Abstract

L-lactic acid production from soybean straw hydrolysate using alginate-immobilised Lactobacillus casei

Author(s): Juan Wang, Zhong Xu, Qunhui Wang, Wenyu Zhang, Yongzhen Ji, Wei Yin

The effect of temperature, inoculum size, pH, initial reducing sugar concentration and Ca-alginate bead size on L-lactic acid production using immobilised Lactobacillus casei was investigated to promote the production of L-lactic acid from soybean straw enzymatic hydrolysate. The optimal conditionswere as follows: temperature, 30°C; inoculum size, 10%; and pH, 5.5. L-lactic acid yield increased gradually as the reducing sugar concentration increased. The size of the Ca-alginate beads had no significant effect on lactic acid production, and the immobilised cell could be continuously used formore than 10 times. Immobilised cellswere found to perform better than free cells in lactic acid production. The results indicated the feasibility of producing L-lactic acid using soybean straw enzymatic hydrolysate and provided a novel utilisation of soybean straw resources.