italicus Saccharomyces norbensis Saccharomyces oleaceus Saccharomyces oleaginosuss Saccharomyces uvarum
a Interspecific hybrids.
The new classification by Kregger‐Van Rij (1984), based on Yarrow's work on percentages of guanine and cytosine bases in yeast DNA, brought forth another important change in the designation of Saccharomyces species. Only seven species continued to exist, while 17 names became synonyms of S. cerevisiae. As with the preceding yeast classification, these yeast were differentiated by their sugar utilization profile (Table 1.4), and some authors considered them to be races or physiological varieties of S. cerevisiae. However, this was nothing more than an artificial taxonomy without biological significance. Enologists took the habit of adding the varietal name to S. cerevisiae to designate wine yeasts: S. cerevisiae var. cerevisiae, var. bayanus, var. uvarum, var. chevalieri, etc. In addition, two species, bailii and rosei, were removed from the genus Saccharomyces and integrated into two other genera to become Zygosaccharomyces bailii and T. delbrueckii, respectively.
Based on recent advances in genetics and molecular taxonomy, the latest yeast classification (Kurtzman et al., 2011) and recent studies (Libkind et al., 2011) have again thrown the species delimitation of the genus Saccharomyces into confusion. There are now 10 species (Table 1.3). The species Saccharomyces paradoxus, Saccharomyces arboricolus, Saccharomyces mikatae, and Saccharomyces eubayanus include strains initially isolated from tree exudates, insects, and soil (Naumov et al., 1998, 2000a; Wang and Bai, 2008; Libkind et al., 2011). Using genome analysis, Redzepovic has nevertheless identified a high percentage of S. paradoxus in Croatian grape microflora in Redzepovic et al. (2002).
TABLE 1.4 Physiological Races of S. cerevisiae Grouped Under a Single SpeciesS. cerevisiae by Yarrow and Nakase (1975)
| Fermentation | ||||||
|---|---|---|---|---|---|---|
| Ga | Su | Ma | Ra | Me | St | |
| Saccharomyces | ||||||
| aceti | − | − | − | − | − | − |
| bayanus | − | + | + | + | − | − |
| capensis | − | + | − | + | − | − |
| cerevisiae | + | + | + | + | − | − |
| chevalieri | + | + | − | + | − | − |
| coreanus | + | + | − | + | + | − |
| diastaticus | + | + | + | + | − | + |
| globosus | + | − | − | − | − | − |
| heterogenicus | − | + | + | − | − | − |
| hienipiensis |
|
