Efficient 3-Hydroxybutyrate Production by Quiescent Escherichia coli Microbial Cell Factories is Facilitated by Indole-Induced Proteomic and Metabolomic Changes.
Efficient 3-Hydroxybutyrate Production by Quiescent Escherichia coli Microbial Cell Factories is Facilitated by Indole-Induced Proteomic and Metabolomic Changes.
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DOI：
10.1002/biot.201700571
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发表时间：
2018-05
影响因子：
4.7
通讯作者：
Nicholas M. Thomson;Tomokazu Shirai;M. Chiapello;A. Kondo;K. J. Mukherjee;E. Sivaniah;K. Numata;D. Summers
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作者：
Nicholas M. Thomson;Tomokazu Shirai;M. Chiapello;A. Kondo;K. J. Mukherjee;E. Sivaniah;K. Numata;D. Summers
作者表明，静止（q细胞）大肠杆菌培养物可以在没有生长的情况下保持代谢活性长达24小时，导致模型代谢物3-羟基丁酸酯（3HB）的比生产力比对照组高4倍。q细胞可以通过使用质子离子载体吲哚来阻止hns突变株的细胞分裂而产生。这使得新陈代谢与细胞生长分离，并允许更有效地利用碳原料，因为较少的代谢努力被转移到剩余的生物质生产中。然而，细胞在静止状态下生产力增加的原因以前是未知的。在这项研究中，野生型和q细胞培养物之间的蛋白质组表达模式表明，q细胞过度表达应激反应蛋白，这使它们能够耐受吲哚添加引起的代谢失衡。代谢组学数据显示乙酰辅酶A和磷酸烯醇丙酮酸的积累是高价值化学品生产的良好起点。我们通过设计一个简单的途径来利用这些积累的代谢物，使乙酰辅酶a产生3HB，静止培养物产生的细胞生物量是缺乏吲哚的对照培养物的一半，但仍然能够产生39.4 g L-1的3HB，而对照组为18.6 g L-1。因此，Q-cells作为一种平台技术具有巨大的潜力，可以有效地生产各种商品和高价值化学品。
The authors show that quiescent (Q-Cell) Escherichia coli cultures can maintain metabolic activity in the absence of growth for up to 24 h, leading to four times greater specific productivity of a model metabolite, 3-hydroxybutyrate (3HB), than a control. Q-cells can be created by using the proton ionophore indole to halt cell division of an hns mutant strain. This uncouples metabolism from cell growth and allows for more efficient use of carbon feedstocks because less metabolic effort is diverted to surplus biomass production. However, the reason for the increased productivity of cells in the quiescent state was previously unknown. In this study, proteome expression patterns between wild-type and Q-cell cultures show that Q-cells overexpress stress response proteins, which prime them to tolerate the metabolic imbalances incurred through indole addition. Metabolomic data reveal the accumulation of acetyl-coenzyme A and phosphoenolpyruvate: excellent starting points for high-value chemical production. We demonstrate the exploitation of these accumulated metabolites by engineering a simple pathway for 3HB production from acetyl-coenzyme A. Quiescent cultures produced half the cell biomass of control cultures lacking indole, but were still able to produce 39.4 g L-1 of 3HB compared to 18.6 g L-1 in the control. Q-cells therefore have great potential as a platform technology for the efficient production of a wide range of commodity and high value chemicals.