Effect of gamma-ray on activity and stability of alcohol-dehydrogenase from Saccharomyces cerevisiae

The effect of γ-ray irradiation on alcohol-dehydrogenase activity of yeast was investigated. The results suggested that low doses of γ-ray (10 and 20 Gy) significantly increased the enzyme activity. This work also describes the impact of irradiation on immobilization efficiency of biocatalyst entrapped on to alginate gel beads. When yeast irradiated to a dose of 20 Gy was immobilized, ADH stability was improved up to 1.4 times at 45 °C compared to the immobilized non-irradiated cells. Also, the irradiated biocatalyst, when immobilized, can be reused more than eight times in oxidation reaction of ethanol. This preparation also permitted to reach high yields of immobilization (79%) and activity (88%).