A comparative study of azotobacter spp. from various localities of Aurangabad district (M.S.)

Present investigation was carried out to study Azotobacter spp. Collected from Rhizosphere of various crops from Aurangabad district (M.S.). Twelve Rhizosphere samples were collected from various localities of the district and soil testing was done to determine pH, water holding capacity and moisture. After isolation of bacteria from Rhizosphere, biochemical tests were performed to study their characters. Bacterial strains collected from various locations were named as Strain 1 to Strain 12. Out of these strains 3, 7 and11 did not show characters identical with Azotobacter; while other strains resembled Azotobacter spp. Cell size of Azotobacter ranged in between 1.05 to 2.00μm. Colonies were creamy white, circular, small to large sized, opaque with smooth margins. During biochemical tests, the test for citrate was negative, while it was positive for starch hydrolysis, catalase, indole production, urease and nitrate reduction. Azotobacter is widely used as bio-inoculants for wide variety of crops, and hence, it's morphological and biochemical study of Azotobacter spp. will be useful for further research.