In vitro evaluation of Antibiotic resistance and plant growth promoting traits in NR5
B. mycoides NR5 was tested against 20 antibiotics and was found resistant to 16 antibiotics. NR5 was found to be highly resistant recorded against Amikacin, Ciprofloxacin, Co-Trimoxazole, Erythromycin, Gentamicin, Nalidixic Acid, Netillin, Nitrofurantoin, Norfloxacin, and Tobramycin, moderately resistance to Cefadroxil, Ceftriaxone, Cloxacillin, and Vancomycin, and low resistance to Cefoperazone and Ceftazidime. There was no growth inhibition in Ampicillin, Amoxycillin Chloramphenicol and Penicillin (Table S2).
B. mycoides NR5 was evaluated for having plant growth promoting attributes such as phosphate solubilization, IAA production, siderophore, ammonia production and nitrate reduction. The qualitative test for P-solubilization was found positive, and the subsequent quantitative estimation of B. mycoides NR5 was calculated as 115.51±0.47 µgL-1. The NR5 was also found to possess siderophore production ability and the index for production of siderophore was calculated to be 28.61% unit (Table S3). Similarly, ammonia production, which is also an important PGP trait, was also high and the bacterium was a good ammonia producer. NR5 was also found positive for nitrate reduction assay but the efficiency was not high.