过表达分支酸歧化酶编码基因ARO7对酿酒酵母抑制物耐受性的影响  

Effect of overexpression of chorismate mutase encoding gene AR07 on the inhibitor tolerance of Saccharomyces cerevisiae

作　　者：张明明[1] 万青青[2] 张克俞 熊亮[1] 白凤武[1,2] 赵心清[2] 

机构地区：[1]大连理工大学生命科学与技术学院,大连116024 [2]上海交通大学生命科学技术学院微生物代谢国家重点实验室,上海200240

出　　处：《应用与环境生物学报》2016年第2期201-205,共5页Chinese Journal of Applied and Environmental Biology

基　　金：国家自然科学基金项目(21376043;31461143029);国家高技术研究发展计划(863计划;2012AA021205;2012AA101805)项目资助~~

摘　　要：利用纤维素原料生产乙醇一直是国内外研究的热点,但纤维素预处理过程产生的弱酸、酚类和糠醛等抑制物对酿酒酵母细胞生长和乙醇发酵具有抑制作用,因此,提高酿酒酵母细胞的环境胁迫耐受性是提高纤维素乙醇发酵效率的重要手段之一.对芳香族氨基酸代谢途径中分支酸歧化酶基因ARO7的过表达对酿酒酵母在胁迫条件下细胞生长和乙醇发酵性能的影响进行研究.结果显示,过表达ARO7的重组菌株在含有5.0 g/L乙酸的平板中生长优于对照菌株;在含有5.0 g/L乙酸的发酵培养基中进行乙醇发酵,过表达ARO7的重组菌株的发酵效率高于对照菌株,在菊芋秸秆水解液中ARO7过表达重组酵母菌株乙醇得率由对照的0.44 g/g提高到0.47 g/g葡萄糖,乙醇生产强度提高了22.38%.以上表明,ARO7的过表达可提高酿酒酵母在抑制物存在条件下纤维素乙醇的发酵效率.Fuel ethanol production using lignocellulosic materials has attracted widespread attention. However, inhibitory compounds（e.g. weak acid, phenol and furfural） released from the pretreatment process exert inhibition on yeast cell growth and ethanol fermentation. Therefore, improvement of inhibitors tolerance of Saccharomyces cerevisiae benefits efficient cellulosic ethanol production. In this work, chorismate mutase encoding gene ARO7 which participates in aromatic amino acid biosynthesis was overexpressed in S. cerevisiae, the cell growth and ethanol production of the recombinant strain in the presence of inhibitory compounds were evaluated. It was found that the ARO7 overexpressing strain grew better than the control strain in the presence of 5.0 g/L acetic acid. Similar result was found when ethanol fermentation was performed with 5.0 g/L acetic acid addition. In addition, ethanol yield of the ARO7 overexpressing strain was improved from 0.44 g/g to 0.47 g/g glucose, and the ethanol productivity increased 22.38% when compared with the control strain using Jerusalem artichoke stalks hydrolysate. This work demonstrated that overexpression of ARO7 would be a feasible strategy to increase cellulosic ethanol production efficiency in the presence of inhibitors.

关 键 词：纤维素乙醇 菊芋秸秆 酿酒酵母 ARO7 乙酸 酵母菌环境胁迫耐受性 

分 类 号：TQ926[轻工技术与工程—发酵工程] TQ223.122