Isolation and Characterization of Yeasts from Locally Available Foods

Abstract

A study was conducted to identify different isolates of yeasts which are prospective to be utilized in various industries from locally available foods. Altogether 24 yeast isolates were obtained from fermented fruits and vegetables (banana, cabbage, grapes, lime and mango), pudding, bee honey, toddy and fermented fish samples using the pour plate method. Characterization of the yeasts using several biochemical tests (urease, catalase, liquid carbon and nitrogen assimilation and sugar fermentation tests) revealed that this pool was composed with yeast strains belong to genera of Saccharomyces, Kluvyeromyces, Candida, Pseudozyma, Cryptococcus, Rhodotorula and Debaryomyces. The most effective lactose fermenters were identified as viable candidates for bioethanol production and for manufacturing fermented dairy products for lactose intolerant people. Yeasts with the highest biomass production were suggested as the best viable candidates for industrial single cell protein production using whey, the major byproduct of the dairy industry. The five thermo-tolerant yeasts (Y55, Y57, Y58, Y59 and Y70) and Y069 which was optimally active under 10C were recognized as suitable for industrial applications. The isolates tolerant for high osmotic pressure conditions were identified as potential isolates to be used in highly concentrated food products. Sugarcane juice was recognized as a possible medium for the cultivation of these yeasts in industrial settings. The beneficial yeasts forecasting in this study are expected to screen using molecular biological methods to utilize them in industrial applications.