Mycotoxins presence in pre- and post-fermented silage from Tunisia

Maize-fusarium interactions: Tunisian insights into mycotoxin ecology

Maize is a worldwide crop yet can be associated with mycotoxigenic fungi, much investigated in humid tropical and cooler, wet temperate regions. However, in hot, arid/semi-arid regions data on their occurrence are poor. In this paper, we focused on interactions between maize and Fusarium fungal species in Tunisia, which has a Mediterranean climate, with hot, dry summers and milder, damper winters. Maize kernels, stalks, and roots were sampled from 19 agricultural fields and 56, 72, and 88 % of samples, respectively, yielded Fusarium isolates. Based on molecular identifications, these were mainly F. verticillioides (67 %), and other species of Fusarium fujikuroi species complex and members of Fusarium incarnatum-equiseti-, oxysporum-, burgessii-, solani- and concolor species complexes. In addition, five isolates were identified as Clonostachys rosea. Fusarium verticilloides and Fusarium proliferatum, that produce fumonisins, suspected carcinogenic compounds, were isolated from all kinds of samples, whereas the other species were isolated only from root and stems. Fumonisin B1 was higher in kernels than in silage, while deoxynivalenol, potent protein synthesis inhibiting compound, was detected (at low levels) in grains and silage. A subset of selected strains, representative of all species identified, was also used to evaluate their ability to produce mycotoxins.Fusarium verticillioides, Fusariumproliferatum and Fusarium nygamai produced high levels of fumonisin B1in vitro, as well as beauvericin and enniatins. These findings confirm that, even in hot arid regions, which generally do not favour fungal growth, mycotoxin-producing fungi can be reason of concern for human and animal health.

Beauvericin and enniatin B mycotoxins alter aquatic ecosystems: Effects on green algae

Myxotoxins can contaminate algal-based products and arrive to the food chain to consumers producing chronic toxicity effects. Here, we studied phytotoxicity of mycotoxins, beauvericin (BEA) and ennaitin B (ENN B) in four phytoplankton strains: Acutodesmus sp., Chlamydomonas reinhardtii, Haematococcus pluvialis, and Monoraphidium griffithii, which are all green algae. It was tested the capacity of clearing the media of BEA and ENN B at different concentrations by comparing nominal and measured quantifications. Results revealed that Acutodesmus sp. and C. reinhardtii tended to flow up and down growth rate without reaching values below 50% or 60%, respectively. On the other hand, for H. pluvialis and M. griffith, IC50 values were reached. Regarding the clearance of media, in individual treatment a decrease of the quantified mycotoxin between nominal and measured values was observed; while in binary treatment, differences among both values were higher and more noted for BEA than for ENN B.

Mycotoxin contamination in the Arab world: Highlighting the main knowledge gaps and the current legislation

Since the discovery of aflatoxins in the 1960s, knowledge in the mycotoxin research field has increased dramatically. Hundreds of review articles have been published summarizing many different aspects, including mycotoxin contamination per country or region. However, mycotoxin contamination in the Arab world, which includes 22 countries in Africa and Asia, has not yet been specifically reviewed. To this end, the contamination of mycotoxins in the Arab world was reviewed not only to profile the pervasiveness of the problem in this region but also to identify the main knowledge gaps imperiling the safety of food and feed in the future. To the best of our knowledge, 306 (non-)indexed publications in English, Arabic, or French were published from 1977 to 2021, focusing on the natural occurrence of mycotoxins in matrices of 14 different categories. Characteristic factors (e.g., detected mycotoxins, concentrations, and detection methods) were extracted, processed, and visualized. The main results are summarized as follows: (i) research on mycotoxin contamination has increased over the years. However, the accumulated data on their occurrences are scarce to non-existent in some countries; (ii) the state-of-the-art technologies on mycotoxin detection are not broadly implemented neither are contemporary multi-mycotoxin detection strategies, thus showing a need for capacity-building initiatives; and (iii) mycotoxin profiles differ among food and feed categories, as well as between human biofluids. Furthermore, the present work highlights contemporary legislation in the Arab countries and provides future perspectives to mitigate mycotoxins, enhance food and feed safety, and protect the consumer public. Concluding, research initiatives to boost mycotoxin research among Arab countries are strongly recommended.

