Fusarium Mycotoxins Enniatins: An Updated Review of Their Occurrence, the Producing Fusarium Species, and the Abiotic Determinants of Their Accumulation in Crop Harvests

Abstract

Cereal grains and their processed food products are frequently contaminated with mycotoxins produced by the Fusarium genus. Enniatins (ENNs), which belong to the so-called "emerging mycotoxins" family, are among the most frequently found in small grain cereals. Health hazards induced by a chronic exposure to ENNs or an association of ENNs with other major mycotoxins is a risk that cannot be excluded given the current toxicological data. Thus, efforts must be pursued to define efficient control strategies to mitigate their presence in cereal grains. A key condition for achieving this aim is to gain deep and comprehensive knowledge of the factors promoting the appearance of ENNs in crop harvests. After an update of ENN occurrence data, this review surveys the scientific literature on the Fusarium species responsible for ENN contamination and covers the recent advances concerning the abiotic determinants and the genetic regulation of ENN biosynthesis.

Determination of Fungi and Multi-Class Mycotoxins in Camelia sinensis and Herbal Teas and Dietary Exposure Assessment

“…Enniatins (ENNs) and beauvericin (BEA) are emerging Fusarium mycotoxins frequently found in grain products; these mycotoxins raise potential concerns due to their chronic toxicity upon long-term exposure [ 42 , 43 ]. BEA was not observed in any of the analysed 166 tea samples.…”

Investigating the Efficiency of Hydroxycinnamic Acids to Inhibit the Production of Enniatins by Fusarium avenaceum and Modulate the Expression of Enniatins Biosynthetic Genes

“…According to the increasing evidence of the worldwide and frequent occurrence of crop contamination with ENNs, together with the potential risk of health hazards associated with chronic exposure and the likelihood of synergistic toxic effects when ENNs co-occur with other regulated mycotoxins, ENNs might pose a major threat to human and animal health [9]. Efforts should be pursued to define efficient control strategies to mitigate their presence in cereal harvests.…”

“…The most prevalent toxins among the so-called emerging mycotoxins are ENNs [7], which can be found in a wide range of substrates, including potato, apple, sugar beet, coffee beans, and cereal grains, with cereals being the most commonly contaminated agricultural commodities [8]. The map of ENNs occurrence in European cereal harvests, recently drawn by Gautier et al [9], clearly illustrates the high frequency of ENNs contamination events together with the high values of contamination levels that can exceed 500 mg kg −1 for certain crops and countries.…”

“…Among these 29 variants, ENNs A, A 1 , B and B 1 are the most frequently detected in cereal grains; their chemical structures are reported in Figure 1. Nearly 30 fungal species have been shown to have the capacity to yield ENNs, with Fusarium avenaceum and Fusarium tricinctum being the major contributors to the contamination of cereal grains [9]. While the chemical pathway of ENN biosynthesis has been well documented [11], its genetic basis is less known.…”

“…While the chemical pathway of ENN biosynthesis has been well documented [11], its genetic basis is less known. In addition to esyn1 encoding the enniatin synthetase, a non-ribosomal peptide synthetase, that plays a primary role in the biosynthetic pathway of ENNs, only one other gene, kivr, that encodes a ketoisovalerate reductase, has been related to ENNs biosynthesis [9]. Notwithstanding the high prevalence of ENNs in food and feed products, sometimes even in high concentrations, there are still significant knowledge gaps regarding their toxicity.…”