Identification of target genes to control acetate yield during aerobic fermentation with Saccharomyces cerevisiae. Issue 1 (December 2016)

• Record Type: Journal Article
• Authors: Curiel, José; Salvadó, Zoel; Tronchoni, Jordi; Morales, Pilar; Rodrigues, Alda; Quirós, Manuel; Gonzalez, Ramón
• Is Part Of: Microbial cell factories. Volume 15:Issue 1(2016)
• Page Start: 1
• Page End: 11
• Publication Date: 2016-12
• Subjects: Aerobic fermentation -- Crabtree effect -- Volatile acidity -- Alcohol level reduction -- Carbon catabolite derepression -- Wine; Microbial biotechnology -- Periodicals; Recombinant proteins -- Synthesis -- Periodicals; 660.62
• DOI: 10.1186/s12934-016-0555-y
• Languages: English
• ISSNs: 1475-2859

Abstract

Abstract Background Aerobic fermentation of grape must, leading to respiro-fermentative metabolism of sugars, has been proposed as way of reducing alcohol content in wines. Two factors limit the usefulness ofSaccharomyces cerevisiae for this application, the Crabtree effect, and excess volatile acidity under aerobic conditions. This work aimed to explore the impact on ethanol acetate production of differentS. cerevisiae strains deleted for genes previously related with the Crabtree phenotype. Results Recombinant strains were constructed on a wine industrial genetic background, FX10. All yeast strains, including FX10, showed respiro-fermentative metabolism in natural grape must under aerobic conditions, as well as a concomitant reduction in ethanol yield. This indicates that the Crabtree effect is not a major constrain for reaching relevant respiration levels in grape must. Indeed, only minor differences in ethanol yield were observed between the original and some of the recombinant strains. In contrast, some yeast strains showed a relevant reduction of acetic acid production. This was identified as a positive feature for the feasibility of alcohol level reduction by respiration. Reduced acetic acid production was confirmed by a thorough analysis of these and some additional deletion strains (involving genesHXK2, PYK1, REG1, PDE2 andPDC1 ). Some recombinant yeasts showed altered production of glycerol and pyruvate derived metabolites. Conclusions REG1 andPDC1 deletion strains showed a strong reduction of acetic acid yield in aerobic fermentations. SinceREG1 defective strains may be obtained by non-GMO approaches, these gene modifications show good promise to help reducing ethanol content in wines.