THE USE OF GENETICALLY MODIFIED SACCHAROMYCES CEREVISIAE STRAINS IN THE WINE INDUSTRY

The inoculation of selected pure yeast cultures into must is an oenological practice established since the 1970s, in order to produce wine with desirable organoleptic characteristics and to guarantee the homogeneity of successive vintages. Nowadays, most of European wine production relies on the use of such commercial starter yeasts that were selected mainly due to their good fermentation performance. Extensive biogeographical surveys over years and the evaluation of the fermentative flora of a given viticultural region were the point of departure for further strain selection and improvement programmes. However, the natural availability of yeast strains possessing an ideal combination of oenological characteristics is improbable. In the years following the publication of the Saccharomyces cerevisiae genome sequence (Goffeau et al. 1996), new genetic tools turned the construction of GMY strains into a great challenge. Currently, numerous research laboratories worldwide have obtained engineered strains capable of improving, e.g. processing efficiency, fermentation performance and wine’s sensory quality. Their performance under oenological conditions has also been extensively evaluated. A future introduction of GMY also requires, in agreement with current legislation, a detailed safety and environmental impact evaluation, and strains obtained by self-cloning, based on the use of host-derived genetic material, are most likely to receive approval. However, the critical attitudes of consumers towards the use of genetically modified yeasts for wine production have not changed significantly during the last 10 years, and are the most relevant reason for the absence of recombinant strains in the wine industry. This work makes a global analysis of recent advances regarding the importance and implications of the use of genetically modified yeast strains in the wine industry. We consider various aspects such as the strategies used for the construction of strains with respect to current legislation requirements, the environmental risk evaluations concerning the deliberate release of GMY strains, the most relevant and sensitive methods for the detection of recombinant DNA and protein, and the reasons behind the critical attitudes of consumers towards the application of such strains. Follow the link on the right to download the full text of this article