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Potential economic losses to the USA corn industry from aflatoxin contamination
Abstract
Mycotoxins, toxins produced by fungi that colonise food crops, can pose a heavy economic burden to the United States corn industry. In terms of economic burden, aflatoxins are the most problematic mycotoxins in US agriculture. Estimates of their market impacts are important in determining the benefits of implementing mitigation strategies within the US corn industry, and the value of strategies to mitigate mycotoxin problems. Additionally, climate change may cause increases in aflatoxin contamination in corn, greatly affecting the economy of the US Midwest and all sectors in the US and worldwide that rely upon its corn production. We propose two separate models for estimating the potential market loss to the corn industry from aflatoxin contamination, in the case of potential near-future climate scenarios (based on aflatoxin levels in Midwest corn in warm summers in the last decade). One model uses probability of acceptance based on operating characteristic (OC) curves for aflatoxin sampling and testing, while the other employs partial equilibrium economic analysis, assuming no Type 1 or Type 2 errors, to estimate losses due to proportions of lots above the US Food and Drug Administration (FDA) aflatoxin action levels. We estimate that aflatoxin contamination could cause losses to the corn industry ranging from $52.1 million to $1.68 billion annually in the United States, if climate change causes more regular aflatoxin contamination in the Corn Belt as was experienced in years such as 2012. The wide range represents the natural variability in aflatoxin contamination from year to year in US corn, with higher losses representative of warmer years.
... Corn is susceptible to AFL toxigenic strains, which pose a significant health, economic, and safety risk to humans and livestock when they consume contaminated products (Munkvold et al., 2019). The economic impact of AFL has been estimated to be between $418 million to $1.66 billion for all stakeholders in the US agricultural industry and can infiltrate the supply chain in corn-based commodities (Wu, 2006;Mitchell et al., 2016). AFL is primarily produced from the fungal strains Aspergillus flavus and A. parasiticus via the polyketide pathway (Sweeney and Dobson, 1998). ...
... Temperature and rainfall conditions in the principal corn-growing states in the US are typically sufficient to slow the growth of A. flavus and parasiticus, avoiding significant AFL accumulation (Munkvold, 2014). However, in drought and high-temperature years, AFL contamination has been documented in Iowa (Lillehoj et al., 1976;Schmitt and Hurburgh, 1989;Mitchell et al., 2016). These AFL challenges exist in the Corn Belt region of the US; climate change patterns with temperature increases will likely increase the AFL concentration in corn in the US (Wu et al., 2011;Yu et al., 2022). ...
... For grain elevators, handlers, and processors, prediction models enable proactive planning for handling, storing, and marketing grain with differing risk levels and facilitates strategic sampling and testing (Fumagalli et al., 2021). These machinelearning models can guide rapid decision-making and diversion necessary before the point of first receipt at the elevator to improve the overall safety and profitability of the US corn supply without compromising the profitability of individual grain businesses (Mitchell et al., 2016;Castano-Duque et al., 2022). ...
Introduction: Aflatoxin (AFL), a secondary metabolite produced from filamentous fungi, contaminates corn, posing significant health and safety hazards for humans and livestock through toxigenic and carcinogenic effects. Corn is widely used as an essential commodity for food, feed, fuel, and export markets; therefore, AFL mitigation is necessary to ensure food and feed safety within the United States (US) and elsewhere in the world. In this case study, an Iowa-centric model was developed to predict AFL contamination using historical corn contamination, meteorological, satellite, and soil property data in the largest corn-producing state in the US.
Methods: We evaluated the performance of AFL prediction with gradient boosting machine (GBM) learning and feature engineering in Iowa corn for two AFL risk thresholds for high contamination events: 20-ppb and 5-ppb. A 90%–10% training-to-testing ratio was utilized in 2010, 2011, 2012, and 2021 (n = 630), with independent validation using the year 2020 (n = 376).
Results: The GBM model had an overall accuracy of 96.77% for AFL with a balanced accuracy of 50.00% for a 20-ppb risk threshold, whereas GBM had an overall accuracy of 90.32% with a balanced accuracy of 64.88% for a 5-ppb threshold. The GBM model had a low power to detect high AFL contamination events, resulting in a low sensitivity rate. Analyses for AFL showed satellite-acquired vegetative index during August significantly improved the prediction of corn contamination at the end of the growing season for both risk thresholds. Prediction of high AFL contamination levels was linked to aflatoxin risk indices (ARI) in May. However, ARI in July was an influential factor for the 5-ppb threshold but not for the 20-ppb threshold. Similarly, latitude was an influential factor for the 20-ppb threshold but not the 5-ppb threshold. Furthermore, soil-saturated hydraulic conductivity (Ksat) influenced both risk thresholds.
Discussion: Developing these AFL prediction models is practical and implementable in commodity grain handling environments to achieve the goal of preventative rather than reactive mitigations. Finding predictors that influence AFL risk annually is an important cost-effective risk tool and, therefore, is a high priority to ensure hazard management and optimal grain utilization to maximize the utility of the nation’s corn crop.
... Among the mycotoxins, AFs are considered the most toxic, with a significant economic burden to agriculture [4,5]. Favourable conditions for growth of AFs include high moisture content and high temperature. ...
... AFs can contaminate agricultural commodities including corn, wheat, rice, peanut, and many other crops [6,7]. AFs are primarily an economic concern in the United States and European Union countries, whereas in the developing countries of Asia and Africa, AFs contribute to hundreds of hepatocellular carcinoma cases each year [4,8,9]. The total estimated annual losses to the US corn industry is from US $52.1 million to US $1.68 billion due to aflatoxin contamination [4]. ...
... AFs are primarily an economic concern in the United States and European Union countries, whereas in the developing countries of Asia and Africa, AFs contribute to hundreds of hepatocellular carcinoma cases each year [4,8,9]. The total estimated annual losses to the US corn industry is from US $52.1 million to US $1.68 billion due to aflatoxin contamination [4]. ...
