MONITORING AND BIOCONTROL APPROACHES TO REDUCE THE IMPACT OF MYCOTOXINS IN CAMEL AND CATTLE FEED AND RELATED FOOD CHAIN

Abstract

The presence of fungi and their associated mycotoxins in agricultural commodities is a worldwide problem leading to mycotoxins contamination in feed and animal products. This results in mycotoxins' carry-over to human posing their health to risk. In this dissertation, sampling of feed, animal milk and meat was carried out from Qatari farms. The meat samples were collected from local butcher store to assess their content of mycotoxins. Mutli-mycotoxins were detected in the samples of feed and milk, and aflatoxins were detected in meat samples. However, none of the detected concentrations exceeded the European Union maximum regulatory limits. Since the majority of the animal feed collected were imported, Qatar has no direct control over the contamination in these commodities. Nonetheless, legislating local standards and preventive measures is imperative. As an implementation of biological strategies to control mycotoxigenic fungi and their mycotoxins, Qatari Bacillus strains isolated and identified were applied against mycotoxigenic fungi. Strains B. amyloliquefaciens 3CA and B. subtilis 3-A had exhibited a diverse antifungal activity against various mycotoxigenic strains. The bacterial strains possessed the ability of reducing fungal growth and the synthesis of their associated mycotoxins, in addition to down regulating the genes responsible for ochratoxin A biosynthesis. The bacterial antifungal metabolites were highly thermally stable and retained antifungal activity upon long storage. The bacterial metabolites were extracted and characterized as lipopeptides, and their antifungal activity was validated. Bacterial antifungal metabolites were applied in-vivo to protect cherry tomatoes from rotting by Alternaria. The bacterial metabolites exhibited excellent preventive and curative effect as the decaying incidence was significantly lower from the non-treated tomatoes. Yeast Candida glabrata wideranged antifungal VOCs were applied in-vivo to protect grapes and kumquat fruits from fungal infections. The metabolites were efficient in inhibiting A. niger and Penicillium occurrence to zero % decaying chance in grapes and 25% in kumquat. The antifungal VOCs were identified with GC-MS and the structure of the molecules was deduced. The metabolites of bacterial and yeast strains have the potential application in the field to protect the crops from post-harvest diseases as they are anticipated to be stable in harsh climatic conditions.