Effects of some pesticides on two yeast strains Saccharomyces cerevisiae and Metschnikowia pulcherrima

Abstract

The effect of different concentrations (0-20 LMR) of six pesticides on the aerobic growth of two yeast strains (Saccharomyces cerevisiae, Metschnikowia pulcherrima) was analysed. The penconazole was shown as the most efficient and its effect was then studied under fermentative conditions. Saccharomyces cerevisiae appeared very sensitive under aerobiosis while the fermentative cultures seemed poorly affected. On the opposite, Metschnikowia pulcherrima was poorly affected under aerobiosis but was severely affected under fermentative conditions. The yields as well as the reaction rates decreased when initial concentrations of penconazole were increased. At least, it was shown that both strains were able to adsorb a certain ratio of the pesticide; but the pesticide was not degraded. Also for an initial value greater than 2 LMR, the residual quantity of the pesticide was above the admitted level.