Molecular approaches for monitoring the activation of fungal secondary metabolite biosynthesis in relation to food environmental conditions

Fungi are very undemanding C-heterotrophic organisms. Nevertheless, the better the nutrient supply, the better the growth of the fungus. This however is not directly correlated to the onset of secondary metabolism, for example, mycotoxin biosynthesis, which often is activated or increased under nutrient limiting conditions or under conditions which impose abiotic stresses. This suggests that the biosynthesis of these secondary metabolites may support the adaptation to a certain, non-optimal and more stressful environment. Growth conditions in food environments are usually not optimal and may even be stressful for the fungus. Because of these complex external influences on fungal growth and the regulation of mycotoxins, predictions about food safety issues with regard to mycotoxin biosynthesis can only be made if a profound knowledge about the regulatory issues of the mycotoxin biosynthesis genes directly in the food is available.