A comparative review on methods of detection and quantification of mycotoxins in solid food and feed: a focus on cereals and nuts

Many emerging factors and circumstances urge the need to develop and optimize the detection and quantification techniques of mycotoxins in solid food and feed. The diversity of mycotoxins, which have different properties and affinities, makes the standardization of the analytical procedures and the adoption of a single protocol that covers the attributes of all mycotoxins a tedious or even an impossible mission. Several modifications and improvements have been undergone in order to optimize the performance of these methods including the extraction solvents, the extraction methods, the clean-up procedures, and the analytical techniques. The techniques range from the rapid screening methods, which lack sensitivity and specificity such as TLC, to a spectrum of more advanced protocols, namely, ELISA, HPLC, and GC-MS and LC-MS/MS. This review aims at assessing the current studies related to these analytical techniques of mycotoxins in solid food and feed. It discusses and evaluates, through a critical approach, various sample treatment techniques, and provides an in-depth examination of different mycotoxin detection methods. Furthermore, it includes a comparison of their actual accuracy and a thorough analysis of the observed benefits and drawbacks.

Impact of Enniatin and Deoxynivalenol Co-Occurrence on Plant, Microbial, Insect, Animal and Human Systems: Current Knowledge and Future Perspectives

Fusarium mycotoxins commonly contaminate agricultural products resulting in a serious threat to both animal and human health. The co-occurrence of different mycotoxins in the same cereal field is very common, so the risks as well as the functional and ecological effects of mycotoxins cannot always be predicted by focusing only on the effect of the single contaminants. Enniatins (ENNs) are among the most frequently detected emerging mycotoxins, while deoxynivalenol (DON) is probably the most common contaminant of cereal grains worldwide. The purpose of this review is to provide an overview of the simultaneous exposure to these mycotoxins, with emphasis on the combined effects in multiple organisms. Our literature analysis shows that just a few studies on ENN-DON toxicity are available, suggesting the complexity of mycotoxin interactions, which include synergistic, antagonistic, and additive effects. Both ENNs and DON modulate drug efflux transporters, therefore this specific ability deserves to be explored to better understand their complex biological role. Additionally, future studies should investigate the interaction mechanisms of mycotoxin co-occurrence on different model organisms, using concentrations closer to real exposures.

Use of polypyrrole ferrite microparticles and liquid chromatography-mass spectrometry for testing natural grass contamination by multiclass mycotoxins

An analytical methodology based on the combination of dispersive magnetic solid-phase extraction (DMSPE) and liquid chromatography-mass spectrometry (LC-MS) is proposed to explore the occurrence of 13 mycotoxins (aflatoxins B₁, G₁, B₂, and G₂; deoxynivalenol; T-2 toxin; ochratoxin A; HT-2 toxin; enniatins A, A₁, B, and B₂; and beauvericin) and their derivatives in natural grass samples. Magnetic microparticles (Fe₃O₄) coated with polypyrrole (PPy) polymer were used in DMSPE sample treatment as adsorbent phase, and Fourier-transform infrared spectroscopy, field emission scanning electron microscopy, and energy dispersive X-ray spectroscopy have been used for its characterization. The experimental parameters influencing the adsorption and desorption steps of DMSPE have been optimized. Method validation has been carried out obtaining limits of quantification between 0.07 and 92 μg kg^-1 corresponding to enniatin B or A₁ and DON, respectively. A total of 83 natural grass samples from 8 dehesa farms were analysed. Enniatin B was found in all the samples (0.29 to 488 μg kg^-1 concentration range) followed by enniatin B₁ (92.8% of the samples) with a 0.12-137 μg kg^-1 concentration range. Moreover, co-occurrence of mycotoxins was studied and between 2 and 5 mycotoxins appeared simultaneously in 97.6% of the samples. Distribution of the contamination according to natural grass location was also investigated.

Prevalence and Concentration of Mycotoxins in Animal Feed in the Middle East and North Africa (MENA): A Systematic Review and Meta-Analysis

This study seeks a comprehensive meta-analysis of mycotoxin contaminants in animal feed consumed in the Middle East and North Africa (MENA) region. The obtained articles were reviewed, and 49 articles that investigated the contamination of mycotoxins including aflatoxins (AFs), deoxynivalenol (DON), zearalenone (ZEA), T-2 toxin, fumonisins (FUM), and ochratoxin A (OTA), in feed samples or components of animal feed in the MENA region were selected. The titles of the final articles included in the study were meta-analyzed. Necessary information was extracted and categorized from the articles, and a meta-analysis was performed using Stata software. The highest contamination was in dry bread (80%), and Algeria was the most contaminated country (87% of animal feed), with the most mycotoxins contaminating AFs (47%) and FUM (47%). The highest concentration of mycotoxins in animal feed is related to FUM (1240.01 μg/kg). Climate change, economic situation, agricultural and processing methods, the nature of the animal feed, and improper use of food waste in animal feed are among the most critical factors that are effective in the occurrence of mycotoxin contamination in animal feed in MENA. Control of influential factors in the occurrence of contaminations and rapid screening with accurate identification methods to prevent the occurrence and spread of mycotoxin contamination of animal feed seem important.

