研究了以纤维为原料，采用乳杆菌突变体从葡萄糖和木糖发酵制备光学纯D-乳酸的生产工艺。用脱木素后的阔叶木浆（加入量5%～15%）为原料，在同步糖化发酵法（简称S S F）下处理72h，可使乳酸浓度达到55.2～84.6g/l，产酸速率为1.77～2.61g/(l.h)。预先对浆料进行短时间的（≤10m i n）研磨，能有效抑制甲酸副产物的产生，从而促进酶在发酵温度下对浆料含量较高体系的糖化水解。浆料经过短时间研磨预处理后，采用SSF过程发酵，能够使乳酸浓度达到102.3g/l，光学纯度为99.2%，得率为0.879g（相对于每克糖）。因此，本研究表明采用乳杆菌突变体制备高浓度D-乳酸是可行的。%This study focused on the process development for the D-lactic acid production from cellulosic feedstocks using the Lactobacillus plantarum mutant, genetically modified to produce optically pure D-lactic acid from both glucose and xylose. The simultaneous sacchariifcation and fermentation (SSF) using deligniifed hardwood pulp (5%~15% load) resulted in the lactic acid titers of 55.2~84.6g/L after 72h and increased productivities of 1.77~2.61g/(L·h). To facilitate the enzymatic sacchariifcation of high-load pulp at a fermentation temperature, short-term (≤10min) pulverization of pulp was conducted, leading to a signiifcantly improved sacchariifcation with the suppressed formation of formic acid by-product. The short-term milling followed by SSF resulted in a lactic acid titer of 102.3g/L, an optical purity of 99.2%, and a yield of 0.879g/g-sugars without fed-batch process control. Therefore, the process presented here shows promise for the production of high-titer D-lactic acid using the L. plantarum mutant.
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