Quality improvement and fermentation control in beer

Institute of Chemical Technology Prague, Prague, Czech Republic 

Protoplast fusion is a techniqne that enables the asexual combination of two complex genomes. However, similarly to conventional breeding, the final result is uncertain because of unpredictable gene transfer with little or no understanding of the specific genetic pertnrbations (Piddocke Olsson, 2010). As an example of protoplast fusion, the conversion of non-flocculent brewer s yeast to a flocculent one by electrofusion can be cited (Urano, Sahara, Koshino, 1993 Urano, Sato, Sahara, Koshino, 1993). 

Yeast flocculation is a reversible and asexual process of cell aggregation, which plays an important role in sedimentation to the bottom of the fermentation vessel. Adhesins or flocculins, the cell-wall glycoproteins, are responsible for flocculation, together 

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