Synthetic liquid media for the study of trichothecene biosynthesis regulation in <i>Fusarium graminearum</i>

The production of trichothecene is dependent on the yeast extract brands and lots. Synthetic medium is more suitable for elucidating the regulatory mechanism of mycotoxin biosynthesis. The use of synthetic medium with a single amino acid or polyamine as the sole nitrogen source could lead to an erroneous conclusion about the role of catabolism-related genes on secondary metabolism. Here, we report the development of a culture system that helps analyze the nutritional and/or genetic factors associated with trichothecene biosynthesis. By optimizing the nitrogen source and the initial pH of the synthetic medium, the suppressive effect of L-Thr catabolism on trichothecene production was demonstrated in the shortened period of manual pH adjustments of the culture medium. This culture system with different nitrogen concentrations and initial pHs was also useful for demonstrating the indispensability of FgAreA in trichothecene biosynthesis.