Biochemical and molecular characterization of different bacillus sp. from the rhizosphere soil of ocimum basilicum

Ocimum basilicum commonly known as Basil is one of the promising herb with important multiple medicinal properties. In the present study, Bacillus sp. possessing multiple plant growth promoting activities was isolated from the rhizospheric soil of Ocimum basilicum collected from Gandhi Krishi Vigyan Kendra, University of Agricultural Sciences, Bangalore, on Luria Bertini media. In Biochemical characterization, Plant Growth Promoting Rhizobacteria (PGPR) – Bacillus sp. was screened for their plant growth promoting activities like phosphate solubilisation, production of indole acetic acid (IAA), ammonia, hydrogen cyanide (HCN), catalase, cellulase, biofilm, siderophore and organic acid. Further, species level identification was done by performing specific tests like Tyrosine agar test and growth on 3%, 5% and 10% Nacl was checked. These isolates also showed heavy metal tolerance. Different Bacillus species like Bacillus amyloliquefaciens, Bacillus cereus, Bacillus megaterium, and Bacillus sonorensis were identified by doing comparative study using biochemical characterization. From their PGPR activity, it was concluded that Bacillus cereus showed maximum amount of PGPR traits, Bacillus sonorensis showed optimum and Bacillus amyloliquefaciens showed minimum amount of PGPR traits, therefore, Bacillus cereus is the best plant growth promoting rhizobacteria (PGPR) with maximum PGPR traits. In Molecular characterization, 8 Bacillus sp. isolates having multiple plants growth promoting activities was selected and genomic DNA was isolated from bacterial cultures. DNA samples from this different Bacillus species were subjected to RAPD analysis to differentiate them at the species level and the RAPD primer OPG-8 (5/-TCACGTCCAC-3/) was used for amplifications. The expected ladder was not observed in the result, instead single amplicon of each isolate were observed therefore, this primer cannot be used for molecular characterization of different Bacillus species. Further analysis using different RAPD primers should be tested for ladder formation or molecular characterization.