Saccharification of Delignified Sugarcane Bagasse for Lactic Acid Fermentation Using <i>Lactobacillus</i> sp.

Abstract

Delignified sugarcane bagasse (SCB) by solvent extraction was carried out at moderate condition (90°C, 4 h) in the presence of acid catalyst. To investigate the dissolution of lignin into solvent, different solvents were utilized during lignin extraction process. Delignified SCB was further hydrolyzed by cell wall degrading enzyme complexes prior to sugar determination. The results showed that n-butanol was the most promising solvent enhancing lignin dissolution which in turn led to highest yield of glucose (63.1% based on treated SCB) and no xylose was detected in hydrolysate. The lignin extraction by n-butanol in the presence of H2SO4 and subsequent saccharification process were then scaled up for lactic acid production. The maximum lactic acid was obtained at 25.7 ± 0.2 g/l from L. casei fermentation after 96 hours when sugarcane bagasse hydrolysate containing 25.6±1.4 g/l initial glucose concentration was used as substrate.