ANALYSIS OF ETHANOL TOLERANCE OF THE YEAST MUTANTS DEVELOPED BY ACRIDINE ORANGE MUTATION

摘要

The investigation was carried out to isolate yeast strains from their natural habitats and to screen them for ethanol tolerance. A total of 5 yeast strains were isolated from various sources like Grape, Apple, Distillery effluents. Standard yeast andDry yeast cultured on Yeast Extract Potato Dextrose Agar media. All of these five samples were used to isolate five strains of yeast identified as Saccharomyces strains based on colony type and cell morphology and budding characters. Saccharomyces species were screened for the ability to tolerate different ethanol concentrations from 8-14%. Growth in different ethanol concentrations varied from one strain to another. Mutation was induced with intercalating agent like Acridine Orange with four differentconcentrations, (0.25, 0.50. 0.75 and 1 mg/mL). Yeast strains showed tolerance level from 8-14%. Mutated strain YMSY showed highest tolerance to ethanol stress and YMDY with lowest tolerance. Mutants showed decreased growth and tolerance under high ethanol stress compared to their original isolates.