Isolation and characterization of bacterial endophytes from the roots of Cassia tora L

In the present investigation, five endophytic bacterial strains isolated from the roots of Cassia tora L. were identified as Bacillus subtilis, Agrobacterium tumefaciens, Bacillus sp., Pseudomonas putida, and Pseudomonas sp. based on biochemical characteristics as well as 16S rRNA gene sequencing. Isolates were screened for plant growth promoting traits, antibacterial activity, antifungal activity, antibiotic sensitivity, and salinity tolerance. The majority of the endophytic strains produced phytohormone indole acetic acid (IAA), ammonia, and also solubilized phosphate. Siderophore and HCN production were observed in A. tumefaciens, P. putida, and Pseudomonas sp. The antibiotic sensitivity profile indicated that the isolates were resistant to chloramphenicol, while highly susceptible to neomycin and streptomycin. Bacterial endophytes gave a definite stamp on their antibacterial activity against Escherichia coli and Klebsiella pneumoniae and antifungal activity against Pythium ultimum, Aureobasidium pullulans, and Alternaria alternata. Pseudomonas sp. showed maximum salt tolerance (6 % NaCl) contrary to A. tumefaciens that was least tolerant.