The optimization of engineered metabolic pathways requires careful control over the levels and timing of metabolic enzyme expression. Optogenetic tools are ideal for achieving such precise control, as light can be applied and removed instantly without complex media changes. Here we show that light-controlled transcription can be used to enhance the biosynthesis of valuable products in engineered Saccharomyces cerevisiae. We introduce new optogenetic circuits to shift cells from a light-induced growth phase to a darkness-induced production phase, which allows us to control fermentation with only light. Furthermore, optogenetic control of engineered pathways enables a new mode of bioreactor operation using periodic light pulses to tune enzyme expression during the production phase of fermentation to increase yields. Using these advances, we control the mitochondrial isobutanol pathway to produce up to 8.49 ± 0.31 g l−1 of isobutanol and 2.38 ± 0.06 g l−1 of 2-methyl-1-butanol micro-aerobically from glucose. These results make a compelling case for the application of optogenetics to metabolic engineering for the production of valuable products.

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微生物化学生产工程细胞代谢的光遗传学调控

工程代谢途径的优化需要仔细控制代谢酶表达的水平和时间。光遗传学工具是实现这种精确控制的理想选择，因为无需复杂的介质更改即可立即施加和移除光。在这里，我们表明光控转录可用于增强工程酿酒酵母中有价值产品的生物合成。我们引入了新的光遗传学电路，将细胞从光诱导的生长阶段转变为黑暗诱导的生产阶段，这使我们能够仅用光来控制发酵。此外，工程化途径的光遗传学控制实现了一种新的生物反应器操作模式，使用周期性光脉冲在发酵的生产阶段调整酶表达以提高产量。利用这些进步，我们控制线粒体异丁醇途径以从葡萄糖微有氧产生高达 8.49 ± 0.31 g l-1 的异丁醇和 2.38 ± 0.06 g l-1 的 2-甲基-1-丁醇。这些结果为将光遗传学应用于代谢工程以生产有价值的产品提供了令​​人信服的案例。