Simultaneous detoxification, saccharification and co-fermentation of oil palm empty fruit bunch hydrolysate for l-lactic acid production by Bacillus coagulans JI12

• Native detoxification of furfural by Bacillus coagulans JI12.
• Simultaneous detoxification, saccharification & co-fermentation of lignocellulose.
• Fermentation at 50 °C and pH 5.5 without sterilizing the medium.
• Lactic acid productivity was as high as 3.4 g/L/h.

Bacillus coagulans JI12 was used to produce l-lactic acid from both cellulose and hemicellulose sugars of oil palm empty fruit bunch hydrolysate at 50 °C without sterilization prior to fermentation. In fermentation of mixed glucose and xylose (10 g/L:100 g/L or 50 g/L:53 g/L), both sugars were simultaneously converted to l-lactic acid. B. coagulans JI12 was tolerant against up to 4 g/L of furfural and 20 g/L of acetate and able to metabolize furfural to 2-furoic acid. After acid hydrolysis, both the hemicellulosic and cellulosic fractions of oil palm empty fruit bunch were fermented to lactic acid in a simultaneous detoxification, saccharification and co-fermentation process supplemented with 25 FPU Cellic® CTec2 cellulase per g cellulose, yielding 80.6 g/L of lactic acid with a productivity of 3.4 g/L/h. Neither pre-detoxification nor separation of fermentable sugars from lignin was required. These results indicate that B. coagulans JI12 is a promising strain for l-lactic acid production from lignocellulosic biomass.