利用木霉与根霉两步发酵秸秆制备L-乳酸研究  

Two-step fermentation of crop straw by using Trichoderma viride and Rhizopus oryzae for producing L-lactic acid

作　　者：李兴江[1] 郑志[1] 姜绍通[1] 潘丽军[1] 

机构地区：[1]合肥工业大学生物与食品工程学院,合肥230009

出　　处：《菌物学报》2009年第3期445-450,共6页Mycosystema

基　　金：国家科技支撑计划(No.2007BAD34B01);安徽省自然科学基金(No.070411024;090411010);合肥工业大学基金(No.073002F)

摘　　要：以秸秆为原料进行生物转化大量制备有机酸意义重大。在秸秆汽爆法预处理的基础上,以绿色木霉为菌种转化制备秸秆糖,对降解单糖接种米根霉进行二次发酵制备L-乳酸。试验结果表明,第一步绿色木霉固态培养制备纤维素酶时,控温30℃、通气0.12L/(L·min)、发酵40h后制备干曲,后按10g干曲/L汽爆液的配比进行55℃酶解36h,五、六碳糖累积浓度达到86g/L。第二步米根霉发酵时,控制温度32℃、通气0.4L/(L·min)、转速450r/min,发酵48h,最终产L-乳酸累积浓度为81.6g/L。秸秆制备L-乳酸的两步发酵法发酵工艺具有推广价值。Crop straw was pretreated by steam-exploded method, and Trichoderma viride was used for degradation of crop straw in the first-step fermentation, then Rhizopus oryzae was used for producing L-lactic acid in the second-step fermentation. The optimal condition for the first-step fermentation was as follows： fermentation temperature of 30℃, aeration rate of 0.12L/（L.min） for 40 hours, including pentose and hexose sugar concentration of about 86g/L when 10g dry biomass from the first-step fermentation was used for the degradation of 1L hydro lyte. The yield of L-lactic acid was about 81.6g/L when the second-step fermentation condition was as follows： temperature of 32℃, aeration rate of 0.4L/（L-min）, rotation rate of 450r/min and fermentation period of 48 hours. It was concluded that the two-step fermentation technics for the production of L-lactic acid from crop straw was worthy to be developed on a large scale.

关 键 词：绿色木霉 米根霉 发酵工艺 

分 类 号：Q93[生物学—微生物学]