Saccharomyces cerevisiae FLO1Gene Demonstrates Genetic Linkage to Increased Fermentation Rate at Low Temperatures

Abstract

Low fermentation temperatures are of importance to food and beverage industries working with Saccharomyces cerevisiae. Therefore, the identification of genes demonstrating a positive impact on fermentation kinetics is of significant interest. A set of 121 mapped F1 progeny, derived from a cross between haploid strains BY4716 (a derivative of the laboratory yeast S288C) and wine yeast RM11-1a, were fermented in New Zealand Sauvignon Blanc grape juice at 12.5°. Analyses of five key fermentation kinetic parameters among the F1 progeny identified a quantitative trait locus (QTL) on chromosome I with a significant degree of linkage to maximal fermentation rate (Vmax) at low temperature. Independent deletions of two candidate genes within the region, FLO1 and SWH1, were constructed in the parental strains (with S288C representing BY4716). Fermentation of wild-type and deletion strains at 12.5 and 25° confirmed that the genetic linkage to Vmax corresponds to the S288C version of the FLO1 allele, as the absence of this allele reduced Vmax by ∼50% at 12.5°, but not at 25°. Reciprocal hemizygosity analysis (RHA) between S288C and RM11-1a FLO1 alleles did not confirm the prediction that the S288C version of FLO1 was promoting more rapid fermentation in the opposing strain background, suggesting that the positive effect on Vmax derived from S288C FLO1 may only provide an advantage in haploids, or is dependent on strain-specific cis or trans effects. This research adds to the growing body of evidence demonstrating the role of FLO1 in providing stress tolerance to S. cerevisiae during fermentation.

Experimental evolution reveals favored adaptive routes to cell aggregation in yeast

“…The genomic context of the laboratory strain could have contributed to this finding; by evolving a strain with a nonsense mutation in flocculation transcription factor Flo8, we were functionally screening for bypass suppressors. A different genetic background might be more likely to reveal different favored adaptations for both flocculation and multicellular phenotypes, and recent work has demonstrated the important role of background in FLO1 performance during fermentation (Deed et al 2017). Despite the constraint provided by strain background, our findings are in keeping with other work in eukaryotes demonstrating favored adaptive responses, not just in the clear relationships between nutrient limitation and the amplification of nutrient transporters (Brown, Todd, and Rosenzweig 1998;Gresham et al 2008), but also in response to stress treatments.…”

A new analytical method to measure S‐methyl‐l‐methionine in grape juice reveals the influence of yeast on dimethyl sulfide production during fermentation

“…Eight milliliter micro-vinifications were performed in 13 mL ventilation-cap polypropylene tubes, with orbital shaking at 100 rpm. 31,32 Tube lids were perforated with a 0.5 mm 2 pinhole to allow for CO 2 release. The musts were inoculated using 1 × 10 6 mL −1 cells from overnight cultures as above and un-inoculated control samples were included to control for DMS formed chemically and independent of yeast.…”

“…blanc juice and wine were only 2.57% and 2.67%. The recoveries obtained with this method were also evaluated with the same Sauvignon blanc juice and wine at three different concentrations (31,310, 779 μg L −1 ) in duplicate. Recoveries in juice ranged from 101% to 106%, and the wine recoveries varied between 99% and 101%.…”

The CGI121 gene from Saccharomyces cerevisiae demonstrates genetic linkage to increased lag time under enological conditions

“…VII and one on Chr. XIII, that were signi cantly linked to fermentative lag [22]. Linkage analysis was performed on a set of 119/121 completely mapped (> 99% of the genome) F 1 progeny from a cross between haploid strains BY4716 and RM11-1a constructed by Brem et al [23].…”

“…This previous identi cation of chromosomal regions linked to lag phase duration provides an excellent opportunity to investigate the causative genes using a controlled and reproducible fermentation medium, such as synthetic grape medium (SGM). Since single reciprocal hemizygosity analysis (RHA) was not feasible for 44 different genes, we rst aimed to test the lag duration of BY4743 single deletants of each candidate ORF identi ed in Deed et al [22]. Those demonstrating variation in lag time compared to the BY4743 reference strain would be deleted in haploids RM11-1a and S288C, followed by the construction of RHA hybrids.…”