The mold Aspergillus grows on several raw food commodities and produces highly toxic compounds known as aflatoxins. These compounds can cause developmental and immune system suppression, cancer, and death if ingested. The aim of this study was to determine the aflatoxin levels in various crops obtained from farms in South Carolina, USA. Aflatoxin levels were measured using the Vicam Virtu Reader and High-Performance Liquid Chromatography (HPLC). The Vicam Virtu Reader utilized five grams of corn and peanuts blended and placed into an extraction tube containing 25 ml of 70% methanol. The sample mixture was placed on the AlfaV test strip for readings. For use of the HPLC, the samples were analyzed by isocratic using 60:20:20 water/methanol/acetonitrile mixture as the mobile phase. Results from the Vicam Virtu Reader indicated corn samples and peanut samples had aflatoxin levels below 25 ppb established by the USDA. When the HPLC analysis was done on soybean, wheat, and cottonseed, all results were below 25 ppb as well. A food safety survey was administered to 190 farmers to ascertain their familiarity with aflatoxins. Sixteen percent (16%) reported they heard about it. In conclusion, storage conditions of the crops can affect the level of aflatoxins. The Vicam Virtu Reader is a fast method to identify aflatoxin levels in crops. The HPLC has the advantage of separating aflatoxins into subgroups even at low levels. The aflatoxin levels were low and safe for export and consumption.
... Abiotic stressors such as drought significantly increase AF contamination in maize (Kebede et al., 2012;Fountain et al., 2014). Computer model-based prediction projects that alterations in environmental conditions due to climate change could lead to a significant increase in AF contamination in maize resulting in an estimated annual loss of $50 million to $1.7 billion to the US maize industry (Mitchell et al., 2016). In 2013, economic losses in the US resulting from A. flavus alone in maize were estimated to be $686.6 million (Mitchell et al., 2016). ...
... Computer model-based prediction projects that alterations in environmental conditions due to climate change could lead to a significant increase in AF contamination in maize resulting in an estimated annual loss of $50 million to $1.7 billion to the US maize industry (Mitchell et al., 2016). In 2013, economic losses in the US resulting from A. flavus alone in maize were estimated to be $686.6 million (Mitchell et al., 2016). Total costs attributable to AF contamination are much higher when factors such as sampling and testing, destruction and disposal, and human and animal health effects are accounted for. ...
Aflatoxin (AF) contamination, caused by Aspergillus flavus , compromises the food safety and marketability of commodities, such as maize, cotton, peanuts, and tree nuts. Multigenic inheritance of AF resistance impedes conventional introgression of resistance traits into high-yielding commercial maize varieties. Several AF resistance-associated quantitative trait loci (QTLs) and markers have been reported from multiple biparental mapping and genome-wide association studies (GWAS) in maize. However, QTLs with large confidence intervals (CI) explaining inconsistent phenotypic variance limit their use in marker-assisted selection. Meta-analysis of published QTLs can identify significant meta-QTLs (MQTLs) with a narrower CI for reliable identification of genes and linked markers for AF resistance. Using 276 out of 356 reported QTLs controlling resistance to A. flavus infection and AF contamination in maize, we identified 58 MQTLs on all 10 chromosomes with a 66.5% reduction in the average CI. Similarly, a meta-analysis of maize genes differentially expressed in response to (a)biotic stresses from the to-date published literature identified 591 genes putatively responding to only A. flavus infection, of which 14 were significantly differentially expressed (−1.0 ≤ Log2Fc ≥ 1.0; p ≤ 0.05). Eight MQTLs were validated by their colocalization with 14 A. flavus resistance-associated SNPs identified from GWAS in maize. A total of 15 genes were physically close between the MQTL intervals and SNPs. Assessment of 12 MQTL-linked SSR markers identified three markers that could discriminate 14 and eight cultivars with resistance and susceptible responses, respectively. A comprehensive meta-analysis of QTLs and differentially expressed genes led to the identification of genes and makers for their potential application in marker-assisted breeding of A. flavus -resistant maize varieties.
... Phenolic and dehydrodiferulic acid are secondary metabolic compounds and act as natural defense molecules against ECB and other insect pests (Miedaner and Juroszek 2021). Tolerance or resistance refers to the plant's ability to grow, reproduce, withstand the attack of insects, repair injury to a certain extent, and reduce the damages to crop yield without affecting the economic loss by the grain yield or quality (Mitchell et al. 2016). In the vegetative stages of growth, 90% of 400 maize hybrids in the market have exhibited some level of resistance. ...
... GER reduces the yield and quality of kernels and triggers the accumulation of mycotoxins (vomitoxin and zearalenone) which cause serious health problems in humans and animals (Brauner et al. 2017 (Woloshuk and Wise 2011). Aflatoxin contamination of maize is a major problem in the southern parts of the United States (Mitchell et al. 2016). Symptoms of AER include green to yellowish fungal growth on and between grains near the ear tip mostly (Woloshuk and Wise 2011). 5. Fusarium ear rot (FER): This maize disease is prevalent worldwide affecting grain yield and quality that is caused by fungus Fusarium verticillioides . ...
Maize being versatile crop is known for its many uses. It has substantially contribution to food security in the poor country. In the recent past, deliberate attempts have been made to integrate trait-based genomic approaches to complement conventional plant breeding. However, the success of the genomics mainly based on phenotypic expression of a trait, hence phenotyping, is one of the key components of plant breeding including maize. Genetic dissection of key traits and its molecular mechanism involves extensive phenotyping of large set of population. Screening of such a huge population is with traditional methods, which is expensive and tedious and consumes a lot of time. In addition, plant phenotypes are the results of interaction between genotype × environment × management (G × E × M); thus, they are complex in nature. Recent developments in phenomics led to the improvement in phenotyping protocol that is more powerful than ever to dissect complex traits into easily scorable traits. In addition, this helps in uncovering underlying genetic mechanism for trait expression. This chapter aimed at describing phenotyping tools available for plant scientist to fast track their maize improvement in precise and robust manner for climate resilient agriculture.
... Among the most impacted of crops is maize, which is grown worldwide and is susceptible to A. flavus infection, especially during seasonal high temperatures and reduced water availability [2]. It has been reported that maize crop losses due to AF contamination in the U.S alone have reached USD 686.6 million per year [3]. Potential changes in climate conditions could exacerbate the impact of aflatoxins in maize with some estimates as high as USD 1.68 billion per year [3]. ...
... It has been reported that maize crop losses due to AF contamination in the U.S alone have reached USD 686.6 million per year [3]. Potential changes in climate conditions could exacerbate the impact of aflatoxins in maize with some estimates as high as USD 1.68 billion per year [3]. ...
