Saccharomyces uvarum, a distinct group within Saccharomyces sensu stricto

A natural subgroup (that we refer to as Saccharomyces uvarum) was identifie d, within the heterogeneous species Saccharomyces bayanus. The typical elec trophoretic karyotype, interfertility of hybrids between strains, distincti ve sugar fermentation pattern, and uniform fermentation characteristics in must, indicated that this subgroup was not only highly homogeneous, but als o clearly distinguishable from other species within the Saccharomyces sensu stricto group. Investigation of the S. bayanus type strain and other strai ns that have been classified as S. bayanus, confirmed the apparent lack of homogeneity and, in some cases, supported the hypothesis that they are natu ral hybrids. (C) 1999 Federation of European Microbiological Societies. Pub lished by Elsevier Science B.V. All rights reserved.