Department of Chemical Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Nam-gu, Pohang 790-784, Korea.
Nat Commun. 2013;4:1413. doi: 10.1038/ncomms2404.
An extension of directed evolution strategies to genome-wide variations increases the chance of obtaining metabolite-overproducing microbes. However, a general high-throughput screening platform for selecting improved strains remains out of reach. Here, to expedite the evolution of metabolite-producing microbes, we utilize synthetic RNA devices comprising a riboswitch and a selection module that specifically sense inconspicuous metabolites. Using L-lysine-producing Escherichia coli as a model system, we demonstrated that this RNA device could enrich pathway-optimized strains to up to 75% of the total population after four rounds of enrichment cycles. Furthermore, the potential applicability of this device was examined by successfully extending its application to the case of L-tryptophan. When used in conjunction with combinatorial mutagenesis for metabolite overproduction, our synthetic RNA device should facilitate strain improvement.
定向进化策略的扩展到全基因组变异增加了获得代谢物高产微生物的机会。然而，一种通用的高通量筛选平台来选择改良菌株仍然遥不可及。在这里，为了加速代谢产物产生微生物的进化，我们利用包含一个核糖开关和一个选择模块的合成 RNA 器件，该器件专门感应不明显的代谢物。使用产 L-赖氨酸的大肠杆菌作为模型系统，我们证明这种 RNA 器件可以在四轮富集循环后将途径优化的菌株富集到总群体的 75%。此外，还通过成功地将该器件的应用扩展到 L-色氨酸的情况来检验该器件的潜在适用性。当与代谢物过量生产的组合诱变结合使用时，我们的合成 RNA 器件应该有助于菌株的改进。
