@article{178401,
  author = {Evan M. Zhao and Makoto A. Lalwani and Robert J. Lovelett and Sergio A. Garc{\'\i}a-Echauri and Shannon M. Hoffman and Christopher L. Gonzalez and Jared E. Toettcher and IoannisG. Kevrekidis and Jos{\'e} L. Avalos},
  title = {Design and Characterization of Rapid Optogenetic Circuits for Dynamic Control in Yeast Metabolic Engineering},
  abstract = { The use of optogenetics in metabolic engineering for light-controlled microbial chemical production raises the prospect of utilizing control and optimization techniques routinely deployed in traditional chemical manufacturing. However, such mechanisms require well-characterized, customizable tools that respond fast enough to be used as real-time inputs during fermentations. Here, we present OptoINVRT7, a new rapid optogenetic inverter circuit to control gene expression in~<i>Saccharomyces cerevisiae</i>. The circuit induces gene expression in only 0.6 h after switching cells from light to darkness, which is at least 6 times faster than previous OptoINVRT optogenetic circuits used for chemical production. In addition, we introduce an engineered inducible~<i>GAL1</i>~promoter (P<sub>GAL1-S</sub>), which is stronger than any constitutive or inducible promoter commonly used in yeast. Combining OptoINVRT7 with P<sub>GAL1-S</sub>~achieves strong and light-tunable levels of gene expression with as much as 132.9 {\textpm} 22.6-fold induction in darkness. The high performance of this new optogenetic circuit in controlling metabolic enzymes boosts production of lactic acid and isobutanol by more than 50\% and 15\%, respectively. The strength and controllability of OptoINVRT7 and P<sub>GAL1-S</sub>~open the door to applying process control tools to engineered metabolisms to improve robustness and yields in microbial fermentations for chemical production. },
  year = {2020},
  journal = {ACS Synthetic Biology},
  volume = {9},
  pages = {3254{\textendash}3266},
  url = {https://pubs.acs.org/doi/10.1021/acssynbio.0c00305},
  language = {eng},
}