Recombinant hydroperoxide lyase for the production of aroma compounds: Effect of substrate on the yeast Yarrowia lipolytica

Abstract

The aim of this study was to investigate the action mechanism of linoleic acid hydroperoxides (HPOD), which are the major substrates of hydroperoxide lyase for the production of flavour compounds, on the yeast Yarrowia lipolytica by evaluating their effect on the oxidative state of the cells. The total antioxidant capacity (TAC) and the activity of the main antioxidant enzymes, such as glutathione reductase, glutathione peroxidase and superoxide dismutase, of cells treated with HPOD were studied. The potential role of intracellular glutathione, including reduced glutathione (GSH) and oxidized glutathione (GSSG), in conferring HPOD resistance was also been examined. The experimental findings showed that HPOD induced a concentration-dependent decrease in TAC which could be an indication of the oxidative stress. The decrease in glutathione reductase activity and the increase in glutathione peroxidase and superoxide dismutase activities, following the treatment with HPOD may suggest a possible detoxification role for these enzymes. An important role of the intracellular glutathione in the cellular responses to HPOD was demonstrated, since the treatment of the cells with an increase in HPOD-concentration resulted by shifting the redox balance GSH/GSSG of the cells to a more oxidized state. Moreover, the increasing membrane permeability of the HPOD-treated cells, support the hypothesis that HPOD can interact with the membrane and penetrate into the cells for the induction of any oxidative stress. © 2007 Elsevier B.V. All rights reserved.