Identification and characterization of non-saccharomyces spoilage yeasts isolated from Brazilian wines

Abstract

The industry of fine wines and also locally consumed table wines is emerging in Brazil with an increasing volume and economic impact. Enologists in this region currently lack information about the prevalence and characteristics of spoilage yeasts, which may contaminate and potentially undervalue Brazilian wines. Herein, we analyzed 50 local red wines including 27 fine wines (V. vinifera) and 23 table wines (V. labrusca). Presumptive spoilage yeasts were isolated on differential medium, and classified by RFLP-PCR and sequencing of the ITS1-5.8S-ITS2 and D1/D2 26S rDNA loci. The prevalence of spoilage yeasts in fine wines (11%) was comparable to that reported in European and US wines, and significantly lower than that observed for local table wines (70%). The majority of isolates belonged to Brettanomyces bruxelliensis, followed by Pichia guillermondii, and more rarely Candida wickerhamii and Trigonopsis cantarelli. The Brettanomyces isolates varied greatly in off-flavor production, displayed ethanol tolerance (>10% by volume), tolerated sulfite (≥0.68mg/l mSO2), and 39% of them grew on ethanol as sole carbon source. We discuss the causes and consequences of spoilage yeasts in relation to the Brazilian wine industry.