Citation: Gilbert, M.K.; Mack, B.M.; Lebar, M.D.; Chang, P.-K.; Gross, S.R.; Sweany, R.R.; Cary, J.W.; Rajasekaran, K. Putative Core Transcription Factors Affecting Virulence in Aspergillus flavus during Infection of Maize. J. Fungi 2023, 9, 118. https:// Abstract: Aspergillus flavus is an opportunistic pathogen responsible for millions of dollars in crop losses annually and negative health impacts on crop consumers globally. A. flavus strains have the potential to produce aflatoxin and other toxic secondary metabolites, which often increase during plant colonization. To mitigate the impacts of this international issue, we employ a range of strategies to directly impact fungal physiology, growth, and development, thus requiring knowledge on the underlying molecular mechanisms driving these processes. Here we utilize RNA-sequencing data that are obtained from in situ assays, whereby Zea mays kernels are inoculated with A. flavus strains, to select transcription factors putatively driving virulence-related gene networks. We demonstrate, through growth, sporulation, oxidative stress-response, and aflatoxin/CPA analysis, that three A. flavus strains with knockout mutations for the putative transcription factors AFLA_089270, AFLA_112760, and AFLA_031450 demonstrate characteristics such as reduced growth capacity and decreased aflatoxin/CPA accumulation in kernels consistent with decreased fungal pathogenicity. Furthermore, AFLA_089270, also known as HacA, eliminates CPA production and impacts the fungus's capacity to respond to highly oxidative conditions, indicating an impact on plant colonization. Taken together, these data provide a sound foundation for elucidating the downstream molecular pathways potentially contributing to fungal virulence.
... In fact, AFs' contamination in food products primarily inflicts economic rather than health burdens in industrial countries, reducing the economic value of crops and causing the disposal of large amounts of food products. For instance, losses to the US corn industry from AFs' contamination could exceed $1 billion during years with warm summers and drought, which are conditions that favor fungi proliferation [16]. Conversely, in low-income countries, the health impacts of AFs are more severe. ...
... The production of valuable products (i.e., biomethane and compost) may help farmers facing economic losses derived from the impossibility of selling their crop to grain elevators, or to shellers or other handlers. In addition to the loss of crops and feeds storage, regulatory and disposal costs, health care and veterinary care costs, loss of livestock production, monitoring and research activities for the determination of mycotoxins, and possible loss of human and animal life have to be involved in the total count of economic losses derived by aflatoxin and mycotoxin contamination [99], making the quantification of economic implications an extremely difficult task [16,100]. ...
Mycotoxins’ contamination of food products is a well-known issue that is gaining interest nowadays due to increasing contaminations that are also related to climate change. In this context, and considering the principles of Circular Economy, finding robust and reliable strategies for the decontamination and valorisation of mycotoxin-contaminated products becomes mandatory. Anaerobic digestion (AD) and composting appear as promising biological treatments to degrade mycotoxins and allow for recovering energy (i.e., biogas production) and materials (i.e., nutrients from digestate and/or compost). The aim of the present paper was to carry out an organic revision of the state of the art of energy and materials recovery from mycotoxin-contaminated food products through biological treatments, highlighting results and research gaps. Both processes considered were not generally affected by the contamination of the feedstocks, proving that these compounds do not affect process stability. Mycotoxins were highly removed due to the concurrence of microbiological and physical agents in AD and composting. From the literature review, emerged the points that still need to be addressed before considering large scale application of these processes, which are (i) to deepen the knowledge of biochemical transformations of mycotoxins during the processes, (ii) to assess the fate of mycotoxins’ residues and metabolites in soil once digestate/compost are applied, (iii) to evaluate and optimize the integration of AD and composting in order to increase the environmental and economical sustainability of the processes, and (iv) to update legislation and regulations to allow the agricultural reuse of organic fertilizers obtained from contaminated feedstocks.
... For example, aflatoxin, a mycotoxin produced primarily by Aspergillus flavus, is highly toxic and a potent naturally occurring carcinogen (Wild and Gong, 2010;Coppock et al., 2018), and contamination levels are predicted to increase due to impending climate change (Battilani et al., 2016). Currently, estimated US losses range from $52.1 million to $1.68 billion annually for aflatoxin alone (Mitchell et al., 2016). Unlike the United States and several developed nations within the European Union, the implementation of the stringent quality control methods for lowering the dietary exposure to mycotoxins is not always feasible. ...
Aflatoxins, a family of fungal secondary metabolites, are toxic and carcinogenic compounds that pose an enormous threat to global food safety and agricultural sustainability. Specifically agricultural products in African, Southeast Asian and hot and humid regions of American countries suffer most damage from aflatoxin producing molds due to the ideal climate conditions promoting their growth. Our recent studies suggest that Vibrio gazogenes (Vg), an estuarine bacterium non-pathogenic to plants and humans, can significantly inhibit aflatoxin biosynthesis in the producers. In this study, we investigated the mechanism underlying Vg-dependent aflatoxin inhibition using the prominent aflatoxin producer, Aspergillus flavus . We show that aflatoxin inhibition upon Vg treatment was associated with fungal uptake of Vg-prodigiosin, a red pigment, which was consistently visible inside fungal hyphae during treatment. The association of prodigiosin with aflatoxin inhibition was further evident as Serratia marcescens , another prodigiosin producer, significantly inhibited aflatoxin, while non-producers like Escherichia coli, Staphylococcus aureus , Vibrio harveyi , and Vibrio fischeri did not. Also, pure prodigiosin significantly inhibited aflatoxin biosynthesis. Endocytosis inhibitors, filipin and natamycin, reduced the Vg-prodigiosin uptake by the fungus leading to a significant increase in aflatoxin production, suggesting that uptake is endocytosis-dependent. The Vg treatment also reduced hyphal fusion (>98% inhibition) and branching, which are both endosome-dependent processes. Our results, therefore, collectively support our theory that Vg-associated aflatoxin inhibition is mediated by an endocytosis-dependent uptake of Vg-prodigiosin, which possibly leads to a disruption of normal endosomal functions.
... The genus Aspergillus contains more than 300 biotechnologically, medically and agriculturally relevant species including the model filamentous fungus Aspergillus nidulans and the opportunistic human pathogen A. fumigatus and the notorious toxin producing species A. flavus which is both a plant and human pathogen (Amaike and Keller, 2009;Hedayati et al., 2007). A. flavus can contaminate oil-rich seeds such as corn, maize or peanuts during pre or post-harvest with the carcinogenic mycotoxin, aflatoxin (AF) (Mitchell et al., 2016). Every year, approximately $1 billion of economic loss is caused by AF contamination in the US alone (Amare and Keller, 2014). ...
