Abstract
The gaseous fermentation in “Uni-shiokara” has frequently been caused by salt tolerant yeasts, resulting in its softening and loss of palatableness. Debaryomyces kioeckeri, D. hansenii, D. nicotianae and its variety, Hansenula anomala and Candida species were found in the normal products, white Saccharomyces rouxii BOUTROUX or a new species named Saccharomyces kyushuensis ZENITANI were isolated from all of the products spoiled by gaseous fermentation.
The possibilities of gaseous fermentation under high salt condition were tested with various kinds of yeasts (32 strains) and it was found that the fermenters in such condition were all of Zygosaccharcmyces species (7 strains) and Torulaspora sp. M3 (Table 1). But as Torulaspora sp. M3 was very slow in fermenting, we consider Zygosaccharcmyces species chiefly responsible for the gaseous fermentation of “Uni-shiokara” Lodder & van Rij (1952) rejected the genus Zygosaccharcmyces and included the species brought to this genus in the genus Saccharomyces. According to their classification, the yeasts causing gaseous fermentation in “Uni-shiokara” are Sacchar omyces rouxii and Saccharcmyces kyushuensis. Some of their physiological properties are shown in table 2.
Such abnormal fermentation will be inhibited by adding vitamin K3.
