Optimization for the Production of Deoxynivalenol and Zearalenone by Fusarium graminearum Using Response Surface Methodology

Fusarium mycotoxins deoxynivalenol (DON) and zearalenone (ZEN) are the mostcommon contaminants in cereals worldwide, causing a wide range of adverse health effects onanimals and humans. Many environmental factors can affect the production of these mycotoxins.Here, we have used response surface methodology (RSM) to optimize the Fusarium graminearumstrain 29 culture conditions for maximal toxin production. Three factors, medium pH, incubationtemperature and time, were optimized using a Box-Behnken design (BBD). The optimizedconditions for DON production were pH 4.91 and an incubation temperature of 23.75 °C for 28 days,while maximal ZEN production required pH 9.00 and an incubation temperature of 15.05 °C for 28days. The maximum levels of DON and ZEN production were 2811.17 ng/mL and 23789.70 ng/mL,respectively. Considering the total level of DON and ZEN, desirable yields of the mycotoxins werestill obtained with medium pH of 6.86, an incubation temperature of 17.76 °C and a time of 28 days.The corresponding experimental values, from the validation experiments, fitted well with thesepredictions. This suggests that RSM could be used to optimize Fusarium mycotoxin levels, whichare further purified for use as potential mycotoxin standards. Furthermore, it shows that acidic pHis a determinant for DON production, while an alkaline environment and lower temperature(approximately 15 °C) are favorable for ZEN accumulation. After extraction, separation andpurification processes, the isolated mycotoxins were obtained through a simple purification process,with desirable yields, and acceptable purity. The mycotoxins could be used as potential analyticalstandards or chemical reagents for routine analysis.