Authors: Angela Xufre Helena Albergaria Francisco Gírio Isabel SpencerMartins
Publish Date: 2010/09/03
Volume: 38, Issue: 1, Pages: 127-132
Abstract
The industrial use of starter cultures containing a consortium of different strains from the same species is nowadays seen as a possible strategy to enhance the organoleptic complexity of wines To assess the relative contribution of each strain to the final product it is essential to quantify population evolution during the wine fermentation process which requires strainspecific methods to identify and differentiate each strain In the present study a molecular method based on analysis of the polymorphisms exhibited by the PCRamplification of the delta regions of three Saccharomyces cerevisiae strains was developed A set of three pairs of primers delta1–delta2 delta12–delta2 delta12–delta21 was used for each strain and analysis of the resulting polymorphism patterns showed that the delta12–delta2 primer pair exhibited the highest resolution and discriminatory power Thus this pair of primers was selected to monitor the population evolution of a laboratoryscale wine fermentation performed in synthetic grape juice that was inoculated with similar amounts of each strain The results showed that all strains grew together during the exponential growth phase 2–3 days and maintained high cell density values 106–107 cfu ml−1 throughout the stationary growth phase without significantly changing their relative population proportion thus indicating that each strain can influence the chemical composition and final flavor of wine albeit at different levels This study also showed that PCRamplification of DNA delta sequences of S cerevisiae strains is a reproducible strainspecific and simple method that can be used successfully to monitor yeast strain population dynamics during wine fermentationsThe present work was supported by project POCTI/AGR/39974/2001 AX was a beneficiary of a PhD fellowship Praxis XXI/BD/21366/99 funded by Fundação para a Ciência e Tecnologia Portugal The authors would like to express their gratitude to João Inácio for his review of the paper
Keywords: