Development of bioprocess for high density cultivation yield the probiotic Bacillus coagulans and its spores

Abstract

Bacillus coagulans is a spore forming lactic acid bacterium. Spore forming bacteria, have been extensively studied and commercialized as probiotics. Probiotics are produced by fermentation technology. There is a limitation to biomass produced by conventional modes of fermentation. With the great demand generated by range of probiotic products, biomass is becoming very valuable for several pharmaceutical, dairy and probiotic companies. Thus, there is a need to develop high cell density cultivation processes for enhanced biomass accumulation.

The bioprocess development was carried out in 6.6l bench top lab scale fermentor. Four different cultivation strategies were employed to develop a bioprocess for higher growth and sporulation efficiencies of probiotic B. coagulans. Batch fermentation of B. coagulans yielded 18gl^-1 biomass (as against 8.0gl^-1 productivity in shake flask) with 60% spore efficiency. Fed batch fermentation was carried out for glucose, which yielded 25gl^-1 of biomass. C/N ratio was very crucial in achieving higher spore titres. Maximum biomass yield recorded was 30gl^-1, corresponding to 3.8x10¹¹ cells ml^-1 with 81% of cells in sporulated stage.The yield represents increment of 85 times the productivity and 158 times the spore titres relative to the highest reported values for high density cultivation of B. coagulans.