Study of the growth of yeasts from feta cheese

The effects of various physicochemical parameters on the growth of three yeast strains were investigated, including: pH, sodium chloride content, water activity in the medium and temperature. All strains were unaffected by pH changes. Growth was optimal at pH 5.5, while these yeasts were able to develop within the pH 2.5-8 range. Suitable growth was obtained at temperatures of 4 degrees C-44 degrees C and the optimal temperature for growth was 32 degrees C for all three strains. Modelling of this latter parameter is described. Growth of microorganisms was considerably modified by increased NaCl or decreased water activity in the medium.