Ensifer sojae sp nov., isolated from root nodules of Glycine max grown in saline-alkaline soils

Thirteen bacterial isolates from root nodules of soybean grown in saline-alkaline soils in the Chinese province of Hebei were identified as a unique group in the genus Ensifer based upon BOX-PCR patterns, sequencing analyses of 16S rRNA and housekeeping genes and DNA-DNA hybridization. Phenotypically, positive tests for acid production and negative results for reduction in litmus milk and sensitivity to 50 mu g ampicillin ml(-1), as well as some other features, could differentiate the novel group from defined species of the Ensifer-Sinorhizobium group. The novel group had symbiotic gene sequences (nodC and nifH) that were identical or very similar to those of Ensifer (Sinorhizobium) fredii, and formed effective nodules with Glycine max (soybean), Vigna unguiculata and Glycine soja. Based upon the consensus of these analyses, a novel species, Ensifer sojae sp. nov., is proposed, with CCBAU 05684(T) (= LMG 25493(T) = HAMBI 3098(T)) as the type strain. The DNA G+C content of strain CCBAU 05684T was 60.9 mol% (T-m).