Bacillus cabrialesii sp. nov., an endophytic plant growth promoting bacterium isolated from wheat (Triticum turgidum subsp. durum) in the Yaqui Valley, Mexico

Strain TE3(T), an endophytic plant growth promoting bacterium, was isolated from wheat (Triticumturgidum subsp. durum) sampled in the Yaqui Valley, Mexico. Biochemical, phenotypic and genotypic approaches were used to clarify the taxonomic affiliation of this strain. Based on analysis of its full-length 16S rRNA gene, strain TE3(T) was assigned to the genus Bacillus (similarity >= 98.7 %). This finding was supported by morphological and metabolic characteristics, such as rod shape, strictly aerobic metabolism, spore formation, Gram-positive staining, catalase-positive activity, reduction of nitrate to nitrite, starch and casein hydrolysis, growth in presence of lysozyme and 2% NaCl, citrate utilization, growth pH from 6.0 to 8.0, and acid and indole production from glucose and tryptophan, respectively. The whole-genome phylogenetic relationship showed that TE3(T) formed an individual Glade with Bacillus tequilensis KCTC 13622(T), distant from that generated by all Bacillus subtilis subspecies. The maximum values for average nucleotide identity and in silico DNA-DNA hybridization were 93.85 and 54.30 %, respectively, related to Bacillus subtilis subsp. inaquosorum KCTC 13429(T). Analysis of its fatty acid content showed the ability of strain TE3(T) to bio-synthetize fatty acids that are not present in closely related Bacillus species, such as C-12:(0), C-12(:0) 20H, C-12(:0) 30H, C-17:0, iSO-C-17:0 30H and C-18:1 omega 9c. These results provide evidence that strain TE3(T) is a novel species of the genus Bacillus, for which the name Bacillus cabrialesii sp. nov. is proposed. The type strain of Bacillus cabrialesii is TE3(T) (CM-CNRG TB54(T) =CCStamb A1(T)).