Ethanol production process driving changes on industrial strains

• Published in: FEMS yeast research Vol. 21; no. 1; pp. 1 - 10
• Main Authors: Nagamatsu, Sheila Tiemi, Coutouné, Natalia, José, Juliana, Fiamenghi, Mateus Bernabe, Pereira, Gonçalo Amarante Guimarães, Oliveira, Juliana Velasco de Castro, Carazzolle, Marcelo Falsarella
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01-02-2021
• Subjects: Acetaldehyde; Adaptation; Alcohol; Alcohol, Denatured; Biodiesel fuels; Biofuels; Ethanol; Fermentation; Genetic aspects; Genomes; Genomics; Homeostasis; Industrial applications; Industrial strains; Maltose; Phylogeny; Positive selection; Production data; Production processes; Sugarcane; Brazil; first-generation ethanol production; industrial strain; corn; comparative genomics; sugarcane; Saccharomyces cerevisiae
• DOI: 10.1093/femsyr/foaa071
• EISSN: 1567-1364
• ISSN: 1567-1364; 1567-1356

ABSTRACT
Ethanol production has key differences between the two largest producing countries of this biofuel, Brazil and the USA, such as feedstock source, sugar concentration and ethanol titers in industrial fermentation. Therefore, it is highly probable that these specificities have led to genome adaptation of the Saccharomyces cerevisiae strains employed in each process to tolerate different environments. In order to identify particular adaptations, in this work, we have compared the genomes of industrial yeast strains widely used to produce ethanol from sugarcane, corn and sweet sorghum, and also two laboratory strains as reference. The genes were predicted and then 4524 single-copy orthologous were selected to build the phylogenetic tree. We found that the geographic location and industrial process were shown as the main evolutionary drivers: for sugarcane fermentation, positive selection was identified for metal homeostasis and stress response genes, whereas genes involved in membrane modeling have been connected with corn fermentation. In addition, the corn specialized strain Ethanol Red showed an increased number of copies of MAL31, a gene encoding a maltose transporter. In summary, our work can help to guide new strain chassis selection for engineering strategies, to produce more robust strains for biofuel production and other industrial applications.
Understanding how the environment can drive changes in industrial yeasts is important for detecting genes that are under selection and may impact the adaptive process.