Isolation of a psychrotolerant Debaryomyces hansenii strain from fermented tea plant (Camellia sinensis) leaves

A psychrotolerant, halotolerant and alkalophilic yeast was isolated from fermented leaves of Camellia sinensis Kuntze, the tea plant. The yeast strain, named Tea-Y1, was both phenotypically and genotypically identified as belonging to the species Debaryomyces hansenii. This assignment was confirmed by scanning and transmission electron microscopy. The analysis of growth curves demonstrated the ability this yeast strain to grow in a temperature range between 4 degrees C and 28 degrees C, with an optimum of 23 degrees C. The ecology of this yeast in the C. sinensis phyllosphere, as well as its possible role in tea fermentation and storage, with particular reference to iced tea, are discussed.