Study On Extraction And Purification Of Zearalenone And Toxigenicity Of Producing Strains

Zearalenone was a highly damaging mycotoxin, which was a harmful substance checked in grain and feed. In order to ensure the safety of grain and feed and so on. The pollution situation of zearalenone need be monitored all the year around by testing institutions, research institutions and related enterprises. The chromatography and immunoassay used to test zearalenone both need standard material as a contrast, therefore, we need a large amount of high purity zearalenone standards in this field. However, at present, zearalenone standards were not localization, most of zearalenone standards were depended on foreign imports, not only the price was very expensive, but also the process was very complicated. Thus, study on zearalenone extraction and purification and its performance of mycotoxin-producing strains had important practical significanc for domestic production.The research content mainly includes the following aspects in this paper:1. The pollution of moldy grain for zearalenone extraction and purification:Moldy corn was choosed as the test samples, the method of preparation of ZEN was established by optimizing the extraction and purification methods, the result as following: crushing time corn sample was 180 s, when using the volume fraction of 70% methanol as extracting agent of ZEN, ZEN additive recovery rate can reach 97.01%. Although this method can effectively extract of ZEN, ZEN content in moldy corn samples were limited, so it was different to produce for this method at large-scale mass2 The optimal culture conditions of mycotoxin-producing strains:Fusarium graminearum strain was considered as culture strain, the optimal culture condition was analyzed. The optimal culture medium for Fusarium graminearum were glucose 60 g/L, peptone 20 g/L, Na NO3 6.0 g/L, KNO3 1.5 g/L, K2HPO4·3H2O 1.0 g/L, yeast extract paste 1.0 g/L, KCl 0.5 g/L, Mg SO4 0.5 g/L, Fe2(SO4)3 0.025 g/L, ultrapure water 1.0 L. When shaking speed 92 r/min, illumination 10 h/d, culture temperature was 22.9 ℃ and culture time were 20 days, the concentration of ZEN could reach to 249.80 μg/L, to use this cultivation condition of Fusarium graminearum is suitable for mass production.3. The preparation of ZEN in liquid culture:To obtain highly purified zearalenone, the mycotoxin was extracted and then purified from the fermented liquid of Fusarium graminearum in this study using different extraction solvents and chromatographic columns. The results demonstrated that benzene was recognized to be the best single extraction agents, which yield could reach up to 73.20%. Daisogel reverse phase chromatography column was better chosen to purify zearalenone, because its yield was up to 69.30% and the numbers of impurity peaks significantly decreased. The findings of this study can demonstrate the extracted and purified of zearalenone from Fusarium graminearum fermented liquid had a good effect.