Spoilage traits and control of Brettanomyces bruxellensis: advances and implications for winemaking

Abstract

Background: Brettanomyces bruxellensis (B. bruxellensis) is a persistent spoilage organism of beverage fermentations, capable of producing volatile phenols that compromise product aroma and quality, particularly in wine. The yeast is highly adapted to the winery environment, withstanding acidity, ethanol, and nutrient limitations. Its various traits exacerbate its detection and elimination. Current chemical controls have limitations, thereby increasing the call for biological alternatives. Scope and approach: We review available literature to define the scope of the B. bruxellensis problem, its impact on beverages and the traits aiding its survival and recalcitrance. The basis of these, namely the viable but non-culturable (VBNC) state, biofilm formation, nutritional versatility and high genetic/phenotypic diversity is delineated. We provide a comprehensive summary of reported inhibitors of B. bruxellensis, their mode of action, advantages and disadvantages, performance in laboratory and/or industrial contexts, and commercial availability. Included are strategies based on sulfur dioxide (SO2), chitosan, or dimethyl dicarbonate, and those based on killer toxins, antimicrobial peptides and iron chelators. Key findings and conclusions: Currently, the most effective and common control for B. bruxellensis is the application of SO2. But increasingly tolerant strains are appearing and consumer preferences or allergies to SO2 highlight the critical need for better control agents. Several biological solutions, particularly those based on non-Saccharomyces yeasts, show promise but further research is needed. Importantly, future progress in controlling B. bruxellensis will depend on multi-strain efficacy testing, advanced detection methods to identify VBNC and biofilm associated cells, and the integration of complementary agents tailored to the wine or relevant substrate