Conversion of Agricultural Wastes to Lactic Acid by a Combination of Pentose-fermentative Lactic Acid Bacteria and Reversibly Soluble-insoluble Enzymes

1)利用纤维素酶制剂对脱木素稻草进行水解制得葡萄糖和木糖。从脱脂米糠中提取葡萄糖和阿拉伯糖的方法主要有淀粉酶和纤维素酶两种。2)筛选出一株木糖发酵乳酸菌，分别为痘苗乳杆菌、戊糖乳杆菌、戊糖小球杆菌和干酪肠球菌。3)在以木糖和葡萄糖为碳源的MRS发酵中，乳酸量没有增加。4)在未灭菌的米糠糖化发酵过程中，保持较低的pH值，可以选择性生长添加乳酸菌的鼠李糖乳杆菌。以脱脂米糠为原料，在pH为4.5的条件下同时糖化发酵，可生产出约30g/L的L乳酸。

1) Glucose and xylose were mainly obtained from delignified rice straw by hydrolysis using cellulase preparation. Glucose and arabinose were mainly obtained from defatted rice bran by hydrolysis using amylase and cellulase preparations.2) Lactobacillus vaccinostericus, Lactobacillus pentosus, Pediococcus pentosaceus, and Enterococcus casseliflavus were selected as a xylose-fermented lactic acid bacterium. More lactic acid was produced from MRS medium containing xylose by E. casseliflavus as compared with other lactic acid bacteria.3) The amount of lactic acid produced did not increase in a fermentation using MRS medium containing xylose and glucose as a carbon source and E. casseliflavus.4) The maintenance of pH at a low value in a simultaneous saccharification and fermentation of non-sterilized rice bran allowed the selective growth of Lactobacillus rhamnosus, a lactic acid bacterium added. About 30 g/L of L-lactic acid was produced from defatted rice bran in a simultaneous saccharification and fermentation in which the pH was kept at 4.5.