Cyclopiazonic acid gene expression as strategy to minimizing mycotoxin contamination in cheese

The objective of this study was to evaluate the influence of pH, aw, and temperature on expression of dmaT, which encodes the enzyme dimethylallyl tryptophan synthase involved in the biosynthesis of CPA. We assayed three Penicillium strains, P. commune CBS311 and CBS341 and P. camemberti CBS273, using reverse transcription real-time PCR. Our results showed that the expression patterns of the gene were influenced by strain and environmental conditions. The highest expression for the P. commune strains was observed at pH 6.0, 0.95 aw, at 25 or 30 ºC, depending on the strain. In contrast, P. camemberti CBS273 showed a lower dmaT expression with a maximum at 25 ºC, pH 5.0 and 0.95 aw. Correlation analysis indicated that the three toxigenic strains showed a strong correlation between the relative expression of the dmaT gene and concentration of CPA under conditions simulating cheese ripening. This method could be used to control CPA production in cheese by detection of dmaT expression.
Source: Fungal Biology - Category: Biology Source Type: research