A novel highly boron tolerant bacterium, Bacillus boroniphilus sp nov., isolated from soil, that requires boron for its growth

Three strains of gram-positive, motile, rod-shaped and boron (B)-tolerant bacterium were isolated from naturally B containing soil of Hisarcik area in the Kutahya Province, Turkey. The strains, designated as T-14A, T-15Z(T) and T-17s, produced spherical or ellipsoidal endospores in a terminal bulging sporangium. The strains required B for the growth and can tolerate more than 450 mM B. These also tolerated up to 7.0% (w/v) NaCl in the presence of 50 mM B in agar medium but grew optimally without NaCl. The temperature range for growth was 16-37 degrees C (optimal of 30 degrees C), whereas the pH range was 6.5-9.0 (optimal of 7.5-8.5). The DNA G + C content was 41.1-42.2 mol% and the predominant cellular fatty acid was iso-C-15:0. The major respiratory quinone system was detected as MK-7 and the diamino acid of the peptidoglycan was meso-diaminopimelic acid. Based on phenotypic and chemotaxonomic characteristics, phylogenetic analysis of 16S rRNA gene sequences data and DNA-DNA re-association values, we concluded that the three strains belong to a novel species of the genus Bacillus, the type strain of which is T-15Z(T) and for which we proposed the name, B. boroniphilus sp. nov. (DSM 17376(T) = IAM 15287(T) = ATCC BAA-1204(T)).