Efficient co-production of xylo-oligosaccharides and probiotics from corncob by combined lactic acid pretreatment and two-step enzymatic hydrolysis.

Lactic acid (LA) is efficient in xylo-oligosaccharides (XOS) production from poplar. However, the role of LA in XOS production from corncob has not been carefully elucidated, and the co-production of probiotics of Bacillus subtilis from corncob residue has not been reported. In this study, LA pretreatment was combined with enzymatic hydrolysis to produce XOS and monosaccharides from corncob. An XOS yield of 69.9% was obtained from corncob by combining 2% LA pretreatment and xylanase hydrolysis. Yields of 95.6% glucose and 54.0% xylose were obtained from corncob residue via cellulase, and the resulting cellulase hydrolysate was used to culture Bacillus subtilis YS01. The resulting viable count of the strain was 6.4×10 CFU/mL, and the glucose and xylose utilization were 99.0% and 89.8%, respectively. This study demonstrated a green, efficient, and mild process for producing XOS and probiotics from corncob by combining LA pretreatment and enzymatic hydrolysis.