Investigation of Indole Acetic Acid Production Potential of Azotobacter Chroococcum Using Wheat Coleoptile Bioassay

Azotobacter chroococcum was isolated from the garden soil in Jensen’s media. Morphological characterization and biochemical tests were done for confirmation. Using Indole Acetic Acid as the standard, auxin production potential of Azotobacter chroococcum was analysed using bioassay method involving wheat (Triticum durum var dara) coleoptile elongation in the culture filtrate. A positive moderate correlation of 0.44 was obtained between the coleoptile length and Indole Acetic Acid standard solutions. The highest amount of Auxin production by Azotobacter chroococcum was observed after 48 hrs of incubation, the effect exerted by the diluted culture filtrate being close to the effect of nearly optimal concentration of 10^-4 to 10^-5 mol/litre. In conclusion, Azotobacter chroococcum appears to be an ideal soil microorganism for high level of Indole Acetic Acid production. The details of the experiment can be utilized for the scaling up of Indole Acetic Acid production which can be commercially utilized for plant growth.