大肠杆菌异源生产丁醇途径组装及启动子优化

Butanol pathway construction and promoter optimization in Escherichia coli

摘要:

启动子优化是合成生物学研究的重要工具，可以通过不同强度的启动子调控基因转录水平以优化生物途径。丁醇是一种多用途的基础化工原料，目前有很多代谢工程手段应用在大肠杆菌的丁醇异源表达中，但是并没有进行启动子的精细调控。文中以大肠杆菌为宿主构建异源丁醇合成途径，通过DNA assembler的方法一步组装不同强度启动子组合的丁醇合成途径以优化丁醇合成。以强启动子Alper PLTetO1或弱启动子Alper BB转录硫解酶，以强启动子Braatsch 20或弱启动子Braatsch 10转录丁醇合成操纵子，共构建成4种不同质粒。结果表明以Alper PLTetO1转录硫解酶，Braatsch 10转录丁醇合成操纵子的组合获得最高的丁醇产量28 mg/L，与其他组合相比丁醇产量提高了3~5倍。

Abstract:

Promoter optimization is a useful tool in synthetic biology. Fusing promoters of various strengths to genes is a good method to get the best gene overexpression level. Butanol can be used as an intermediate in chemical synthesis and as a solvent for a wide variety of chemical and textile industry applications. At present, multiple metabolic engineering strategies have been attempted for butanol production in non-native host Escherichia coli. But there were little work on promoter optimization. We fused thlA (thiolase) with strong promoter Alper PLTetO1 or weak promoter Alper BB, operon with strong promoter Braatsch 20 or weak promoter Braatsch 10 by fast assemble method DNA assembler in Escherichia coli. The experimental results showed thlA with strong promoter Alper PLTetO1, operon with weak promoter Braatsch 10 got best butanol concentration 28mg/L, which increased at least 3~5 fold compared with other combination.