中链烷烃生物合成新途径的构建与调控研究

项目名称： 中链烷烃生物合成新途径的构建与调控研究

项目编号： No.21376024

项目类型： 面上项目

立项/批准年度： 2014

项目学科： 化学工程及工业化学

项目作者： 刘珞

作者单位： 北京化工大学

项目金额： 40万元

中文摘要： 利用可再生资源生产生物能源是目前解决能源危机的重要办法。相比乙醇等生物燃料，烷烃有能量密度等优点，是最好的液体燃料。但已报道的烷烃生物合成途径产量低，产物不可设计，使用范围局限。本项目提出一种全新的代谢途径，以解决上述两个问题。已知的烷烃合成途径由酯酰ACP还原酶起始，主产物为十六烷醛，脱去羰基合成十五烷。酯酰ACP还原酶主要存在于细菌中，缺乏底物选择性。很多植物会积累特定链长的脂肪酸，例如月桂树积累月桂酸等中链脂肪酸，机理为特异性酯酰ACP硫酯酶造成的特定链长酯酰ACP的水解。以此为基础，大肠杆菌表达的月桂树硫酯酶会积累月桂酸及肉豆蔻酸。通过酯酰CoA连接酶，脂肪酸转化为酰基CoA，在酰基CoA还原酶的还原下，形成相应脂肪醛，被脱羰基酶脱去羰基为终产物十一、十三烷。构建该途径后，通过调控能量平衡，为实现产各种烷烃燃料的细胞工厂提供初步工作基础和理论依据

中文关键词： 烷烃生物合成；航空燃料；中链烷烃；三磷酸腺苷；表面增强拉曼散射

英文摘要： Producing bioenergy from renewable resource is an important approach to solve the energy problem. Compare to ethanol and biodiesel, alkanes show high energy density and low freezing point, are the best liquid fuels. The productivity of the reported alkane biosynthesis pathway was low, and the products could not be controlled. The utilization of this pathway is very limited. In this proposal, we will design a novel metabolic pathway, to overcome above-mentioned drawbacks. The current alkane biosynthesis pathway is initiated by acyl-ACP reductase, forming main product palmitic aldehyde. After decarbonylation, the final product pentadecane is produced. Acyl-ACP reductases distribute mainly in bacteria with low diversity. And the selectivity is major towards long-chain fatty acyl-ACP. In contrary, fatty acyl-ACP thioesterases from plants have large diversity and are able to distinguish different chain-length of fatty acyl-ACP from short chain to long chain. For each thioesterase the specificity can be very high. For example, the thioesterase from Umbellularia californica produces lauric acid and myristic acid by expression in E. coli. The fatty acids are than ligated to CoA by acyl-CoA ligase. After reduction by Fatty acyl-CoA reductase catalyzes the fatty acyl-CoA to the fatty aldehyde. Final, undecane and tridecan

英文关键词： Alkane biosynthesis；Jet fuel；Medium-chain alkane；ATP；surface-enhanced Raman scattering