Yeasts are important industrial platforms for the efficient production of
foods, beverages, commodity chemicals, and biofuels. Although these yeasts usually
have beneficial native phenotypes, it is often desirable to engineer these cell factories
to increase yield, titer, and production rates, or even promote the production of new
molecules. In the present chapter, we describe several classical genetic approaches to
improve industrial yeast strains (mating, cell and protoplast fusion techniques,
mutagenesis, genome shuffling, adaptive laboratory evolution, etc.), as well as methods
to identify the genetic basis of phenotypic traits, including phenotypes controlled by
quantitative trait loci (QTL), through bulk segregant analysis (BSA) and DNA
sequencing. We then review modern technologies for industrial yeast strain
improvement (genomic engineering through homologous recombination, CRISPRCas9,
synthetic chromosomes, synthetic genomes and SCRaMbLE) both in
conventional (mostly Saccharomyces strains) as well as non-conventional yeasts.
Finally, we give several current examples (and ideas for the future) of yeast strains
genetically modified in the laboratory to produce a range of commercial products and
biofuels through industrial bioprocesses.
Keywords: CRISPR-Cas9, Genetic engineering, Genomic engineering, Homologous recombination, SCRaMbLE, Synthetic chromosomes, Yeast breeding.