**Electrophoresis Application in Ecological and Biotechnological Aspects**

**1** 

*Spain* 

**Application of Gel Electrophoresis** 

**Yeast and to Improve Winemaking** 

María Esther Rodríguez, Laureana Rebordinos, Eugenia Muñoz-Bernal,

Yeasts are unicellular fungi that are frequently used as a model and tools in basic science studies. This is the case of the laboratory yeasts *Saccharomyces cerevisiae*, which were introduced in the laboratory for genetics and molecular studies in about 1935. There is, however, a second type of yeast comprising those used in industrial processes, for example, in brewing, baking and winemaking. Wine yeast and its properties have been known to humans for as long as civilizations have existed, and the earliest evidence of this yeast has

Most wine yeast strains are diploid and have a low frequency of sporulation. Another important characteristic of wine yeasts, and those used in other industries, is their highly polymorphic chromosomes: their genetic constitution is affected by the frequent and extensive mutation they undergo. These effects include (i) aneuploidy, (ii) polyploidy, (iii) amplification and deletion of chromosomal region or single gene, and (iv) the presence of hybrid chromosomes. The chromosomal polymorphism obtained by applying the technique known as pulsed field gel electrophoresis (PFGE) has been used to characterize and to

In the wine industry, knowledge of the yeast species responsible for the alcoholic fermentation is important because these yeasts with their metabolism contribute significantly to the organoleptic characteristics of the finished wine (Fleet, 2008). The diverse range of yeasts associated with the vinification process can be classified in two groups. The first group is formed principally by the genera *Hanseniaspora*, *Torulaspora*, *Metschnikowia*, *Candida*, *Zygosaccharomyces*, etc. These yeasts initiate spontaneous alcoholic fermentation of the must, but they are soon replaced by the second group, formed by *Saccharomyces* yeasts, which are present during the subsequent phases of the fermentation until it is completed. Within the genus *Saccharomyces* the species most relevant for the fermentation process are *S. cerevisiae* and *S. bayanus* var. *uvarum*; this is because they have become of interest for their biotechnological properties. However, there is currently increasing interest in the non-*Saccharomyces* yeasts for the development of innovative new styles of wine (Viana et al.,

**1. Introduction** 

been dated to Neolithic times (Mortimer, 2000).

classify strains that belong to the same species.

Francisco Javier Fernández-Acero and Jesús Manuel Cantoral *Microbiology Laboratory, Faculty of Marine and Environmental Sciences* 

**Techniques to the Study of Wine** 

*University of Cadiz, Puerto Real* 
