tailieunhanh - Characterization and screening of native isolates of PSB and Azotobacter under in vitro conditions

The present study was conducted at Department of Agriculture Microbiology, College of Agriculture, IGKV, Raipur, . during the year 2018-19 to characterize and screen different native isolates of PSB and Azotobacter. 14 microbial isolates were biochemically characterized and screened under in-vitro conditions for their plant growth promoting properties. Among 14 tested isolates Azoto-B-44, Azoto-146, Azoto-B-126, PSB-S-88, PSB-H-27, PSB-S-170, PSB-S-71, PSB-H-5, PSB-S-162 were shown positive results for TSI and Citrate test. PSB-172 and PSB-S-64 were shown positive for MR test and PSB-S88, PSB-S-71, PSB-H-5, PSB-S-165 and PSB-S-162 were found positive for Gelatin liquefaction test. Rest of all isolates was negative towards above tests. All the isolates were taken for their antibiotic susceptibility study. Some isolates were found susceptible for Tetracycline (30mcg) and streptomycin (10mcg). In N-fixation study of Azotobacter isolates Azoto-B-126 found higher N-fixer, it fixed N/gm of sucrose. Azoto-123, Azoto-146 and Azoto-B-126 found significantly superior and at par for N-fixing capacity over Azoto-B-44. Ten isolates of PSB were screened for their P-solubilizing capacity. PSB-H-5 was found highest P-solubilizer ( µg/ml), however all the isolates found significantly superior for P-solubilizing capacity over control. All the PSB isolates were also tested for their solubilizing efficiency of phosphorus in the form of solubilization zone. PSB-H-27 was found highest solubilization efficiency with solubilization zone of 14 mm diameter, however it found at par with PSB-S-162, PSB-S-165, PSB-S-71, PSB-H-5 and PSB-S-170. | Characterization and screening of native isolates of PSB and Azotobacter under in vitro conditions