Design and Characterization of Rapid Optogenetic Circuits for Dynamic Control in Yeast Metabolic Engineering. Author Evan Zhao, Makoto Lalwani, Robert Lovelett, Sergio García-Echauri, Shannon Hoffman, Christopher Gonzalez, Jared Toettcher, Ioannis Kevrekidis, José Avalos Publication Year 2020 Type Journal Article 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 . 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 promoter (P), which is stronger than any constitutive or inducible promoter commonly used in yeast. Combining OptoINVRT7 with P achieves strong and light-tunable levels of gene expression with as much as 132.9 ± 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 open the door to applying process control tools to engineered metabolisms to improve robustness and yields in microbial fermentations for chemical production. Keywords Promoter Regions, Genetic, Lactic Acid, Light, Saccharomyces cerevisiae, Optogenetics, Gene Expression Regulation, Fungal, Butanols, Plasmids, Metabolic Engineering, Galactokinase Journal ACS Synth Biol Volume 9 Issue 12 Pages 3254-3266 Date Published 2020 Dec 18 ISSN Number 2161-5063 DOI 10.1021/acssynbio.0c00305 Alternate Journal ACS Synth Biol PMID 33232598 PubMedGoogle ScholarBibTeXEndNote X3 XML