摘要
为了提高纤维素乙醇的生产效率,对高效产纤维素酶曲霉W-10的产酶条件进行优化,利用其发酵所得的粗酶液对预处理后的水稻秸秆粉进行酶解,并用酿酒酵母通过同步糖化发酵(simultaneous saccharification and fermentation,SSF)工艺生物转化纤维素乙醇.首先通过定时取样测定还原糖量,研究不同底物浓度、不同表面活性剂添加量、纤维二糖酶的协同作用等因素对酶解过程的影响.然后利用所得优化后的酶解条件进行同步糖化实验,研究不同的发酵温度、发酵时间、初始pH值等影响因素对同步糖化发酵乙醇的影响.结果表明,当底物浓度为80 g/L、表面活性剂吐温-80添加浓度为5 g/L、酶解体系外纤维二糖酶补加量为166.67 nkat/g时,粗酶液的酶解率最高;在35℃的培养温度、初始pH值为5的条件下发酵4 d时,发酵液中乙醇含量最高,乙醇得率可达0.43 g/g(底物干重).优化高效产纤维素酶曲霉W-10酶解水稻秸秆的反应条件,可促进纤维素乙醇生物转化技术的发展,有利于可再生的清洁能源生物乙醇的商业化生产和应用.
Biotransformation of bioethanol was innovatively processed with crude enzyme to hydrolyse rice straw from a high-yield cellulase-producing Aspergillus W-10 and by simultaneous saccharification and fermentation(SSF)with Saccharomyces cerevisiae.Hydrolysis and saccharification of pretreated rice straw by crude enzyme with cellulase and cellobiase was measured at regular sampling of reducing sugar.Meanwhile,the impacts of substrate concentration,the amount of surfactant and synergism of cellobiase on hydrolysis process were studied.Then,the effects of fermentation temperature,fermentation time and initial pH value on the SSF were also explored on the bassis of the optimized hydrolysis conditions.The results show that when the concentration of substrate was 80 g/L,the concentration of surfactant Tween-80 was 5 g/L,and the amount of cellobiase was 166.67 nkat/g,the highest efficiency of hydrolysis of crude enzyme was observed.When the fermentation temperature was 35℃,the fermentation time was 4 d,and the initial pH value was 5,the concentration of ethanol in fermentation broth was the highest,reaching 0.43 g/g(dry weight of substrate).The optimization of the reaction conditions of high yield cellulase-producing Aspergillus W-10 can promote the bioconversion technology development of lignocellulosic ethanol,which is beneficial to the large-scale commercial production and application of bioethanol as a renewable clean energy.
作者
刘洋
邱忠平
孟涛
龚正君
王东梅
樊超
LIU Yang;QIU Zhongping;MENG Tao;GONG Zhengjun;WANG Dongmei;FAN Chao(School of Geoscience and Environmental Engineering,Southwest Jiaotong University,Chengdu 610031,China;School of Life Science and Engineering,Southwest Jiaotong University,Chengdu 610031,China)
出处
《西南交通大学学报》
EI
CSCD
北大核心
2020年第1期225-230,共6页
Journal of Southwest Jiaotong University
基金
国家自然科学基金(21776230)
四川省重点研发项目(19ZDYF0467,2015NZ0097)
关键词
产纤维素酶曲霉
纤维素
生物乙醇
酶解
同步糖化发酵
cellulase-producing Aspergillus
lignocellulose
bioethanol
hydrolyse
simultaneous saccharification and fermentation
