Occurrence and toxigenic potential of Aspergillus section Flavi on wheat and sorghum silages in Uruguay

Agustina Del Palacio,Dinorah Pan

doi:10.1080/21501203.2020.1752321

Abstract

ABSTRACT Species belonging to Aspergillus section Flavi occur naturally in crops and can cause food spoilage and/or toxin production. The aim of this study was to determine the occurrence and diversity of the species of Aspergillus section Flavi found in wheat and sorghum at harvest time and during silage storage, and to evaluate the toxigenic potential of the isolates to determine the contamination risk of mycotoxins in grains. Strains from Aspergillus flavus and Aspergillus parasiticus were found based on multi-gene phylogenetic analyses. This is the first report on the presence of A. parasiticus in wheat from Uruguay. Of the 80 isolates Aspergillus section Flavi, 30% produced aflatoxins (AFs), mainly type B1, and 25% produced cyclopiazonic acid (CPA). Within the isolates from wheat samples, 35% were AFs producers and 27.5% were CPA producers. Among the Aspergillus section Flavi isolates from sorghum, 25% were AFs producers while 22.5% were CPA producers. This work contributes to the knowledge of the species in crops and helps define appropriate strategies for the prevention and control of contamination with AFs and CPA by Aspergillus section Flavi fungi.

Highlights

Wheat is one of the most widely grown crops in the world and is extensively used for human consumption due to its high nutritional value (Hawkesford et al 2013)
And due to the little information in Uruguay about contamination with species that produce aflatoxin in wheat and sorghum silages, the aim of this study was to: i) determine the occurrence and diversity of the species of Aspergillus section Flavi present in wheat and sorghum silages and ii) evaluate the toxigenic potential of the isolates in order to determine the risk of contamination with mycotoxins in these grains and in this kind of storage
Most of the studies about Aspergillus section Flavi are focused on corn silages (Alonso et al 2013) and in a minor extent on wheat and sorghum silages (Del Palacio et al 2016a, 2016b; Divakara et al 2014; Keller et al 2012; Riba et al 2010; Yuan et al 2018)

Summary

Introduction

Wheat is one of the most widely grown crops in the world and is extensively used for human consumption due to its high nutritional value (Hawkesford et al 2013). It is one of the most important cultivated cereals in Uruguay for human consumption, when harvest yield is low it is usual to be ensiled for animal feeding (OPYPA 2018). Since 2015 in Uruguay sorghum has been used to produce bioethanol as well as its sub-product, dried distillers grains with soluble (DDGS), is used for animal feeding (Methol 2018). There may be a decrease in livestock performance (Ferrero et al 2019)

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