Biodiversity among Brettanomyces bruxellensis Strains Isolated from Different Wine Regions of Chile: Key Factors Revealed about Its Tolerance to Sulphite

Abstract

Brettanomyces bruxellensis is regarded as the main spoilage microorganism in the wine industry, owing to its production of off-flavours. It is difficult to eradicate owing to its high tolerance of adverse environmental conditions, such as low nutrient availability, low pH, and high levels of ethanol and SO2. In this study, the production of volatile phenols and the growth kinetics of isolates from various regions of Chile were evaluated under stressful conditions. Through randomly amplified polymorphic DNA (RAPD) analysis, 15 strains were identified. These were grown in the presence of p-coumaric acid, a natural antimicrobial and the main precursor of off-flavours, and molecular sulfur dioxide (mSO2), an antimicrobial synthetic used in the wine industry. When both compounds were used simultaneously, there were clear signs of an improvement in the fitness of most of the isolates, which showed an antagonistic interaction in which p-coumaric acid mitigates the effects of SO2. Fourteen strains were able to produce 4-vinylphenol, which showed signs of phenylacrylic acid decarboxylase activity, and most of them produced 4-ethylphenol as a result of active vinylphenol reductase. These results demonstrate for the first time the serious implications of using p-coumaric acid, not only for the production of off-flavours, but also for its protective action against the toxic effects of SO2.

Prediction of Genetic Groups within Brettanomyces bruxellensis through Cell Morphology Using a Deep Learning Tool

“…Another PCR-based technique was the Random Amplified Polymorphism DNA PCR (RAPD-PCR) method. This method was most widely used to study intraspecific diversity among B. bruxellensis species, even if it could sometimes be combined with other methods to improve discrimination [19,21,[31][32][33][34][35][36][37]. The first use of RAPD-PCR provided poor discrimination of wine isolates from reference strains [31], but the method was improved by combining the individual profiles of each primer to assign composite profiles to each strain, making it more discriminating [19].…”

Editorial for Special Issue “Yeast in Winemaking”

“…An example is given in this Special Issue with Brettanomyces, which is considered the nightmare of winemakers. G-Poblete et al [ 6 ] report that p-coumaric acid has a protective action against the toxic effects of SO 2 .…”