CRISPR/Cas9 in Saccharomyces cerevisiae: development of a multiple genomic edition approach in industrial strains

Abstract

Saccharomyces cerevisiae yeasts are largely employed on the development of strains applied on industrial production of chemicals, such as renewable fuels. In this context, yeasts adapted to industrial conditions - industrial yeasts - are considered adequate backgrounds due to their tolerance to many different kinds of stresses inherents to different processes. Even though S. cerevisiae yeasts are known as organisms easily susceptible to genetic manipulation, wild strains are usually diploid or polyploid and, for that reason, require the development or adaptation of efficient genetic manipulation tools. In this context the CRISPR/Cas9 system for genomic edition figures as the best manipulation alternative due to its simplicity, efficiency and non-necessity of previous handling - domestication - and co-integration of selection markers. This project proposes the development of a genomic edition approach on industrial yeast strains based on the CRISPR/Cas9 method. By that, the main objective is the acceleration of the development of more productive strains, linked with industrial processes that predict the use of renewable feedstock. As concept proof manipulations on a PE-2 (JAY270) industrial yeast are going to be performed, making it possible to evaluate the individual and synergistic effect of the 3 alleles related to the conference of thermotolerance. Comprehending the genetic basis linked with thermotolerance will allow the optimization of the yeast performance in high temperatures, leading to greater productive gains due to the significant decrease of operational costs related to fermenting time and temperature control. (AU)