Saccharomyces uvarum, a distinct group within Saccharomyces sensu stricto


*Corresponding author. Institute for Wine Biotechnology, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa. Tel.: +27 (21) 808 3770; Fax: +27 (21) 808 3771, E-mail address:


A natural subgroup (that we refer to as Saccharomyces uvarum) was identified, within the heterogeneous species Saccharomyces bayanus. The typical electrophoretic karyotype, interfertility of hybrids between strains, distinctive sugar fermentation pattern, and uniform fermentation characteristics in must, indicated that this subgroup was not only highly homogeneous, but also clearly distinguishable from other species within the Saccharomyces sensu stricto group. Investigation of the S. bayanus type strain and other strains that have been classified as S. bayanus, confirmed the apparent lack of homogeneity and, in some cases, supported the hypothesis that they are natural hybrids.