Characterization of Microbial Inoculants and its Different Formulation For Mass Production

Biofertilizers are alternative source of nutrient inputs in sustainable agriculture. Plant growth promoting microorganisms such as Rhizobium spp. and Bacillus spp. can be used as biofertilizers. In our present study, different Rhizobium and Bacillus isolates were screened for the selection of suitable medium for its maximum growth at different incubation period. The Growth pattern of Rhizobium isolates were evaluated in two different media viz. Nutrient broth and YEM broth while of Bacillus spp. on four different media viz. LGD broth, Nutrient broth, NYSM broth and BMS broth. Our results revealed that the YEM broth supported better growth of Rhizobium isolates than Nutrient broth. However, the maximum growth of Bacillusspp. was observed in BMS broth while least in LGD broth at O.D 620nm after 72 hrs.But there was the problem to take optical density because of formation of black pellicle in BMS media byBacillus spp. Therefore, we conclude that NYSM media is best media for the growth of Bacillus spp. Rhizobium and Bacillus spp. were evaluated for IAA production. Bacillus spp. was found more efficient than Rhizobium in terms of IAA production. For different carrier materials like Charcoal, Fly-ash and additives such as Glycerol and Trehalose were used over a period of 15 days of storage to assess the survivability of different Rhizobium and Bacillus isolates. Based on the finding of the study, the charcoal can be used as an alternate carrier material to prepare the microbial inoculants. However, the liquid inoculants were found to be better in supporting the population of inoculants than the carrier based inoculants.