Genome engineering of E. coli for improved styrene production
Genome engineering of E. coli for improved styrene production
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DOI：
10.1016/j.ymben.2019.09.007
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发表时间：
2020-01-01
影响因子：
8.4
通讯作者：
Gill, Ryan T.
中科院分区：
文献类型：
--
作者：
Liang, Liya;Liu, Rongming;Gill, Ryan T.
微生物生产外源有机化合物具有挑战性，因为生物合成途径通常很复杂并且产生对宿主有毒的代谢物。生物苯乙烯就是这个问题的一个例子，如果解决这个问题，可能会导致塑料行业这一重要组成部分的供应更加可持续。在这项研究中，我们改造了大肠杆菌来生产苯乙烯。我们首先筛选大肠杆菌菌株中不同途径的表达水平，系统地优化了生产能力。然后，我们进一步设计并构建了一个针对 54 个基因（85,420 个突变）的转录调控子文库，并测试了该文库的苯乙烯抗性和产量的增加。与亲本菌株相比，一系列耐受突变体不仅表现出改善的苯乙烯耐受性，而且产生更高的苯乙烯浓度。产量最好的突变体 ST05 LexA_E45I 与亲本菌株相比，苯乙烯产量增加了 3.45 倍。通过气提将产生的苯乙烯提取到十二烷中，并用于聚苯乙烯的直接自由基合成。
Microbial production of exogenous organic compounds is challenging as biosynthetic pathways are often complex and produce metabolites that are toxic to the hosts. Biogenic styrene is an example of this problem, which if addressed could result in a more sustainable supply of this important component of the plastics industry. In this study, we engineered Escherichia coli for the production of styrene. We systematically optimized the production capability by first screening different pathway expression levels in E. coli strains. We then further designed and constructed a transcription regulator library targeting 54 genes with 85,420 mutations, and tested this library for increased styrene resistance and production. A series of tolerant mutants not only exhibited improved styrene tolerance but also produced higher styrene concentrations compared to the parent strain. The best producing mutant, ST05 LexA_E45I, produced a 3.45-fold increase in styrene compared to the parent strain. The produced styrene was extracted via gas stripping into dodecane and used in a direct free radical synthesis of polystyrene.