Molecular characterization and oenological properties of wine yeasts isolated during spontaneous fermentation of six varieties of grape must

Abstract

Fermentation by naturally occurring yeasts may produce wines of complex oenological properties that are unique to a specific region. The present work analyses the population dynamics of the yeasts during spontaneous fermentation of six varieties of grape must from the “Valle del Andarax” area (Spain). In this study we identified members of the genera Candida, Hanseniaspora, Issatchenkia, Metschnikowia, Pichia and Saccharomyces by PCR-RFLP of the ITS region. The capability of these yeasts to ferment grape must of the Macabeo variety was studied, and the volatile profile of the wine from each microvinification has been determined. Of all the yeasts isolated Candida stellata and Saccharomyces cerevisiae were able to consume virtually all the initial glucose, producing ethanol contents typical of table wines. The best profile of higher alcohols was given by Saccharomyces cerevisiae followed by Hanseniaspora uvarum, Issatchenkia orientalis and Candida stellata. Metschnikowia pulcherrima and Pichia fermentans showed the highest production of ethyl caprilate and 2-phenyl ethanol, compounds associated with pleasant aromas.