Pectinolytic Yeast <i>Saccharomyces paradoxus</i> as a New Gene Pool for Winemaking

Abstract

Abstract—A large-scale screening of pectinolytic activity in the yeast Saccharomyces paradoxus isolated from various natural sources in Europe, Asia, North America, and the Hawaiian Islands was carried out. Of the 98 studied strains, pectinolytic activity was absent only in five Hawaiian and two European strains. Most strains were able to secrete active endo-polygalacturonase. North American strains UCDFST 52-225, UCDFST 61-359, UCDFST 61-220, 95-3, and UCDFST 62-186 had very high pectinolytic activity, comparable to or even higher than that of the experimentally obtained tetraploid strain S. cerevisiae VKPM Y-718. Comparative analysis of the nucleotide and amino acid sequences of pectinase genes showed that the North American and Far Eastern populations of S. paradoxus were more genetically diverse than the European and Hawaiian ones. Phylogenetic analysis confirmed the species specificity of the PGU genes of Saccharomyces yeasts. Of the eight Saccharomyces species, high pectinolytic activity is characteristic of S. bayanus and S. paradoxus. Five North American strains with the highest pectinolytic activity are of interest for further molecular genetic studies and breeding work with wine yeasts. The ecological role of endo-polygalacturonase is discussed.