Statistical optimization of simultaneous saccharification and l(+)-lactic acid fermentation from cassava bagasse using mixed culture of lactobacilli by response surface methodology

Abstract Optimization of five process parameters (concentrations of cassava bagasse, enzyme, yeast extract, NH 4 Cl and inoculum) was attempted using a Box-Behnken design for the optimal production of l (+)-lactic acid by a mixed culture of Lactobacillus casei and Lactobacillus delbrueckii by simultaneous saccharification and fermentation. Maximum lactic acid yield of 81 g/L was obtained when 15% (w/v) cassava bagasse treated with 12.5 mL/L enzyme mixture was supplemented with 7.5 g/L yeast extract and 3 g/L NH 4 Cl and inoculated with 3 × 10 10  CFU/L of lactobacilli and incubated for 60 h at 37 °C as static culture.