CONVERSION OF A NON-FLOCCULANT BREWERS-YEAST TO FLOCCULANT ONES BY ELECTROFUSION .1. IDENTIFICATION AND CHARACTERIZATION OF THE FUSANTS BY PULSED FIELD GEL-ELECTROPHORESIS

Conversion of non-flocculent brewer's yeasts to flocculent ones was ca rried out by electrofusion using Saccharomyces cerevisiae (FLO5), and eight of the fusants obtained were characterized by pulsed field gel e lectrophoresis. Flocculation activity of fusants was various and inter mediate between that of the parent cells [Grade 0: a brewer's yeast, G rade 1: F(18) and F(39), Grade 2: F(26), F(59), F(100) and F(107), Gra de 3: F(74), Grade 4: F(80), Grade 5: S. cerevisiae]. The electrophore sis showed that DNA patterns of all fusants were closely related to th ose of a brewer's yeast except for some differences. Inclination of ch romosomal DNA in the fusants to the brewer's yeast was F(18) > F(100), F(107), F(59) > F(39) > F(26) > F(74) > F(80) and there was a good co rrelation with the results of flocculation activities in the fusants.