High β-Glucosidase Secretion in Saccharomyces cerevisiae Improves the Efficiency of Cellulase Hydrolysis and Ethanol Production in Simultaneous Saccharification and Fermentation
High β-Glucosidase Secretion in Saccharomyces cerevisiae Improves the Efficiency of Cellulase Hydrolysis and Ethanol Production in Simultaneous Saccharification and Fermentation
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DOI：
10.4014/jmb.1305.05011
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发表时间：
2013-11-01
影响因子：
2.8
通讯作者：
Bao, Xiaoming
中科院分区：
文献类型：
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作者：
Tang, Hongting;Hou, Jin;Bao, Xiaoming
从木质纤维素生产生物乙醇被认为是一种可持续的生物燃料供应。然而，低的纤维素水解效率限制了纤维素乙醇的生产。纤维素受到主要终产物纤维二糖的强烈抑制，这可以通过添加β-葡萄糖苷酶来缓解。在本研究中，三种不同来源的β-葡萄糖苷酶分别在酿酒酵母中表达，其中扣囊拟青霉的β-葡萄糖苷酶活性最高（5.2。U/m1）。重组菌经S.在葡萄糖中，扣囊霉β-葡萄糖苷酶能以与对照菌株相似的比生长速率代谢纤维二糖。该重组菌在利用β-葡萄糖苷酶活性较低的里氏木霉纤维素进行纤维素同步糖化发酵时，表现出较高的水解效率。最终乙醇浓度为110%（使用Avicel）和89%（使用酸预处理的玉米芯）高于对照菌株。这些结果证实了β-葡萄糖苷酶在重组S.酿酒酵母用于增强纤维素乙醇转化。
Bioethanol production from lignocellulose is considered as a sustainable biofuel supply. However, the low cellulose hydrolysis efficiency limits the cellulosic ethanol production. The cellulose is strongly inhibited by the major end product cellobiose, which can be relieved by the addition of beta-glucosidase. In this study, three beta-glucosidases from different organisms were respectively expressed in Saccharomyces cerevisiae and the beta-glucosidase from Saccharomycopsis fibuligera showed the best activity (5.2. U/m1). The recombinant strain with S. fibuligera beta-glucosidase could metabolize cellobiose with a specific growth rate similar to the control strain in glucose. This recombinant strain showed higher hydrolysis efficiency in the cellulose simultaneous saccharification and fermentation, when using the Trichoderma reesei cellulose, which is short of the beta-glucosidase activity. The final ethanol concentration was 110% (using Avicel) and 89% (using acid-pretreated corncob) higher than the control strain. These results demonstrated the effect of beta-glucosidase secretion in the recombinant S. cerevisiae for enhancing cellulosic ethanol conversion.