关键词: 固定化德氏乳酸杆菌, 纤维素水解液, 乳酸, 发酵

Abstract: Cellulosic material is the most abundant renewable carbon source in the world.Using cellulosic hydrolysate instead of starch for lactic acid production is meaningful.Lactobacillus delbrueckii cells were immobilized by entrapped into calcium alginate gels.The immobilized cells were quite stable,and could utilize cellulosic hydrolysate to produce lactic acid efficiently.Optimum fermentation temperature was 48℃,and wheat bran hydrolysate could promote the production of lactic acid obviously.Comparing with free cells,the fermentation term of immobilized cells was (shortened),and the yield of lactic acid could reach 90.1% on cellulosic hydrolysate from corn cob.During 16 repeated batch fermentation processes,average yield of lactic acid was 88.6% using the immobilized cells on cellulosic hydrolysate.Continuous fermentation process was carried out in a 250 mL column reactor with immobilized cells on cellulosic hydrolysate,the lactic acid yield and production efficiency under 0.12 h^-1 dilution rate were 80.2% and 4.97 g/(L·h),respectively.

Key words: immobilized Lactobacillus delbrueckii, cellulosic hydrolysate, lactic acid, fermentation