Screening of rhizobacteria for pgpr and antagonistic activities isolated from medicinal plants

Rhizosphere soils from nine medicinal plants were used to identify the plant growth promoting ability of rhizobacteria. The bacterial isolates were purified and identified based on their morphological and biochemical characteristics. Altogether twenty nine bacterial species were identified belonging to seven genera (Staphylococcus, Micrococcus, Bacillus, Pseudomonas, Neisseria, Serratia, Streptococcus). All the isolates were identified up to genus level except the potential isolates. Results showed that the colonization of rhizobateria vary among the medicinal plants. The rhizobacterial isolates were screened for their plant growth promoting activity such as Ammonia, Indole acitic acid, Phosphate solubilization and Hydrogen cyanide production. Among the isolates Pseudomonas sp from Leucas aspera and Bacillus sp Cleome viscosa gave better result for almost all the test. However Bacillus sp effectively inhibited the fungal pathogen. Hence it was characterized through 16s r DNA sequencing and identified as Bacillus cereus NK2.