The filamentous fungus Aspergillus flavus is a plant and human pathogen predominantly found in the soil as spores or sclerotia and is capable of producing various secondary metabolites (SM) such as the carcinogenic mycotoxin aflatoxin. Recently, we have discovered a novel nuclear chromatin binding complex (KERS) that contains the JARID1-type histone demethylase KdmB, a putative cohesion acetyl transferase EcoA, a class I type histone deacetylase RpdA and the PHD ring finger reader protein SntB in the model filamentous fungus Aspergillus nidulans. Here, we show the presence of the KERS complex in A. flavus by immunoprecipitation-coupled mass spectrometry and constructed kdmBΔ and rpdAΔ strains to study their roles in fungal development, SM production and histone post-translational modifications (HPTMs). We found that KdmB and RpdA couple the regulation of SM gene clusters with fungal light-responses and HPTMs. KdmB and RpdA have opposing roles in light-induced asexual conidiation, while both factors are positive regulators of sclerotia development through the nsdC and nsdD pathway. KdmB and RpdA are essential for the productions of aflatoxin (similar to findings for SntB) as well as cyclopiazonic acid, ditryptophenaline and leporin B through controlling the respective SM biosynthetic gene clusters. We further show that both KdmB and RpdA regulate H3K4me3 and H3K9me3 levels, while RpdA also acts on H3K14ac levels in nuclear extracts. Therefore, the chromatin modifiers KdmB and RpdA of the KERS complex are key regulators for fungal development and SM metabolism in A. flavus.
... Aflatoxin contamination in various feed materials such as corn, maize, sorghum, rice and wheat are common worldwide (1)(2)(3). Aflatoxin contamination of corns cause economic losses in U.S. corn industry between US$52.1 and US$1.68 billion (4). Estimates of the economic losses caused by mycotoxin contamination vary, nevertheless, neither of these estimates contain human health impact of aflatoxin contamination. ...
Cite as: DOGAN. V Negative Effects of aflatoxin B1 on Sperm IJCMBS 2022;2(3):215-18 doi.org/ 10.5281/zenodo.6835093 Abstract Aflatoxins are secondary metabolites that produced by Aspergillus fungi which are soilborne and involved in the decomposition of plant materials in nature. Aspergillus species find opportunity to produce aflatoxins in high humidity and temperature conditions such as tropical and subtropical environment. Therefore, in changing climatic conditions caused by global warming, geographical distribution of these fungi to have changed day by day, and find out an opportunity to grow in different feed materials. Aflatoxin B1 (AFB1) is the most toxigenic mycotoxin in these group and threatens both human and animal health due to its carcinogenic and mutagenic properties. In cattle, commonly known adverse effects of AFB1 depending on the chronic exposure such as decreasing milk production and quality, reducing the feed efficiency in beef cattle, increase susceptibility to diseases following suppression of the immune system, compromise ruminal functions, disruption of ruminal microorganism growth and functions. In this study, the negative effects of AFB1 on bull sperm has been examined. Topics such as negative effects of AFB1 on sperm proteomes, increase in the reactive oxygen species, changes in sperm DNA and plasma membrane integrity are discussed. ÖZ Aflatoksinler, toprak kaynaklı olan ve bitkisel materyallerin çürümesinde görev alan Aspergillus türü mantarlar tarafından üretilen sekonder metabolitlerdir. Aspergillus türleri, tropikal ve subtropikal ortamlar gibi yüksek nem ve sıcaklık koşullarında aflatoksin üretme fırsatı bulmaktadır. Bu nedenle, küresel ısınmanın neden olduğu iklim değişikliklerine bağlı olarak aflatoksin üreten mantarların coğrafi yayılışları değişmekte ve farklı yem materyallerinde üreme imkanı bulmaktadırlar. Aflatoksinler içerisinde en toksik olanı aflatoksin B1'dir (AFB1) ve karsinojenik ve mutajenik özelliğinden dolayı insan ve hayvan sağlığını tehdit etmektedir. Aflatoksin B1'e uzun süre maruz kalmaya bağlı olarak sığırlarda; süt veriminde ve kalitesinde azalma, besi sığırlarında yemden yararlanmada düşme, immun sistemin baskılanması ve buna bağlı olarak hastalıklara karşı duyarlılıkta artış, karaciğer fonksiyonlarının baskılanması, rumen fonksiyonlarında azalma, rumen mikroorganizmalarının gelişme ve fonksiyonlarının sekteye uğratılması gibi etkileri yaygın olarak bilinmektedir. Bu çalışmada, AFB1'in boğa spermi üzerindeki olumsuz etkileri incelenmiştir. Boğa spermindeki proteomlar, reaktif oksijen türlerindeki artışlar ve plazma membran bütünlüğündeki değişiklikler, sperm DNA'sında meydana gelen değişiklikler gibi konular ele alınmıştır. Anahtar Kelime: Aflatoksin, Aflatoksin B1, Sperm DOGAN.V Negative Effects of Aflatoxin B1 on Sperm 216 Highlights • AFB1 impairs the spermatozoa acrosome reaction and capacitation. • AFB1 reduces PARK7 expression in spermatozoa and increases ROS generation. • DNA fragmentation in spermatozoa is increased in males exposed to AFB1.
... However, these regulations have led to substantial annual losses in the agricultural industry. In the United States alone, losses due to aflatoxins, including AFB 1 , have been estimated to range from $52.1 million to $1.68 billion annually (Mitchell et al., 2016). Current strategies for AFB 1 control primarily focus on decontamination by degrading or removing AFB 1 from crops, as well as prevention by implementing appropriate management systems to reduce AFB 1 contamination in the field and during storage (Benkerroum, 2009). ...
Aflatoxin B1 (AFB1), the most potent mycotoxin and Group 1 human carcinogen, continues to pose a significant public health burden, particularly in developing countries. Increasing evidence has shown the gut microbiota as a key mediator of AFB1 toxicity through multiple interactive host-microbiota activities. In our previous study we observed that disturbances in bacterial pyruvate metabolism might have a significant impact on AFB1 in the host. To further investigate the impact of the pyruvate pathway on AFB1 toxicity in C. elegans, we engineered two bacterial strains (triple-overexpressed and triple-knockout strains with aceB, lpd, and pflB). Additionally, we employed two mutant worm strains (pyk-1 and pdha-1 mutants) known to affect pyruvate metabolism. Our results revealed that the co-metabolism of pyruvate by the host and bacterial strains synergistically influences AFB1 toxicity. Remarkable, we found that bacterial pyruvate metabolism, rather than that of the host, plays a pivotal role in modulating AFB1 toxicity in C. elegans. Our study sheds light on the role of gut microbiota involved in pyruvate metabolism in influencing AFB1 toxicity in C. elegans.
