The Growth of Native Yeasts on Mozzarella Cheese Whey with the Resistance towards High Glucose and Ethanol Contents

Abstract

Abstract The objectives of the research were to determine the growth of native yeasts on mozzarella cheese whey with the resistance towards high sugar and ethanol contents. Native yeasts isolated from 1 ml mozzarella cheese whey that poured into modified Potato Dextrose Agar (Oxoid Ltd.) with the addition of 3% Yeasts Extract/YE (Kraft Foods) and 10 ppm amoxicillin. Yeast-like microorganisms isolated then purified and tested with RapID Yeasts Plus System and analyzed by ERIC (Electronic Code Compendium) http://www.remel.com/eric. The yeasts growth towards high glucose and ethanol was evaluated by growing yeasts in modified Nutrient Broth/NB (Oxoid Ltd.) added with 20 and 30% of glucose monohydrates or 20 and 30% of ethanol concentration and the optical density (OD) measured every 24h until 72h. The results showed that C. tropicalis, Tri.beigelii and Blast.capitatus were native yeasts that could isolated from mozzarella cheese whey. Despite positive growth trend on substrates with high glucose and ethanol concentrations, C. tropicalis and Blast.capitatus showed the best growth.