Bacillus subtilisStrains Isolated from Cocoa Trees (Theobroma cacao L.) Rhizosphere for their use as Potential Plant Growth Promoting Rhizobacteria in Cote d'Ivoire

Plant growth promoting rhizobacteria (PGPR) are important for agriculture through their activity in stimulating and facilitating plant growth. The rhizobacteria were screened for molecular characterization and followed by their indole acetic acid (IAA) production, phosphate solubility, antibiosis activity. In this study, 162 soil samples were collected from the cocoa rhizosphere to isolateBacillus subtilisstrains using Mossel agar medium with an additional egg yolk and identified by sequencing theytcPgene. The ability of each strain to form biofilms was obtained in a tube. Indole-3-acetic acid (IAA) production was estimated in Yeast Peptone Dextrose (YPB) broth. Phosphates were solubilized by each strain on Pikovskaya agar medium. The detection of lipopeptide genes using the molecular method has established the possession of isolates by antimicrobial genes. Fifty (50)B. subtilisstrains were isolated and identified using theytcPgene. Ninety percent (90%) of the strains were able to form a biofilm. All isolates produced an IAA. Forty (40 (80%)) ofB. subtiliswere solubilized phosphate with phosphate solubilizing index (PSI) of 0 to 97.33 +/- 0.70%. Of allB. subtilisstrains, 45 (90%) have thesrfAAgene, 19 (38%) have thefenDgene and 12 (24%) have theituCgene.B. subtilisstrains from cocoa rhizosphere would be beneficial for agricultural production by their PGPR activities.