A serological typing method for salt-tolerant yeasts in soy sauce mashes.

Abstract

The serological grouping of yeasts in soy sauce mashes was attempted. Twenty-one representative strains of salt-tolerant yeasts isolated from soy sauce mashes were divided into 5 groups as to the differences in the agglutination patterns with 4 factor sera, 4, 10, 20 and 35. Furthermore, 2 other groups of yeasts were detected in soy sauce mashes. Some yeasts responsible for the characteristic flavor were included in the individual groups. Changes in the yeast-flora during the fermentation of soy sauce mashes could be monitored easily by means of the serological grouping system. Among Zygosaccharomyces rouxii strains isolated from soy sauce mashes, no differences in thermostable antigens or PMR spectra of cell wall polysaccharides were found. Over 95% of the moromi-mash yeasts that showed a positive reaction with factor serum 35 exhibited 4-ethyl-2-methoxyphenol (4EG) productivity.