Ergosterol and polyphenol contents as rapid indicators of orchardgrass silage safety

The ergosterol (ERG) has been proposed as a potential indicator of fungal contamination, along with polyphenol content analysis to predict silage safety. Despite efforts in controlling fungal growth in silage, mycotoxin co-contamination represents a possible risk for animal and human health. Modern analytical techniques determine a multitude of fungal metabolites contaminating feed. Nonetheless, these methods require sometimes arduous sample pre-treatment, long separation times, and expensive standard compounds to identified contaminants. Thus, the goal of this study was to suggest a rapid analysis of ERG and polyphenol contents to assess silage hygienic quality in ten orchardgrass varieties ensiled without and with biological and chemical additives. The determination of ERG on samples was performed by high-performance liquid chromatography using UV detection and UV/Vis spectrophotometry to determine the polyphenol content. Statistically significant differences (P < 0.05) between varieties, years and silage additives were found. Bepro was the unique variety that did not present ERG in the first cut in 2012. ERG content increased in the first cut in 2013 using biological additives as well as ERG and polyphenol contents in the first cut in 2013 using chemical additives compared with untreated silage. In addition, biological and chemical additives used in this study did not satisfactorily reduce the content of ERG and polyphenols in silage grass. Consequently, our results provide fast information about the progressive fungal contamination of grass silage. To our knowledge, it is the first time that the presence of ERG and polyphenols is determined in ten different orchardgrass varieties treated without and with additives. In general, ERG and polyphenol contents showed to be good indicators of orchardgrass silage safety.

Alterations in Daphnia magna exposed to enniatin B and beauvericin provide additional value as environmental indicators

Mycotoxins beauvericin (BEA) and enniatin B (ENN B) affect negatively several systems and demand more studies as the mechanisms are still unclear. The simultaneous presence of contaminants in the environment manifests consequences of exposure for both animals and flora. Daphnia magna is considered an ideal invertebrate to detect effects of toxic compounds and environmental alterations. In this study, the potential toxicity and the basic mechanism of BEA and ENN B individually and combined were studied in D. magna. Acute and delayed toxicity were evaluated, and transcript levels of genes involved in xenobiotic metabolism (mox, gst, abcb1, and abcc5), reproduction, and oxidative stress (vtg-SOD) were analyzed by qPCR. Though no acute toxicity was found, results revealed a spinning around and circular profile of swimming, a strong decrease of survival after 72 h for BEA and ENN B at 16 µM and 6.25 µM, respectively, while for BEA + ENN B [8 + 1.6] µM after 96 h. The amount of mycotoxin remaining in the media revealed that the higher the concentration assayed the higher the amount remaining in the media. Differential regulation of genes suggests that xenobiotic metabolism is affected denoting different effects on transcription for tested mycotoxins. The results provide new insights into the underlying risk assessment of BEA and ENN B not only through food for consumers but also for the environment.

Microbial community and fermentation characteristic of whole-crop wheat silage treated by lactic acid bacteria and Artemisia argyi during ensiling and aerobic exposure

Whole-crop wheat silage (WCWS) is an excellent feed material for ruminants. However, microbial fermentation during silage production consumes valuable nutrients, decreasing the quality of silage. The main objective of this study was to assess how the addition of increasing amounts of Artemisia argyi (AA) affected fermentation quality, microbial composition, and mycotoxin production in whole-crop wheat at dough stage (WCWD) silage during ensiling to aerobic exposure compared with Lactiplantibacillus buchneri (LB). The addition of 20% AA, resulted in a lower pH and higher lactic acid content, was found in silage treated with 20% AA, and an obvious increase in the relative abundance of Lactobacillus was detected in silages treated with LB and 20% AA, respectively. Meanwhile, inoculation with 20% AA decreased the abundance of harmful microorganisms, including Acinetobacter, Enterobacter, and Aspergillus. It also reduced the contents of mycotoxins, Aflatoxin B1 (AFB1), and deoxynivalenol (DON) during ensiling and aerobic exposure. These results confirmed that WCWD treated with 20% AA could improve the fermentation quality and enhance the aerobic stability of silage.