... Aflatoxins are mostly processed a reactive epoxide intermediate is produced by the liver, or the less dangerous aflatoxin M1 (37 The primary CYP enzymes involved in the metabolism of human AFB1 in the liver are CYP3A4, CYP3A5, and CYP1A2, whereas lipoxygenases and prostaglandin H synthase appear to be important in its biotransformation in the lung (38,39). There are numerous pathways in AFB1's metabolism, including some of which are shown in figure 3. Additional processes include odealkylation to AFP1, hydroxylation to AFM1 and AFQ1, and ketoreduction to AFL. ...
It has been reported that AFB1 is related to renal adverse effects, specially with Uncertain cause chronic kidney disease. It is a phrase that has been employed to refer to CKD that is not caused by any well-known risk factors, such as hypertension, diabetes, or HIV. Across the world, reports of CKDu are becoming more frequent, and in several areas in Central America, eastern Europe, and south Asia, they are reaching epidemic levels. In the first epidemiological investigation, which was conducted in 2007 and sought to uncover potential risk factors of CKDu, it was claimed that the disease was caused by the environment (1). Environmental factors that have been researched as potential causes of CKDu include heavy metal exposure, high seasonal temperatures, pesticide use, mycotoxins, polluted water resources, and snake bites. In order to comprehend and avoid CKDu, it may be useful to highlight common risk factors across various international settings and populations as the underlying aetiologies in most locations have not been adequately defined. 30% and 21%, respectively, of ESRD patients have diabetes and hypertension; however, younger individuals in underdeveloped nations are more likely to have glomerulonephritis and CKD with an unknown aetiology. As a result, the goal of this research was to follow the theoretical research on AFB1 and its part in the aetiology of chronic renal disease, which is yet unknown.
... For example, discount schedules for aflatoxin are published by most grain elevators, multi-peril crop insurance includes quality indemnification for mycotoxin contamination, and mycotoxin testing accuracy by firms through the adoption of a quality systems approach using USDA approved sampling, grinding, and testing protocol and access to reference material and proficiency testing programs to ensure testing accuracy are available to all, though adopted by few. Economic drivers and past economic loss estimates, while exaggerated [13], appear sufficient to warrant adoption of co-regulation beyond Texas. OTSC is working with developing countries through the Aflatoxin Proficiency Testing and Control in Africa (APTECA) program and collaborations with international organizations including those in Eastern and Southern Africa, the World Food Program, faculty in Kenya, Malawi, and Rwanda and trade associations [26][27][28]. ...
Aflatoxins are toxic fungal metabolites that occur naturally in the field among cereals, oilseeds, and nuts that may increase during storage. Texas grown maize, commonly referred as corn, has some of the highest aflatoxin levels in the US. In 2011, the Office of the Texas State Chemist (OTSC) collaborated with the Risk Management Agency (RMA) of the United States Department of Agriculture (USDA) and the Texas grain industry to implement the state's first co-regulation governance option to manage aflatoxin risk. Co-regulation is a form of risk management that relies upon a government-private partnership in regulation; utilizing government-backed codes of practice that result in a more connected and transparent marketplace. To measure the economic benefit of co-regulation to manage aflatoxin risk, interviews were conducted among twenty-seven participants in the OTSC aflatoxin co-regulation program who represented 31% of the grain companies that handled maize contaminated by aflatoxin according to Texas Commercial Feed Rules. A comparative approach was used by gathering evidence from 2010 to 2018, in order to evaluate the results before and after the OTSC implemented its co-regulation strategy. The results were evaluated by using the data gathered from the interviews to measure the specific costs and benefits incurred by producers and grain handlers. The findings were modeled in the form of an income statement. From the income statement, the total economic benefit of the One Sample Strategy in 2018 was $14,572,180. This study provides a more realistic characterization of cost drivers associated with aflatoxin risk management and counters exaggerated economic losses associated with aflatoxin in maize from prior studies.
... Several researchers have calculated the annual losses caused by AFB 1 contamination in various countries. Estimated losses in the United States have ranged from $20 million to $1.68 billion (Mitchell et al., 2016;Wu et al., 2008). As a result of AFB 1 250 mg/kg, poultry feed intake was reduced by 9-11% across all age groups (Pandey & Chauhan, 2007). ...
Aflatoxin B1 (AFB1 ) is the predominant mycotoxin that originated toxicity in broilers through oxidative damage, intestinal barrier dysfunction, reduced immune system and dysfunction of microorganisms and enzymes in target organs. The intestine is the first AFB1 target organ destroyed after the bird's body is induced. This review summarises the current knowledge of the negative results of AFB1 -induced intestinal damage on broiler production. It was conducted in accordance with the relevant studies in the cited literatures being retrieved from PubMed, Google Scholar, Science Direct and Web of Science. First, AFB1 can change the intestinal barrier function by destroying the intestinal architecture, tissue and cell integrity of the gut epithelium. Second, AFB1 can damage the immune barrier function of the gastrointestinal mucosa. Third, the microbiota of birds interacts closely with the ingested aflatoxin. Finally, because broilers are tremendously sensitive to AFB1 contamination, the poisonous and noxious effects of this mycotoxin in the broiler industry cause millions of dollars in losses every year. This review briefly discussed that the AFB1 , which affects the intestines of broiler chickens, was reduced the immune apparatus, antioxidant protection system, gastric system, and broiler production status and its impact on human health. Therefore, this review will improve our perception of the important intestine in a bird's health and the adverse effect of AFB1 .
... The treatment with 0.2% MA-EO had seriously damaged the cell ultrastructure of the bacterial body, deformed the cell morphology, signi cantly reduced the number of mitochondria, thinned the thickness of the cell wall, changed the color of the intracellular matrix, and formed a large number of vesicles in the plasma membrane to form cavities (Figure 3b). It has been reported that plant essential oils have similar antibacterial properties and morphological changes against other harmful fungi (Li et al., 2013;Mitchell et al., 2016). It can be concluded that the antifungal effect of MA-EO may be partly attributed to the substantial damage of mycelial cell structure and organelles. ...
