Evidence for differences between B. bruxellensis strains originating from an enological environment

Vincent Renouf^1,2, Cécile Miot-Sertier², Marie-Claire Perello², Gilles de Revel², Aline Lonvaud-Funel²

¹Laffort, Bordeaux, France; ²UMR Œnologie, INRA-Université Bordeaux, France

Abstract: The aim of this paper is to study and compare the physiological diversity of different strains of a wine spoilage yeast species: Brettanomyces bruxellensis. The minimum inhibitory concentrations of several drugs on different B. bruxellensis strains were scored on solid nutrient media. This revealed variations in resistance among the B. bruxellensis strains. Their capacity to develop in different wine and must environments: pH, ethanol, and SO₂ concentrations, were evaluated by measuring the direct incubation survival rate. The results, compared with those obtained for other wine yeast species, confirmed the remarkable resistance of B. bruxellensis strains to various conditions which inhibit the growth of other species. Nevertheless some differences were observed among the B. bruxellensis strains, thus confirming their physiological diversity. A comparison of their volatile phenol production revealed intraspecific heterogeneity among B. bruxellensis strains. B. bruxellensis is one of the microbial species most resistant to environmental constraints in wine. It is the best adapted to growing in wine and spoiling it by volatile phenol production. However, different B. bruxellensis strains exhibit varying characteristics, particularly their capacity to produce volatile phenols. This implies that certain strains are more prejudicial than others. Further studies are required to determine the molecular causes of this intraspecific diversity.

Keywords: Brettanomyces bruxellensis, strain diversity, physiology, volatile phenols