Yeasts: From the Laboratory to Bioprocesses

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.