Abstract
The phenomenon of flocculation in Azospirillum brasilense (MTCC-125) was studied under different combinations of carbon and nitrogen sources. Fructose and Potassium nitrate at a pH of 6.4 in the cultural medium favour a higher bio-floc production. The biofloc was studied for root adhesion and its survival efficiency in the rhizoplane and rhizosphere of certain crops such as sorghum and sunflower under dryland condition. It has been demonstrated that the flocculated cultures of Azospirillum were found to have maximum adhesion to the root surface and higher survival rate in the rhizoplane and rhizosphere under different moisture stressed conditions as compared to the log phase cells of Azospirillum.