Use of a PGU1 recombinant Saccharomyces cerevisiae strain in oenological fermentations

摘要

Aim: The aim of this work was the construction of an oenological Saccharomyces cerevisiae strain able to overexpress the PGU1 gene in order to be used in trial fermentations. Methods and Results: The recombinant strain is able to secrete an active endopolygalacturonase into the medium leaving its fermentation ability essentially unchanged. Wines obtained with the recombinant strain and the untransformed counterpart did not differ in their physicochemical parameters or major sensory characteristics. The time needed for wine filtration was dramatically reduced in wines elaborated with the PGU1 recombinant strain, and was comparable to the filtration time shown by wines elaborated from must supplemented with fungal pectolytic enzymes. Conclusions: The oenological strain constructed in this work secretes an endopolygalacturonase into the wine in an efficient manner, resulting in an improvement in wine filtration but preserving wine typicality and keeping the methanol levels unchanged. Significance and Impact of the Study: The PGU1 recombiant strains could be used in oenological fermentations as an alternative to commercial pectolytic enzymes of fungal origin.