碱预处理玉米芯生物转化L-乳酸  

Production of L-Lactic Acid by Bioconversion of Alkali Pretreated Corncob

作　　者：张丽[1,2] 陈晓佩[1,2] 李鑫[1,2] 余世袁[1,2] 勇强[1,2] 

机构地区：[1]南京林业大学林业资源高效加工利用协同创新中心,江苏南京210037 [2]南京林业大学化学工程学院,江苏南京210037

出　　处：《林产化学与工业》2016年第2期51-56,共6页Chemistry and Industry of Forest Products

基　　金："十二五"国家科技支撑计划资助(2015BAD15B09);江苏高校自然科学研究重大项目(14KJA220003);江苏省普通高校研究生科研创新计划项目(CXZZ13_0544)

摘　　要：玉米芯经碱预处理后,采用米根霉对其发酵制备L-乳酸,同时考察分步糖化发酵(SHF)和同步糖化发酵(SSF)两种工艺。实验结果表明,水洗碱预处理玉米芯酶水解性能优于未水洗碱预处理玉米芯,水洗过程可显著提高米根霉发酵性能。分步糖化发酵工艺下,米根霉于40℃下发酵48 h,可将含有31.84 g/L葡萄糖、6.38 g/L木糖的酶解液转化为14.65 g/L的L-乳酸,L-乳酸得率为0.29 g/g(以绝干物料计,下同);同步糖化发酵工艺下,米根霉40℃发酵36 h将底物质量浓度为50 g/L的水洗碱预处理玉米芯高效转化为L-乳酸,L-乳酸得率为0.44 g/g。Corncob pretreated by alkali was used as renewable raw material for L-lactic acid production by Rhizopus oryzae. The processes of separate saccharification and fermentation（ SHF） and simultaneous saccharification and fermentation（ SSF） were studied. The results showed that the enzymatic hydrolysis performance of washed alkali pretreated corncob was better than that of unwashed alkali pretreated corncob. Water-washing process could enhance the fermentability of alkali pretreated corncob. The washed alkali pretreated corncob hydrolysate with 31. 84 g / L glucose and 6. 38 g / L xylose was converted to 14. 65 g / L of L-lactic acid which was equivalent to a yield of 0. 29 g / g dry biomass with SHF process at 40 ℃ for 48 h. In contrast,a higher L-lactic acid yield（ 0. 44 g / g dry biomass） was achieved at 40 ℃ for 36 h,when the substrate concentration of 50 g / L washed alkali pretreated corncob was used in SFF process.

关 键 词：米根霉 碱预处理玉米芯 L-乳酸 分步糖化发酵 同步糖化发酵 

分 类 号：TQ35[化学工程]