Mycotoxins Contamination In Plants

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1. Introduction

Most agriculture food and feed materials are generally found to be colonized by a broad range of mycotoxigenic molds, which includes Aspergillus flavus, A. parasiticus, A. niger, Penicillium, and Fusarium sp (Kumar, Basu, & Rajendran, 2008). Mycotoxins contamination in food and feed causes huge economic losses, besides causing serious health problems. Of the total harvested crops in the world, approximately 25–50% of them were contaminated with mycotoxin producing fungi and mycotoxins, and as these fungi grow well in tropical regions, they damage nearly 80% of the crops (Abdin, Ahmad, & Javed, 2010). The food-borne mycotoxins play a significant role in health and economy in Asian, African and other tropical countries (Wagacha …show more content…

Biological control of AFs appears to be the more promising approach for control of aflatoxins in both pre- and post-harvested crops. Different organisms like bacteria, yeasts and non-toxigenic Aspergillus fungi, have been tested for their ability in the control of aflatoxin producing fungi and aflatoxin contamination. In biological control, greater levels of reduction were achieved by the application of competitive non-toxigenic strains of A. flavus and/or A. parasiticus towards aflatoxin contamination in pre- and post-harvest crops. This approach is based on the premise that when high numbers of spores of the nontoxigenic strains are added to soil, they will compete with naturally occurring toxigenic strains for infection sites for growth and for essential nutrients (Dorner & Cole, 2002). The process accomplished as follows, spores of selected non-toxigenic isolates are coated onto the cracked barley or wheat particles in molasses, which provides an even inoculation, reduces dust and acts as an additional nutrient source. The nutrient substrate and the grown nontoxigenic spores are then spread on soil in which the crop is growing. Growth of the nontoxigenic fungus on the substrate produces a multiplier effect; spore growth increase overwhelmingly …show more content…

The strains must be incapable of producing both aflatoxin and cyclopiazonic acid, CPA could be produced by non toxigenic A. flavus strains used in the biocontrol. Native non-toxigenic A.flavus strains have been found effective to competitively exclude aflatoxin-producing A.flavus strains (Abbas, Zablotowicz, Bruns, & Abel, 2006; Horn & Dorner, 2011; Zhou et al., 2015) in the fields. In addition, because of ecological and regulatory reasons, the strains should also be isolated in an areas where biocontrol agents ultimately to be used. Non-toxigenic A. flavus isolates were found to be majorly associated with the deletions of a part or the entire aflatoxin gene cluster (Chang, Horn, & Dorner, 2005). Defects in the aflatoxin gene, pksA in A. flavus AF36 isolate of cotton seed is responsible for its non-toxigenic nature. Other reasons for non-toxigenic nature of Aspergillus attributes to large deletions in the aflatoxin gene cluster (Houshyarfard, Rouhani, Falahati-Rastega, Malekzadeh-Shafaroudi, & Mehdikhani-Moghaddam, 2014). PCR assays have revealed that A. flavus strains with entire aflatoxin gene cluster could not produce AFs (Yin et al., 2009). Hence, analysis of deletion within aflatoxin gene cluster can be an effective method to identify the non-aflatoxigenic Aspergillus

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