Toxins are defined as poisonous substances, proteins or secondary metabolites, which can be produced by prokaryotic or eukaryotic organisms and which can cause disease or even have lethal effects on other organisms after contact or uptake. Toxins of microbial origin serve different functions in various environments. Terrestrial and marine predators may use toxins to kill their prey. Bacteria and fungi may produce antimicrobial compounds to compete for nutrients or to occupy particular ecological niches. Necrotrophic plant pathogens often produce toxins to kill plant tissues in advance of colonizing them, whereas obligate biotrophic pathogens are dependent on living host cells and have often lost the ability to produce toxins. However, of many toxins that are lethal to animals and humans, we do not know their natural function. Mycotoxins can contaminate feed and food and …