Optimizing CRISPR/Cas9 for high-expression genome loci in industrial yeast strains

Abstract

[Excerpt] The yeast Saccharomyces cerevisiae is one of the key cell factories for the production of bio-based chemicals, from fuels and bulk chemicals to active pharmaceuticals. Generally recognized as safe (GRAS) by the U. S. Food and Drug Administration and with a broad array of tools available at the molecular level, S. cerevisiae has been successfully manipulated for a wide range of applications. For large-scale fermentations, particularly in biorefineries, yeast cells must perform under harsh conditions, such as fluctuating pH and temperature, high osmotic pressure and presence of inhibitors derived from biomass hydrolysis. In this context, robust and stress-tolerant yeast chassis are required to attain high titers and product yields [1]. Industrial environments have been identified as a bioresource of yeast strains with higher robustness and fermentation performance and distinct strains have been isolated. [...]