Alumínio: ação tóxica sobre a levedura Saccharomyces cerevisiae PE-2 e o efeito protetor do ácido cítrico e magnésico.

Abstract

The current work aimed to study the deleterious effects of different aluminum concentrations in the production rate of CO2, growing of biomass, viability and germination of Saccharomyces cerevisiae PE-2 yeast and the protector effect of citric acid and magnesium. Six different experiments were conducted, using a synthetic YED medium (1.0% of extract of yeast strains and 2.0% of sucrose). Each experiment consisted of four treatments of aluminum in the form of AlCl3.6H2O, in the following proportion: 0, 50, 100, 150 mg/L. The first experiment meant to consider the control, pointing out only doses of aluminum. The 2nd, 3rd and 4th experiments pointed out different doses of aluminum in function of different doses of citric acid (100, 200 e 400 mg/L respectively). The 5th and 6th ones were enriched with magnesium (50 and 100 mg/L, respectively) with different doses of aluminum. Three repetitions were used for each treatment, the medium pH was standardized to 4.0. Whereas the established standards were tested every 2 hours, in the following breaks: 2, 4, 6, 8, 10, 12, 14 and 16 hours after the inoculation of the yeast in the synthetic medium. The obtained results were taken to the analyses of variance, when meaningful to the point of 5% to regression. It is concluded that the aluminum showed cytotoxicity in the development of yeast in equal or superior doses of 50 mg/L. The citric acid and the magnesium promoted protector effect of S. cerevisiae PE-2 in relation to the deleterious effect of aluminum. The use of citric acid and magnesium, even promoting a little drop of viability of the yeast, they clearly demonstrated their efficiency and use as a protection mechanism, minimizing the deleterious effect of aluminum.