Results of mycotoxicological studies of the influence of sanitary and hygienic conditions on the synthesis of deoxynivalenol by the micromycete F. graminearum on various grain substrates

Today, fusariotoxins play an increasing lyimportant role in the pathology of farm animals, among which deoxynivalenol plays an important role. Deoxynivalenol (DON) is one of the most common fusariotoxins. It affects the health of animals that consume contaminated feed, and can lead to various metabolic disorders, disrupting the body's homeostasis. One of the main effects of deoxynivalenol is that it stimulates the production of anti-inflammatory cytokines, which in turn causes the acute phase of inflammation in animals. In addition, deoxynivalenol leads to a decrease in appetite and can cause hypophagia in animals, which in turn leads to a decrease in daily gains. The direction of the conducted research is aimed at identifying the optimal substrate for the synthesis of deoxynivalenol and its maximum accumulation by the fungus F. graminearum, and also established the optimal parameters for the synthesis of mycotoxin (cultivation temperature, substrate humidity, cultivation period). Grains of the following crops were used as substrates: wheat, rice, corn, barley, oats, rye, millet, peas, soybeans, sunflower, mustard, rapeseed, buckwheat, and flax. Deoxynivalenol in samples was determined by thin-layer chromatography. The production of deoxynivalenol was studied in the temperature ranges of 4, 17, 24, and 28 °C; humidity of the substrate in the range from 14–90% and the duration of cultivation from 1 to 4 weeks. The mycotoxin-producing activity of the fungus F. graminearum isolate 195/1 was largely determined by the studied parameters. The maximum amount of deoxynivalenol was produced at a temperature of 24 ºС, a substrate humidity of 50%, and a duration of cultivation of 24 days. Of the tested substrates, rice was the best for deoxynivalenol production. The obtained results serve as a basis for possible prediction of feed contamination with deoxynivalenol and, in general, will allow to optimize measures to combat mycotoxicosis and thus minimize the possible risks of mycotoxin poisoning of people and animals. Key words: F. graminearum, grain substrates, deoxynivalenol, cultivation temperature, substrate humidity, duration of cultivation.