Evidence of a bimodal effect on Saccharomyces cerevisiae UE-ME3 by vanadium (V) stress - a dual response to different V2O5 medium concentration detected in the rate growth, GSH/GSSG, G6PD, CAT T and GR enzymatic activities

The aim of this work was to evaluate the effects of five V2O5 medium concentrations ranging from 0.5 to 2.0 mM on cell viability, redox status and antioxidants enzymes of wine yeast S. cerevisiae UE-ME3. A slightly decrease of yeast cells growth rate for 0.5 and 1.0 mM, and a significantly decrease for 1.5 and 2.0 mM were observed. Conversely, a significantly increase of G6PD activity and GSH/GSSG ratio for 0.5 mM V2O5, and a significantly decrease of GR and CAT T activities for 0.5 and 1.0 mM also occurs. Furthermore, for V2O5, ranging between 1.0 and 2.0 mM, we observed a significantly decrease of G6PD and GSH/GSSG ratio, occurring, at the same conditions a reverse effect on GR and CAT T activities, with a significant increase of GR for 1.5 and 2.0 mM. We suppose that bimodal response of S. cerevisiae to vanadium pentoxide, eventually mediated by NADPH and GSH level, rule cell death