Wine Yeast Inhibition by Sulfur Dioxide: A Comparison of Culture-Dependent and Independent Methods

摘要

Culture-independent and culture-dependent methods were used to determine the persistence of Hanseniaspora uvarum, Candida sp. EJ1, and Saccharomyces cerevisiae populations within wine fermentations treated with inhibitory levels of sulfur dioxide. Upon addition, SO_2 completely inhibited growth of Hanseniaspora and Candida populations on enrichment media; however, PCR and RT-PCR signatures of each species persisted, in some cases, throughout the complete fermentation (as long as 20 days). PCR-DGGE and RT-PCR-DGGE profiles of yeasts present in the fermentations also indicated persistence of Hanseniaspora and Candida populations after their respective plating populations disappeared. This study demonstrates that molecular signatures of non-Saccharomyces yeasts can remain in wine fermentations treated with SO_2 long after those populations become nonculturable.