From yeast genetics to biotechnology

Abstract

Roots of classical yeast genetics go back to the early work of Lindegreen in the 1930s, who studied thallism, sporulation and inheritance of wine yeast strains belonging to S. cerevisiae. Consequent mutation and hybridization of heterothallic S. cerevisae strains resulted in the discovery of life cycle and mating type system, as well as construction of the genetic map. Elaboration of induced mutation and controlled hybridization of yeast strains opened up new possibilities for the genetic analysis of technologically important properties and for the production of improved industrial strains, but a big drawback was the widely different genetic properties of laboratory and industrial yeast strains. Genetic analysis and mapping of industrial strains were generally hindered because of homothallism, poor sporulation and/or low spore viability of brewing and wine yeast strains [1, 2]. In spite of this, there are a few examples of the application of sexual hybridization in the study of genetic control of important technological properties, e.g. sugar utilization, flocculation and flavor production in brewing yeast strains [3] or in the improvement of ethanol producing S. cerevisiae strains [4]. Rare mating and application of karyogamy deficient (kar-) mutants also proved useful in strain improvement [5]. Importance of yeasts in biotechnology is enormous. This includes food and beverage fermentation processes where a wide range of yeast species are playing role, but S. cerevisiae is undoubtedly the most important species among them. New biotechnology is aiming to improve these technologies, but besides this, a completely new area of yeast utilization has been emerged, especially in the pharmaceutical and medical areas. Without decreasing the importance of S. cerevisiae, numerous other yeast species, e.g. Kluyveromyces lactis, Hansenula polymorpha, Pichia pastoris, Schizosaccharomyces pombe and Yarrowia lipolytica have gained increasing potentialities in the modern fermentation biotechnology [6]. Developments in yeast genetics, biochemistry, physiology and process engineering provided bases of rapid development in modern biotechnology, but elaboration of the recombinant DNA technique is far the most important milestone in this field. Other molecular genetic techniques, as molecular genotyping of yeast strains proved also very beneficial in yeast fermentation technologies, because dynamics of both the natural and inoculated yeast biota could be followed by these versatile DNA-based techniques.

The yeast sphingolipid signaling landscape

“…Mating and sporulation in yeast have largely been studied as genetic tools (Elrod et al, 2009) and in the context of beer and wine production (Maráz, 2002). This category pertains to yeast mating and sporulation pathways, including defective pheromone uptake, defective mating, and defective sporulation.…”

Progress in Metabolic Engineering of Saccharomyces cerevisiae

“…These have been, in part, quite successful, particularly when a bacterial ␣-acetolactate decarboxylase was expressed in yeast. These studies mostly date to the 1980s; the reader is referred to several prior reviews (71,113,217,259,359). Interestingly, diacetyl production has never presented a problem in wine production.…”

A homozygous diploid subset of commercial wine yeast strains

“…Wine yeasts are considered to be genetically complex (Pretorius 2000;Maraz 2002) and some appear to be unstable (Ibeas and Jimenez 1996;Ramirez et al 2004). Although many strains are diploid, some are aneuploid and some polyploid (Pretorius 2000).…”