Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 12/15/2010
Publication Date: N/A
Citation: N/A Interpretive Summary: Fungally produced mycotoxins such as the aflatoxins, trichothecenes, and fumonisins account annually for hundreds of millions of dollar equivalents (internationally) of crop losses, as well as loss of health and human life across the world, thus affecting world health, trade and food security on a global basis. Also of concern is the connection between a lack of food security and social unrest across the world. Thirty countries experienced food-related riots in 2008, half in Africa. Elimination of mycotoxin concerns through application of innovative research solutions could prevent food losses, unsafe food grains, and losses in human life as threats to world food security. The identification of fungi that produce these toxins is very vital to our ability to prevent toxin contamination of food and feed both pre-harvest and post-harvest. This paper provides a review of the various ways in which these fungi can be identified morphologically and genetically.
Technical Abstract: Mycotoxins are natural products produced by fungi that evoke a toxic response in higher vertebrates and other animals when ingested at low concentrations. These compounds are low-molecular weight, secondary metabolites derived primarily from amino acids, shikimic acid or malonyl CoA. Mycotoxins are generally produced in the mycelia of filamentous fungi, but can accumulate in specialized structures of fungi such as conidia or sclerotia as well in the surrounding environment. A specific mycotoxin may be produced by several fungal species, just a single fungal species or even by a specific strain of a fungal species. The toxic effects of these mycotoxins are as diverse as the number of fungal species that make them. Some mycotoxins have acute toxic effects, especially when ingested at high concentrations, whereas others have toxic effects after long-term exposure to lower doses (chronic effects). Over three hundred mycotoxins have been identified, and almost all of these are produced by fungi of just three genera, namely Aspergillus, Fusarium and Penicillium. The former two genera are the ones most commonly found in the maize grain chain throughout the world producing the mycotoxins aflatoxins (by Aspergillus flavus and A. parasiticus) and fumonisins (by Fusarium verticillioides). The identification of these fungi using morphological or genetic means is discussed in this article.