Development of a Cost-effective Medium for the Mixed Fermentation of Paenibacillus durus, Paenibacillus glucanolyticus and Bacillus megaterium

In the recent years, plant growth promoting rhizobacteria (PGPR) are gaining much importance due to the drastic effects of chemical fertilizers. Growing these PGPR as an axenic culture is time consuming and also increases the production cost. The present study aims in the development of cost effective medium for the mixed fermentation of 3 PGP isolates i.e., Paenibacillus durus, Paenibacillus glucanolyticus and Bacillus megaterium and further optimization of the fermentation parameters. Among the 4 media developed, MC2 showed high CFU counts i.e., 1.2x109/ml in Paenibacillus durus, 3.4x109/ml in Paenibacillus glucanolyticus, 2.1x109/ml in Bacillus megaterium. Sucrose optimization studies showed good results at 15 g/L and yeast extract optimization studies showed high microbial load at 2 g/L. Fermentation parameters were optimized viz. incubation temperature 30oC, pH 7.0 and inoculum percentage 8%. A batch trial was conducted by taking the optimized nutrient and fermentation parameters which showed good results in P. durus (final broth 6.2x109/ml, cell biomass 2.8x1011/g), P. glucanolyticus (final broth 7.6x109/ml, cell biomass 3.1x1011/g) and Bacillus megaterium (final broth 4.4x109/ml, cell biomass 2.3x1011/g). Based on the above results, it can be stated that the optimized MC2 medium can be effectively used in the mixed fermentation in the industries.

Pelapudi Pitchaiah1, Ch. Sasikala2 and Ganti Swarnabala*3 Click here to download file

Research Article | Published online : 24-Jun-2022