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Title
Abstract
In this paper, some technological properties of 8 strains of Yarrovia lipolytica yeast and 13 strains of Debaryomyces hansenii yeasts were analyzed. The analysis focused on the level of their proteolytic and lipolytic activities, their limited ability to generate biogenic amines and pigment, and, also, on the mutual interactions between the strains of those two species. The yeast strains of Y. lipolytica (PII6a, PII6c and JII1c) demonstrated the best ability to synthetise both the extra- and the intracellular hydrolases. As regards the D. hansenii yeast strains, only a minor intracellular peptidase activity thereof was found, and, in the majority of cases, an extracellular lipolytic activity. Only the Y. lipolytica yeast strains showed an ability to produce pigment, except for the PII6a, PII6b, and PII6c strains. None of the strains of the two species analyzed degraded histidine to histamine, however, the Y. lipolytica yeast showed an ability to produce more biogenic amines. All the D. hansenii yeast strains produced killer toxins. Only three strains of Y. lipolytica (JII1a, JII1b, JII1c) demonstrated resistance to those killer toxins.
Keywords
proteolytic activity, yeast starters in cheese making, Yarrovia lipolytica, Debaryomyces hanseni