Abstract
On the basis of genetic analysis, molecular karyotyping and sequence analyses of the 18S rRNA and internal transcribed spacer (ITS) region, three new Saccharomyces species are described, Saccharomyces cariocanus (with type strain NCYC 2890(T)), Saccharomyces kudriavzevii (with type strain NCYC 2889(T)) and Saccharomyces mikatae (with type strain NCYC 2888(T)). Genetic and molecular analyses did not confirm the previously observed conspecificity of Saccharomyces paradoxus and S. cariocanus. The latter species exhibits post-zygotic isolation from representative strains from all known geographical populations of S. paradoxus: European, Far-East Asian, North American and Hawaiian.