Optimization of lactic acid production by probiotic Bacillus coagulansusing cheap carbon source

In the present study, the effect of incubation temperature (40 to 60 °C), fermentation time (48 to 72 hours), concentrations of permeate (5-10percent) and vinasse (0 to 15percent) as fermentation variable on the production and productivity of lactic acid were studied using a Box-Behnken design. The results showed that all four independent variables had a significant effect on lactic acid production (p 0.05). Optimization by the desirability function method showed that the maximum production of lactic acid by B. coagulance was at 41 °C, fermentation time of 63 hours, permeate and vinasse as fermentation medium was equal to 8.5 and 10percent (w/v). Thelactic acid production in these conditions was 10.23 g/L. Finally, an HPLC analysis was used to confirm the amount of lactic acid production.