Xiao Shiyuan, Xu Jingliang, Chen Xiaoyan, Li Xiekun, Zhang Yu, Yuan Zhenhong
Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou, China.
University of Chinese Academy of Sciences, Beijing, China.
Mol Biotechnol. 2016 May;58(5):311-8. doi: 10.1007/s12033-016-9929-y.
Biofuel offers a promising solution to the adverse environmental problems and depletion in reserves of fossil fuels. Higher alcohols including 3-methyl-1-butanol were paid much more attention as fuel substitute in recent years, due to its similar properties to gasoline. In the present work, 3-methyl-1-butanol production in engineered Corynebacterium glutamicum was studied. α-Ketoisovalerate decarboxylase gene (kivd) from Lactococcus lactis combined with alcohol dehydrogenase gene (adh2, adhA, and adh3) from three organisms were overexpressed in C. glutamicum. Enzymatic assay and alcohol production results showed that adh3 from Zymomonas mobilis was the optimum candidate for 3-methyl-1-butanol production in C. glutamicum. The recombinant with kivd and adh3 could produce 0.182 g/L of 3-methyl-1-butanol and 0.144 g/L of isobutanol after 12 h of incubation. Further inactivation of the E1 subunit of pyruvate dehydrogenase complex gene (aceE) and lactic dehydrogenase gene (ldh) in the above C. glutamicum strain would improve the 3-Methyl-1-butanol titer to 0.497 g/L after 12 h of incubation.
生物燃料为解决不利的环境问题和化石燃料储备枯竭提供了一个有前景的解决方案。包括3-甲基-1-丁醇在内的高级醇近年来作为燃料替代品受到了更多关注，因为其性质与汽油相似。在本研究中，对工程改造的谷氨酸棒杆菌生产3-甲基-1-丁醇进行了研究。来自乳酸乳球菌的α-酮异戊酸脱羧酶基因（kivd）与来自三种生物的乙醇脱氢酶基因（adh2、adhA和adh3）在谷氨酸棒杆菌中过表达。酶活性测定和酒精生产结果表明，运动发酵单胞菌的adh3是谷氨酸棒杆菌生产3-甲基-1-丁醇的最佳候选基因。携带kivd和adh3的重组菌在培养12小时后可产生0.182 g/L的3-甲基-1-丁醇和0.144 g/L的异丁醇。在上述谷氨酸棒杆菌菌株中进一步敲除丙酮酸脱氢酶复合体基因（aceE）的E1亚基和乳酸脱氢酶基因（ldh），培养12小时后3-甲基-1-丁醇的产量可提高到0.497 g/L。
