OPTIMISATION OF MEDIA FOR PRODUCTION OF COST- EFFECTIVE RHIZOBIUM [BIOFERTILIZER]

Rhizobium is a soil habitat, gram negative bacterium associated symbiotically with the roots of leguminous plants. Rhizobium helps in the process of nitrogen fixation. Screening and selecting the most effective strain play a key role in the process of biological nitrogen fixation. The present work was undertaken to bring into light different characteristics, growth, isolation, and secretion of rhizobial strains (bradyrhizobium). These are found in the root region of the leguminous plants where it forms nodules and fix nitrogen. The study revealed that the species used was non-spore forming, rod-shaped, motile, aerobic, gram- negative soil bacterium. These rod-shaped bacteria are 0.8um in diameter and 2um in length, and often have flagellae. These species are non-pathogenic to humans. The rhizobium bacteria were grown on three different types of medias namely – nutrient broth, CRYEMA( Congo Red Yeast Extract Mannitol Agar), and modified media containing jaggery. The common ingredients of the culture media included Peptone, Meat Extract, Mineral Salts, Carbohydrates and Water. Growth analysis, substrate estimation and biomass estimation was done and yield coefficient was calculated. Rhizobium was then applied as a biofertilizer for good improvement in plant growth and yield.