Optogenetic Amplification Circuits for Light-Induced Metabolic Control.

TitleOptogenetic Amplification Circuits for Light-Induced Metabolic Control.
Publication TypeJournal Article
Year of Publication2021
AuthorsZhao, EM, Lalwani, MA, Chen, J-M, Orillac, P, Toettcher, JE, Avalos, JL
JournalACS Synth Biol
Date Published2021 May 21
KeywordsBioreactors, Butanols, DNA-Binding Proteins, Enzyme Activation, Fermentation, Flavanones, Gene Expression, Gene Expression Regulation, Lactic Acid, Light, Metabolic Engineering, Metabolic Networks and Pathways, Microorganisms, Genetically-Modified, Optogenetics, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins, Signal Transduction, Transcription Factors, Transcription, Genetic

<p>Dynamic control of microbial metabolism is an effective strategy to improve chemical production in fermentations. While dynamic control is most often implemented using chemical inducers, optogenetics offers an attractive alternative due to the high tunability and reversibility afforded by light. However, a major concern of applying optogenetics in metabolic engineering is the risk of insufficient light penetration at high cell densities, especially in large bioreactors. Here, we present a new series of optogenetic circuits we call OptoAMP, which amplify the transcriptional response to blue light by as much as 23-fold compared to the basal circuit (OptoEXP). These circuits show as much as a 41-fold induction between dark and light conditions, efficient activation at light duty cycles as low as ∼1%, and strong homogeneous light-induction in bioreactors of at least 5 L, with limited illumination at cell densities above 40 OD. We demonstrate the ability of OptoAMP circuits to control engineered metabolic pathways in novel three-phase fermentations using different light schedules to control enzyme expression and improve production of lactic acid, isobutanol, and naringenin. These circuits expand the applicability of optogenetics to metabolic engineering.</p>

Alternate JournalACS Synth Biol
PubMed ID33835777
PubMed Central IDPMC8721662
Grant ListDP2 EB024247 / EB / NIBIB NIH HHS / United States