In the natural environment, Aspergillus flavus often causes contamination of food, crop and Chinese medicinal materials, threatening the quality and safety of food, crop and medicinal materials and causing huge economic losses. In this study, we isolated, identified and screened the strains of A. flavus invading polygalae radix , and determined the changes of growth indexes, virulence, antioxidant system and cell membrane integrity of A. flavus under the treatment of Melaleuca alternifolia essential oil (MA-EO). Combined with the results of proteomics, the mechanism of action was clarified. In addition, this study also measured the change of active components in polygalae radix under the action of MA-EO. The results showed that MA-EO could damage cell membrane integrity, increase ROS accumulation, disrupt antioxidant system and inhibit the growth and toxicity of A. flavus . At the same time, MA-EO can significantly reduce the mildew of polygalae radix and curb the loss of active components after mildew.
... However, these regulations have led to substantial annual losses in the agricultural industry. In the United States alone, losses due to aflatoxins, including AFB 1 , have been estimated to range from $52.1 million to $1.68 billion annually (Mitchell et al., 2016). Current strategies for AFB 1 control primarily focus on decontamination by degrading or removing AFB 1 from crops, as well as prevention by implementing appropriate management systems to reduce AFB 1 contamination in the field and during storage (Benkerroum, 2009). ...
... causing immunosuppression, and damaging DNA, resulting in irreparable damage (6). In the United States, aflatoxin contamination causes annual economic losses of nearly $1.68 billion in corn production and processing (7). Additionally, consumption of corn, peanuts, and cottonseeds contaminated with aflatoxin causes death in animals and humans (8). ...
A variety of essential oils and edible compounds have been widely recognized for their antifungal activity in recent years. In this study, we explored the antifungal activity of estragole from Pimenta racemosa against Aspergillus flavus and investigated the underlying mechanism of action. The results showed that estragole had significant antifungal activity against A. flavus, with a minimum inhibitory concentration of 0.5 μL/mL against spore germination. Additionally, estragole inhibited the biosynthesis of aflatoxin in a dose-dependent manner, and aflatoxin biosynthesis was significantly inhibited at 0.125 μL/mL. Pathogenicity assays showed that estragole had potential antifungal activity against A. flavus in peanut and corn grains by inhibiting conidia and aflatoxin production. Transcriptomic analysis showed that the differentially expressed genes (DEGs) were mainly related to oxidative stress, energy metabolism, and secondary metabolite synthesis following estragole treatment. Importantly, we experimentally verified reactive oxidative species accumulation following downregulation of antioxidant enzymes, including catalase, superoxide dismutase, and peroxidase. These results suggest that estragole inhibits the growth and aflatoxin biosynthesis of A. flavus by modulating intracellular redox homeostasis. These findings expand our knowledge on the antifungal activity and molecular mechanisms of estragole, and provide a basis for estragole as a potential agent against A. flavus contamination. IMPORTANCE Aspergillus flavus contaminates crops and produces aflatoxins, carcinogenic secondary metabolites which pose a serious threat to agricultural production and animal and human health. Currently, control of A. flavus growth and mycotoxin contamination mainly relies on antimicrobial chemicals, agents with side effects such as toxic residues and the emergence of resistance. With their safety, environmental friendliness, and high efficiency, essential oils and edible compounds have become promising antifungal agents to control growth and mycotoxin biosynthesis in hazardous filamentous fungi. In this study, we explored the antifungal activity of estragole from Pimenta racemosa against A. flavus and investigated its underlying mechanism. The results demonstrated that estragole inhibits the growth and aflatoxin biosynthesis of A. flavus by modulating intracellular redox homeostasis.
... Aflatoxins (AF) and zearalenone (ZEA) are among the most worrying mycotoxins. The AF are synthesized by Aspergillus flavus and Aspergillus parasiticus, which contaminate a variety of cattle food and fodder, causing significant economic losses in the livestock industry (Mitchell et al., 2016). The generated metabolites from the ingestion of AF have physicochemical properties that give them the capacity to produce toxic and carcinogenic damage, especially in the organs involved in the elimination of xenobiotics (Benkerroum 2020). ...
The objective of the study was to identify the presence of toxigenic fungi Aspergillus spp. and Fusarium spp. in domestic flies collected from dairy farms. We selected 10 dairy farms distributed in the central valley of the state of Aguascalientes, México. The flies were trapped using entomological traps with an olfactory attractant in 7 sites of the farm (silo-cutting surface, feed store, milking parlor, 3 feeders, and the rearing room). The fungi were cultivated in Sabouraud agar through direct sowing by serial dilutions to obtain the isolates, and a taxonomical identification was carried out under the microscope. The aflatoxins and zearalenone production capacity of the pure isolates were quantified using the ELISA test. The flies were present in all of the capture sites (45.3 flies, 567 mg, trap per day). We obtained 50 isolates of Aspergillus spp. genus, 12 of which produced aflatoxins (327 ± 143 µg/kg), whereas from 56 of the Fusarium spp. isolates, 10 produced large quantities of zearalenone (3,132 ± 665 µg/kg). These results suggest that the presence of domestic flies on dairy farms can constitute a source of dissemination for toxigenic fungi that can eventually contaminate grains and forage that are part of the daily cattle diet.
... 23 Agricultural commodities that contain AFs above the MLs are not safe and are rejected at the border. 24 Therefore, it is of great importance to mitigate the contamination of AF-producing fungi and reduce the risk of AF contamination. ...
Aflatoxins (AFs) are a family of mycotoxins produced by molds in agricultural products. To deal with this problem, one of the control methods is the biological solution using a non-pathogenic strain Aspergillus flavus NRRL 21882 (Afla-Guard). This study was conducted to evaluate the potential of A. flavus NRRL 21882 to control the AF contamination of corn in the field and during storage in 2018 and 2019. The experimental design consists of treatment at different vegetative stages of infested corn in the field trial. After the field has been harvested, half the corn kernels from both treated and control plots were treated with biopesticide; the other half of the kernels from each group were not treated and used as the control of the storage. Consequently, storage applications consisted of kernels: (1) not treated at all; (2) treated prior to storage; (3) field-treated; and (4) treated both in the field and prior to storage. After field trials, the AF content was very low in the treated plots, ranging from 0.50 to 1.04 μg/kg and from 0.50 to 0.73 μg/kg in 2018 and 2019, respectively, while the AF content in the control was 98.3 and 73.9 μg/kg in 2018 and 2019, respectively. After storage, corn kernels from field plots that were treated with the biopesticide (treated/control) showed low levels of AFs, even after they have been stored under conditions conducive to AF contamination. The biopesticide effect ranged from 98 to 99% and from 69 to 99% in the field and during storage, respectively. This paper has provided the first indications on AF biocontrol based on a competitive exclusion in the corn-growing region of Turkey. The data showed that spraying during the storage period did not provide any further prevention of AF contamination, and only treatment in the field had a significant effect on AFs that occurred in storage.
