Mycotoxin-Producing Ability and Chemotype Diversity of Aspergillus Section Flavi from Soils of Peanut-Growing Regions in Iran

Abstract

Invasion of crops with Aspergillus flavus may result in contamination of food and feed with carcinogenic mycotoxins such as aflatoxins (AF) and cyclopiazonic acid (CPA). In the present study, distribution and toxigenicity of Aspergillus flavus and A. parasiticus in soils of five peanut fields located in Guilan province, Northern Iran was investigated. From a total of 30 soil samples, 53 strains were isolated which all of them were finally identified as A. flavus by a combination of colony morphology, microscopic criteria and mycotoxin profiles. Chromatographic analysis of fungal cultures on yeast extract sucrose broth by tip culture method showed that 45 of the 53 A. flavus isolates (84.9 %) were able to produce either CPA or AFB 1 , while eight of the isolates (15.1 %) were non-toxigenic. The amounts of CPA and AFB 1 produced by the isolates were reported in the range of 18.2-403.8 lg/g and 53.3-7446.3 lg/g fungal dry weights, respectively. Chemotype classification of A. flavus isolates based on the ability for producing mycotoxins and sclerotia showed that 43.4 % were producers of CPA, AFB 1 and sclerotia (group I), 13.2 % of CPA and AFB 1 (group II), 9.4 % of AFB 1 and sclerotia (group III), 13.2 % of AFB 1 (group IV), 5.7 % of CPA and sclerotia (group V) and 15.1 % were non-toxigenic with no sclerotia (group VI). No strain was found as producer of only CPA or sclerotia. These results indicate different populations of mycotoxigenic A. flavus strains enable to produce hazardous amounts of AFB 1 and CPA are present in peanuts field soils which can be quite important regard to their potential to contaminate peanuts as a main crop consumed in human and animal nutrition.

Diseases of Edible Oilseed Crops

“…These strains are of great concern in food safety as there is a higher probability of aflatoxin contamination in peanuts in Argentina (Barros et al 2005, Nesci et al 2011. Prevalence of such similar strains of A. flavus is also reported from peanut soils in Iran (Amani et al 2012) and India (Raina and Desai 2006). Consequently, aflatoxin contamination of peanuts becomes one of the most important constraints to peanut production in many countries and becomes a crucial factor in restricting the export of peanuts from one country to another (Asis et al 2009, Xie et al 2009.…”

A Survey of Aflatoxin-Producing Aspergillus sp. from Peanut Field Soils in Four Agroecological Zones of China

“…in soils from the major peanut producing regions of China. Although aflatoxigenic Aspergillus strains have been reported from various crops and agricultural commodities, agricultural soil serves as the main reservoir of these fungi all over the world [ 15 , 16 , 17 , 18 ]. In the present study, A. flavus was the dominant species of Aspergillus fungal population in peanut soil of all districts, which was 94.2% of all strains.…”

Secondary Metabolite Dereplication and Phylogenetic Analysis Identify Various Emerging Mycotoxins and Reveal the High Intra-Species Diversity in Aspergillus flavus

“…Most investigations reporting correlations between sclerotium size, mating-type and VCGs with mycotoxin production have involved the aflatoxins because of their toxicity (Novas and Cabral, 2002; Amani et al, 2012; Moore et al, 2013). However, although A. flavus has potential to produce many other toxic secondary metabolites, most of the toxic effects of these secondary metabolites have been ascribed to aflatoxins.…”