Nitrogen is essential to extend the fermentative growth of Saccharomyces cerevisiae in the presence of isoproturon

Abstract

In nature and in industrial musts, pollutants are available in a complex mixture where some specific microorganisms are able to mineralize or degrade them in more basic and less harmful compounds to the environment. Isoproturon, a phenylurea herbicide, is an environmental contaminant poorly degraded in soils and aquifers, reaching levels considered toxic by European legislation. Thus, it is urgent to discover microorganisms able to degrade or eliminate these pollutants in situations of accidental or systematic contamination, establishing the best culture conditions. Therefore, in this work it was intended to evaluate if peptone, a nitrogen source, essential for yeast growth, amends the extension of fermentative phase of a wild-type strain S. cerevisiae UE-ME3 caused by isoproturon. The results show that this wild-type yeast grown in peptone starvation conditions, in presence of 100 µM isoproturon, started early the fermentative-respiratory transition.