... In the harvesting and storage stages, Aspergillus and Penicillium are the predominant species [1]. The primary toxic effects of mycotoxins on humans and livestock result from the consumption of contaminated seeds or edible plant parts [3]. Mycotoxins are currently classified according to their chronic effects into mutagens, carcinogens or teratogens. ...
The phytotoxic mechanisms of patulin (PAT) and penicillic acid (PA) have not been identified unambiguously. This study aims to clarify their effects on thioredoxins (Trxs). Aflatoxin B1 (AFB1), PAT and PA were isolated by solvent extraction and chromatographic techniques from the cultures of Aspergillus flavus Z2 (LC171449), Penicillium vulpinum CM1 and Aspergillus ochraceus EMCC516, respectively. The three mycotoxins showed phytotoxicity to the germination of maize seeds, which was manifested by inhibiting radicle and coleoptile emergence, in addition to their toxic effects on fresh weights and root and shoot lengths. The phytotoxicity of AFB1 and PAT was greater than that of PA. Due to the central roles exhibited by plant Trxs in cellular metabolic activities, they were tested as target proteins for PAT and PA using AFB1 as positive control. In vivo studies showed that the mycotoxins significantly reduced Trx activity measured in the roots and shoots of maize seedlings. PAT showed greater Trx-inhibiting activity than PA and AFB1. In vitro studies of the mycotoxins on Trx y1 (from Arabidopsis thaliana) and thioredoxin reductase (Tr, from rat liver) activities confirm the results of in vivo studies. The inactivation of Trx with PAT and PA was reduced in the presence of glutathione (GSH). Data obtained suggest that lactone mycotoxins are more highly reactive with simple low-molecular-weight thiols (like GSH) than with complex ones (like Trx).
... Aflatoxins (AFs) are mycotoxins produced by fungi species, especially the genus Aspergillus, including A. flavus, A. parasiticus, A. nomius, A. niger, and A. pseudotamarii [1][2][3]. The biosynthesis of AFs by fungi is driven under certain climatic conditions, including a temperature range of 25-35 • C and relative humidity of 80 to 100%, as typical in Sub-Saharan Africa [2,4], resulting in food spoilage [2,5,6] and significant economic loss [7]. AFs are classified, based on absorbance wavelengths and chromatographic mobility, into aflatoxin B 1 (AFB 1 ), aflatoxin B 2 (AFB 2 ), aflatoxin G 1 (AFG 1 ), and aflatoxin G 2 (AFG 2 ). ...
Aflatoxin B1 (AFB1) is a recalcitrant metabolite produced by fungi species, and due to its intoxications in animals and humans, it has been classified as a Group 1 carcinogen in humans. Preserving food products with Sorghum bicolor sheath can minimise the contamination of agricultural products and avert ill health occasioned by exposure to AFB1. The current study investigated the ameliorating effect of Sorghum bicolor sheath hydrophobic extract (SBE-HP) enriched in Apigenin (API) on the hepatorenal tissues of rats exposed to AFB1. The SBE-HP was characterised using TLC and LC-MS and was found to be enriched in Apigenin and its methylated analogues. The study used adult male rats divided into four experimental cohorts co-treated with AFB1 (50 µg/kg) and SBE-HP (5 and 10 mg/kg) for 28 days. Biochemical, enzyme-linked immunosorbent assays (ELISA) and histological staining were used to examine biomarkers of hepatorenal function, oxidative status, inflammation and apoptosis, and hepatorenal tissue histo-architectural alterations. Data were analysed using GraphPad Prism 8.3.0, an independent t-test, and a one-way analysis of variance. Co-treatment with SBE-HP ameliorated an upsurge in the biomarkers of hepatorenal functionality in the sera of rats, reduced the alterations in redox balance, resolved inflammation, inhibited apoptosis, and preserved the histological features of the liver and kidney of rats exposed to AFB1. SBE-HP-containing API is an excellent antioxidant regiment. It can amply prevent the induction of oxidative stress, inflammation, and apoptosis in the hepatorenal system of rats. Therefore, supplementing animal feeds and human foods with SBE-HP enriched in Apigenin may reduce the burden of AFB1 intoxication in developing countries with a shortage of effective antifungal agents.
... On the other hand, there are many different types of aflatoxins other than four major types are P1, Q1, B2a, and G2a. These are mammalian biotransformation products, which are obtained from the major metabolites [21][22][23]. For instance, the cow milk has the aflatoxins M1 which is hydroxylated derivatives of the B1 aflatoxin, and it is obtained from the feeds of animals, which is contaminated by the molds [24]. ...
Aflatoxins are the carcinogenic, mutagenic and highly toxic secondary metabolite, which is produced by two species of fungus such as Aspergillus flavus and Aspergillus parasiticus mostly. These two types of fungus contaminate the cereals crops such as maize, cotton, rice and spices. These are naturally occurring toxins all over the world. There are 20 different types of aflatoxins but out of six have significance importance for instance, AFB1, AFB2, AFG1, AFG2, AFM1 and AFM2. Most commonly, AFB1 and AFB2 are present in the maize crops and M1 and M2 present in the milk and dairy products. Even the small amounts of aflatoxins, which may cause the harmful effects in human and liver stocks. They cause many acute, subacute and chronic diseases such as hepatic carcinoma in human. Aflatoxins can pose a significant economic burden. It caused up to 25-30 % approximately destroy the crops all over. Aflatoxicosis detection from the humans as well as animals is very tough because variation may occur, or sign and symptoms may be change due to the suppressor of immune system that cause many chronic diseases. These aflatoxins are determined and analyzed by the many techniques such as chromatographic techniques mostly HPLC, immunoassays, fluorescence spectroscopy and many biosensors which are very essential to check the quality, quantity and concentration of aflatoxins present in food and feeds. So that, there are many methods to limit the growth of aflatoxins from the grain in pre-harvest, during harvest and post-harvest conditions or also control the environmental conditions and managed the proper storages of the grains that may diminish the aflatoxins levels. Furthermore, they are many techniques and biological control methods are used to control the growth and activities of fungus species that cause the toxicity in food and feeds and protect the grains for the uses of human and animals.