Factors during Production of Cereal-Derived Feed That Influence Mycotoxin Contents

Mycotoxins are naturally present in cereal-based feed materials; however, due to adverse effects on animal health, their presence in derived animal feed should be minimized. A systematic literature search was conducted to obtain an overview of all factors from harvest onwards influencing the presence and concentration of mycotoxins in cereal-based feeds. The feed production processes covered included the harvest time, post-harvest practices (drying, cleaning, storage), and processing (milling, mixing with mycotoxin binders, extrusion cooking, ensiling). Delayed harvest supports the production of multiple mycotoxins. The way feed materials are dried after harvest influences the concentration of mycotoxins therein. Applying fungicides on the feed materials after harvest as well as cleaning and sorting can lower the concentration of mycotoxins. During milling, mycotoxins might be redistributed in cereal feed materials and fractions thereof. It is important to know which parts of the cereals are used for feed production and whether or not mycotoxins predominantly accumulate in these fractions. For feed production, mostly the milling fractions with outer parts of cereals, such as bran and shorts, are used, in which mycotoxins concentrate during processing. Wet-milling of grains can lower the mycotoxin content in these parts of the grain. However, this is typically accompanied by translocation of mycotoxins to the liquid fractions, which might be added to by-products used as feed. Mycotoxin binders can be added during mixing of feed materials. Although binders do not remove mycotoxins from the feed, the mycotoxins become less bioavailable to the animal and, in the case of food-producing animals, to the consumer, lowering the adverse effects of mycotoxins. The effect of extruding cereal feed materials is dependent on several factors, but in principle, mycotoxin contents are decreased after extrusion cooking. The results on ensiling are not uniform; however, most of the data show that mycotoxin production is supported during ensiling when oxygen can enter this process. Overall, the results of the literature review suggest that factors preventing mycotoxin production have greater impact than factors lowering the mycotoxin contents already present in feed materials.

In silico methods for metabolomic and toxicity prediction of zearalenone, α-zearalenone and β-zearalenone

Zearalenone (ZEA), α-zearalenol (α-ZEL) and β-zearalenol (β-ZEL) (ZEA's metabolites) are co/present in cereals, fruits or their products. All three with other compounds, constitute a cocktail-mixture that consumers (and also animals) are exposed and never entirely evaluated, nor in vitro nor in vivo. Effect of ZEA has been correlated to endocrine disruptor alterations as well as its metabolites (α-ZEL and β-ZEL); however, toxic effects associated to metabolites generated once ingested are unknown and difficult to study. The present study defines the metabolomics profile of all three mycotoxins (ZEA, α-ZEL and β-ZEL) and explores the prediction of their toxic effects proposing an in silico workflow by using three programs of predictions: MetaTox, SwissADME and PASS online. Metabolomic profile was also defined and toxic effect evaluated for all metabolite products from Phase I and II reaction (a total of 15 compounds). Results revealed that products describing metabolomics profile were: from O-glucuronidation (1z and 2z for ZEA and 1 ab, 2 ab and 3 ab for ZEA's metabolites), S-sulfation (3z and 4z for ZEA and 4 ab, 5 ab and 6 ab for ZEA's metabolites) and hydrolysis (5z and 7 ab for ZEA's metabolites, respectively). Lipinsky's rule-of-five was followed by all compounds except those coming from O-glucuronidation (HBA>10). Metabolite products had better properties to reach blood brain barrier than initial mycotoxins. According to Pa values (probability of activation) order of toxic effects studied was carcinogenicity > nephrotoxic > hepatotoxic > endocrine disruptor > mutagenic (AMES TEST) > genotoxic. Prediction of inhibition, induction and substrate function on different isoforms of Cytochrome P450 (CYP1A1, CYP1A2, CYP2C9 and CYP3A4) varied for each compounds analyzed; similarly, for activation of caspases 3 and 8. Relying to our findings, the metabolomics profile of ZEA, α-ZEL and β-ZEL analyzed by in silico programs predicts alteration of systems/pathways/mechanisms that ends up causing several toxic effects, giving an excellent sight and direct studies before starting in vitro or in vivo assays contributing to 3Rs principle; however, confirmation can be only demonstrated by performing those assays.

Reducing the effect of beauvericin on neuroblastoma SH-SY5Y cell line by natural products

In the present work, different natural compounds from coffee by-product extracts (coffee silverskin and spent coffee) rich in polyphenols, was investigated against beauvericin (BEA) induced-cytotoxicity on SH-SY5Y cells. Spent coffee arise as waste products through the production of instant coffee and coffee brewing; while the silverskin is a tegument which is removed and eliminated with toasting coffee grains. First of all, polyphenol extraction methods, measurement of total polyphenols content and its identification were carried out. Afterwards evaluating in vitro effects with MTT assay on SH-SY5Y cells of coffee by-product extracts and mycotoxins at different concentrations and exposure times was performed. TPC in silverskin coffee by-product extracts was >10 times higher than in spent coffee by-product extracts. Chlorogenic acid was the majority polyphenol detected. Viability for BEA reached IC₅₀ values at 72h (2.5 μM); boiling water silverskin coffee extract reached the highest viability also in pre-treatment BEA exposure and compared with MeOH and MeOH:H₂O (v/v, 50:50) extracts. These results in SH-SY5Y cells highlight the use of such residues as supplements or bioactive compounds in the future.