Bacillus cabrialesii subsp. cabrialesii subsp. nov. and Bacillus cabrialesii subsp. tritici subsp. nov., plant growth-promoting bacteria and biological control agents isolated from wheat ( Triticum turgidum subsp. durum ) in the Yaqui Valley, Mexico

Strain TSO2 T , a plant growth-promoting rhizobacteria and biological control agent, was isolated from wheat rhizosphere sampled from the Yaqui Valley in Mexico. The strain was identified using a polyphasic approach. Based on its analysis of the full-length 16S rRNA gene, strain TSO2 T was assigned to the genus Bacillus , which was supported by morphological and metabolic traits, such as Gram-positive staining, rod shape, spore formation, strictly aerobic metabolism, catalase-positive activity, starch, and casein hydrolysis, reduction of nitrate to nitrite, growth in presence of lysozyme and 2 % NaCl, citrate utilization, growth at pH 6.0, acid production from glucose and indole production from tryptophan. Additionally, strain TSO2 T possesses swarming motility, presenting a featureless mat pattern that can cover the whole petri dish. The whole-genome phylogenetic relationship analysis elucidated that strain TSO2 T is closely related to Bacillus cabrialesii TE3 T . The maximum values for average nucleotide identity (ANI) and in silico DNA–DNA hybridization from the genome-to-genome distance calculator (GGDC) were 97 and 73.4 %, respectively, related to Bacillus cabrialesii TE3 T , where both ANI and GGDC values were barely above the species delimitation threshold, but below the subspecies limit. Also, strain TSO2 T showed the ability to produce a fatty acid (C 18 : 0 ) that is not present in closely related Bacillus species. These results provide evidence that strain TSO2 T is a novel subspecies of the species Bacillus cabrialesii , for which the name Bacillus cabrialesii subsp. tritici subsp. nov. is proposed. The type strain of Bacillus cabrialesii subsp. tritici subsp. nov. is TSO2 T (CM-CNRG TB52 T =LBPCV TSO2 T ). The description of this novel subspecies automatically creates the subspecies Bacillus cabrialesii subsp. cabrialesii subsp. nov. for which the type strain is TE3 T (CM-CNRG TB54 T =CCStamb A1 T ).