Abstracto

Effects of ã-ray irradiation on oxidoreductase activities: Yeast alcohol-dehydrogenase and soybean lipoxygenase

Mejri Sonia, Ben Akacha Najla, Mabrouk Yassine, Kotti Faten,Jerbi Taieb, Saidi Mouldi, Gargouri Mohamed

The effect of ionizing radiations was known to increase the conservation length of products, to improve their physicochemical properties and/or to enhance the rate of several reactions. The effect of 60Co-gamma-ray irradiation on two oxidoreductase activities was investigated: alcoholdehydrogenase from yeast and lipoxygenase from soybean. The results showed that the ã-ray doses between 10 and 70 Gy allowed to increase the specific alcohol dehydrogenase activity by 1.45 fold. It was also concluded from the results that the effect of irradiation on alcohol dehydrogenase activitywasmore importantwhen yeast cells were irradiated before enzyme extraction. In this case, alcohol dehydrogenase activity was enhanced by twelve fold compared to the activity tested in the irradiated enzymatic extract. In contrast, the gamma irradiation doses used to activate the alcohol dehydrogenase did not affect the soybean lipoxygenase activity. Although the belonging of lipoxygenase and alcohol dehydrogenase to the oxidoreductase class, these enzymes have different sensitivities award the gamma ray irradiation.