacillus were below 96.5 %. The DNA G+C content of strain S27(T) was 46.0 mol%. The major fatty acids were anteiso-C(15 : 0), C(16 : 0) and iso-C(16 : 0). The major isoprenoid quinone was MK-7. On the basis of its phenotypic characteristics and DNA-DNA hybridization results, strain S27(T) is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus sophorae sp. nov. is proposed. The type strain is S27(T) ( = CGMCC 1.10238(T)  = DSM 23020(T)).