Читать книгу Handbook of Enology: Volume 1 - Pascal Ribéreau-Gayon - Страница 33

As mentioned in the introduction to this chapter, yeasts constitute a vast group of single‐celled fungi that are taxonomically heterogeneous and very complex. Hansen's first classification at the beginning of the 20th century only distinguished between sporogenous and asporogenous yeasts. Since then, yeast taxonomy has been the subject of considerable research. This research has been gathered in successive works, thus progressively creating the classification known today. The previous enological textbook from the University of Bordeaux (Ribéreau‐Gayon et al., 1975) was based on Lodder's (1970) classification. Between the last edition of that book and the previous classification (Lodder and Kregger‐Van Rij, 1952), the designation and classification of yeasts had already changed profoundly. In this book, we use the latest classification, given by Kurtzman et al. (2011), relying on the recent methods of molecular biology and genome analysis for the demarcation of species and genera.

Rules concerning the taxonomy of yeasts and other fungi fall under the International Code of Nomenclature for algae, fungi, and plants. Its most recent version was adopted in 2005, during the 17th International Botanical Congress in Vienna, Austria (http://ibot.sav.sk/icbn/main.htm). According to the current taxonomy, genera are classified in alphabetical order according to four groups: teleomorphic ascomycetes, anamorphic ascomycetes, teleomorphic basidiomycetes, and anamorphic basidiomycetes. The terms “teleomorphic” and “anamorphic” refer, respectively, to the sexual and asexual forms.

Taking into account synonymy and physiological races (varieties of the same species), at least 4,000 names for yeasts have been used since the 19th century. However, the species of yeasts likely to be highly present in the grape and in wine, intervening as an agent of alcoholic fermentation or responsible for wine spoilage, are more limited. Table 1.1 presents the classification of the main order Saccharomycetales, to which grape and wine yeasts belong. Basidiomycetes are not found in this table, as none of the main genera of grapevine and grape yeasts belong to that phylum.