Bacillus endoradicis sp. nov., an endophytic bacterium isolated from soybean root.

A Gram-positive, aerobic, motile rod, designated strain CCBAU 05776T, was isolated from the inner tissues of a healthy soybean (Glycine max L.) root collected from an agricultural field in the countryside of Shijiazhuang city, Hebei Province, China. Phylogenetic analysis of the 16S rRNA gene indicated that this strain was most closely related to Bacillus muralis LMG 20238T and Bacillus simplex NBRC 15720T with similarity of 96.5 % and 96.3 %, respectively, lower than the suggested threshold (97.0 %) for separating bacterial species. In phenotypic characterization, the novel strain differed from the two most related species in that it did not hydrolyse casein or starch but could grow on MacConkey agar. It grew between 15 and 45 °C and tolerated up to 7 % NaCl (w/v). Strain CCBAU 05776T grew in media with pH 5.5 to 10 (optimal growth at pH 7.0–8.0). The predominant cellular fatty acids were iso-C15 : 0 (40.81 %) and C16 : 1ω7c alcohol (10.61 %). The predominant isoprenoid quinone was menaquinone 7 (MK-7). The cell-wall peptidoglycan contained meso-diaminopimelic acid. The major polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The DNA G+C was 40.8 mol% (T m). DNA–DNA relatedness of the novel isolate with B. muralis and B. simplex was 42.4 % and 32.7 %, respectively. Based upon the consensus of phylogenetic and phenotypic analyses, strain CCBAU 05776T represents a novel species within the genus Bacillus, for which the name Bacillus endoradicis sp. nov. is proposed. The type strain is CCBAU 05776T ( = LMG 25492T  = HAMBI 3097T).