Titanium dioxide nanoparticles under heat-shock negatively modulate the Crabtree effect in Saccharomyces cerevisiae.

Abstract

The results confirm UE-ME3 strain as a Crabtree-positive yeast, since the addition of glucose to respiratory cells caused an increase of cell viability, alcoholic fermentative and glycolytic activities, repression of citrate cycle and respiratory chain, followed by a decrease in cell damages. The exposure of S. cerevisiae to TiO2-NP with a molecular diameter less than 100 nm under heat shock (28/40 °C), for 200 min has prevent the glucose-dependent transition from respiratory to respiratory-fermentative metabolism, as evidenced by maintenance of ADH enzyme activity near of detected in respiratory cells, as well as by lowest levels of cell viability, glycolytic, fermentative, and antioxidant activities and highest levels of oxidative stress, cell damages and more active respiratory metabolism.