The unbalanced distribution of carbon flux in microbial cell factories can lead to inefficient production and poor cell growth. Uncoupling cell growth and chemical synthesis can therefore improve microbial cell factory efficiency. Such uncoupling, which requires precise manipulation of carbon fluxes, can be achieved by up-regulating or down-regulating the expression of enzymes of various pathways. In this study, a dynamic turn-off switch (dTFS) and a dynamic turn-on switch (dTNS) were constructed using growth phase-dependent promoters and degrons. By combining the dTFS and dTNS, a bifunctional molecular switch that could orthogonally regulate two target proteins was introduced. This bifunctional molecular switch was used to uncouple cell growth from shikimic acid and D-glucaric acid synthesis, resulting in the production of 14.33 g/L shikimic acid and the highest reported productivity of D-glucaric acid (0.0325 g/L/h) in Escherichia coli MG1655. This proved that the bifunctional molecular switch could rewire carbon fluxes by controlling target protein abundance.

微生物细胞工厂中碳通量的不平衡分布会导致生产效率低下和细胞生长不良。因此，解耦细胞生长和化学合成可以提高微生物细胞工厂的效率。这种需要精确控制碳通量的解偶联可以通过上调或下调各种途径酶的表达来实现。在这项研究中，动态关闭开关 (dTFS) 和动态开启开关 (dTNS) 是使用生长阶段相关的启动子和 degron 构建的。通过结合 dTFS 和 dTNS，引入了一种可以正交调节两种靶蛋白的双功能分子开关。这种双功能分子开关用于将细胞生长与莽草酸和 D-葡糖二酸的合成分离，从而产生 14。大肠杆菌MG1655。这证明双功能分子开关可以通过控制目标蛋白质丰度来重新连接碳通量。