Molecular Diagnosis of Brettanomyces bruxellensis’ Sulfur Dioxide Sensitivity Through Genotype Specific Method

Abstract

The yeast species Brettanomyces bruxellensis is associated with important economic losses due to red wine spoilage. The most common method to prevent and/or control B. bruxellensis spoilage in winemaking is the addition of sulfur dioxide into must and wine. However, recently, it was reported that some B. bruxellensis strains could be tolerant to commonly used doses of SO2. In this work, B. bruxellensis response to SO2 was assessed in order to explore the relationship between SO2 tolerance and genotype. We selected 145 isolates representative of the genetic diversity of the species, and from different fermentation niches (roughly 70% from grape wine fermentation environment, and 30% from beer, ethanol, tequila, kombucha, etc.). These isolates were grown in media harboring increasing sulfite concentrations, from 0 to 0.6 mg.L-1 of molecular SO2. Three behaviors were defined: sensitive strains showed longer lag phase and slower growth rate and/or lower maximum population size in presence of increasing concentrations of SO2. Tolerant strains displayed increased lag phase, but maximal growth rate and maximal population size remained unchanged. Finally, resistant strains showed no growth variation whatever the SO2 concentrations. 36% (52/145) of B. bruxellensis isolates were resistant or tolerant to sulfite, and up to 43% (46/107) when considering only wine isolates. Moreover, most of the resistant/tolerant strains belonged to two specific genetic groups, allowing the use of microsatellite genotyping to predict the risk of sulfur dioxide resistance/tolerance with high reliability (>90%). Such molecular diagnosis could help the winemakers to adjust antimicrobial techniques and efficient spoilage prevention with minimal intervention.

Brettanomyces bruxellensis SSU1Haplotypes Confer Different Levels of Sulfite Tolerance When Expressed in aSaccharomyces cerevisiae SSU1Null Mutant

“…This finding was extended recently through microsatellite analysis of more than 1,400 B. bruxellensis isolates, which revealed distinct genetic clusters defined by ploidy and substrate of isolation (14). One of these, the AWRI1499-like triploid wine group, was composed of isolates highly tolerant to SO 2 , while isolates from substrates other than wine were all sensitive, suggesting a link between SO 2 exposure in wine and tolerance to this preservative (14,15).…”

Vitis species, vintage, and alcoholic fermentation do not drive population structure in Starmerella bacillaris (synonym Candida zemplinina) species

“…cerevisiae , microsatellite analysis revealed a strong association between human processes and genetic structure (Legras, Ruh, Merdinoglu, & Karst, ), a feature indicative of domestication that was subsequently confirmed by genomic analyses (Liti et al, ; Peter et al, ). More recently, associations between genetic structure and human processes (e.g., winemaking) were evidenced in yeasts Torulaspora delbrueckii , Lachancea thermotolerans , and Brettanomyces bruxellensis (Albertin et al, ; Avramova, Vallet‐Courbin, Maupeu, Masneuf‐Pomarède, & Albertin, ; Hranilovic, Bely, Masneuf‐Pomarede, Jiranek, & Albertin, ). For all these species, at least two independent events of domestication were identified, indicating that anthropization drastically shapes the genetic diversity of these wine yeasts.…”

Modification of Chitosan for the Generation of Functional Derivatives

“…Practically, CS is rather widely used for its antimicrobial properties in wine and more precisely to control the spoilage yeast Brettanomyces bruxellensis [76,77]. In a context where sulphur addition is more and more limited and the emergence of sulphur resistant yeast populations has been demonstrated [78], the use of CS as a curative and preventive agent is increasing among winemakers. Moreover, the 10 g/hL maximal and efficient dose to reduce these spoilage yeast populations is compatible from both a practical and economical point of view.…”