... GER reduces the yield and quality of kernels and triggers the accumulation of mycotoxins (vomitoxin and zearalenone) which cause serious health problems in humans and animals (Brauner et al. 2017 (Woloshuk and Wise 2011). Aflatoxin contamination of maize is a major problem in the southern parts of the United States (Mitchell et al. 2016). Symptoms of AER include green to yellowish fungal growth on and between grains near the ear tip mostly (Woloshuk and Wise 2011). 5. Fusarium ear rot (FER): This maize disease is prevalent worldwide affecting grain yield and quality that is caused by fungus Fusarium verticillioides (Ding et al. 2008). ...
Biotic stresses are major concerns for the world’s food security. These, commonly induced by diseases and/or insect pests, are one of the primary reasons for maize yield and quality losses. About 10% of the annual maize production is reduced because of biotic stresses globally. Diseases, particularly by fungal pathogens, lead to significant yield decline. Among the insect pests, the herbivorous insects are the major culprits of total yield losses. Moreover, the origin of new pathogens and insects, evolution of new races or strains with time due to climate change and development of pesticide resistance are the other major concerns. Development and deployment of stress-tolerant genotypes is the economically and environmentally viable option to manage biotic stresses. In contrast to the cereals like wheat and rice, quantitative resistance is more important in maize owing to its pollination mode and nature of causal organism. The quantitative trait loci (QTLs) or genomic regions imparting tolerance/resistance to pathogens and insect pests have been identified in maize. This chapter is an attempt to archive all these findings in a referable format to be useful for both students and researchers working in biotic stress resistance research area.
... The pollution of food crops by mycotoxins was a widespread problem, and all countries in the world suffered from mycotoxin pollution to varying degrees. Statistical studies have found that the average annual economic loss of corn due to aflatoxin pollution in the United States was 1.68 billion dollars, and in Europe, the toxin pollution of deoxynivalenol was found in more than 44.6% of the tested grains (Qu et al., 2008;Ji et al., 2014;Mitchell et al., 2016). In China, the Ministry of Agriculture has carried out continuous monitoring of wheat mycotoxin pollution for many years and found that the mycotoxin in main wheat producing area was mainly contaminated by deoxynivalenol and zearalenone toxins . ...
In order to find out the contamination of mycotoxins in Triticeae crops of Qinghai-Tibet Plateau, a total of 153 Triticeae crop fruits were collected as target samples, and 22 mycotoxins were tested. High detection rate was found in the Alternaria mycotoxins, including tentoxin (TEN), tenuazonic acid (TEA) and alternariol (AOH) toxins. To further clarify the production rules of Alternaria mycotoxins. A number of 9 high yield toxic strains were selected from 65 bacterial strains and the gene sequences of each were determined. The nine selected Alternaria alternate were cultured under specific pH of the culture medium, temperature and ultraviolet (UV) irradiation, and their growth and toxicity were analyzed. The results showed that the toxic capacity of most A. alternate increased with the increase of culture environment temperature and decreased with the increase of UV irradiation. However, the production of some toxins did not meet this principle, or even met the principle of relativity. In the culture experiments, a total of five Alternaria toxins were detected as positive, which were TEN, AOH, alternariol monomethyl ether (AME), TEA, and Alternaria (ALT). The altenusin (ALS) toxin was not detected in the metabolites of the nine Alternaria strains. It indicated that the TEN, AOH, AME, TEA, and ALT toxins should be particularly valued in the future risk assessments. This finding provided comprehensive information of mycotoxins contamination in the Tibetan Plateau Triticeae crops, it pointed out a direction to the Tibetan Plateau food crops’ quality control.
... /fsufs. . (Mitchell et al., 2016). By contrast, mycotoxins are a persistent and larger-scale issue in less-developed countries, where such contamination is poorly controlled, if it is controlled at all. ...
Mycotoxins, such as aflatoxins, fumonisins, trichothecenes, and zearalenone, are increasing in visibility as a public health threat through both acute and chronic exposure in food. USAID through its Feed the Future program has sponsored research in Nepal on mycotoxin contamination and the correlated high levels of stunting in children under age five. Communicating about mycotoxins is a complicated matter, as is communicating about any potentially serious economic or health threat that may be difficult to control. Two nominal group workshops in Nepal focused on identifying problems from multiple perspectives and developing potential communication strategies to mitigate the problem and potential concerns about it. Target audiences were identified along with their interests and effective channels to communicate with and within them. The first audience to work with is the government, as it must understand and value the problem and help generate confidence in potential regulatory and mitigation processes. Producers, educators and health professionals are the next audiences to address as they are the most closely involved with the problem. Consumer engagement is last, with a communication goal of sharing information to heighten awareness and minimize unwarranted public concern.
... Mycotoxin contamination has adverse effects on the food chain, especially severely affecting corn and maize yields, which eventually disturbs economic outcomes. 5 It is difficult to prevent and control mycotoxin contamination in the food chain. The infection of molds can occur at various stages of food and feed production. ...
... These aflatoxigenic fungi infect and contaminate crops such as maize, peanut, cotton, and tree nuts. 1 In addition to posing high health risks for humans and livestock, aflatoxin contamination results in significant economic losses because of crop disposal. 2 Thus, effective methods for its control are required. For this purpose, elucidation of the regulatory mechanism underlying aflatoxin production is important. ...
Aflatoxins are toxic secondary metabolites produced by some aspergilli, including Aspergillus flavus. Recently, ethanol has attracted attention as an agent for the control of aflatoxin contamination. However, as aflatoxin biosynthesis utilizes acetyl coenzyme A, ethanol may be conversely exploited for aflatoxin production. Here, we demonstrated that not only the 13C of labeled ethanol, but also that of labeled 2-propanol, was incorporated into aflatoxin B1 and B2, and that ethanol and 2-propanol upregulated aflatoxin production at low concentrations (
... Saprotrophic fungi are key players in nutrient cycles, whereas pathogenic fungi affect other fungi, bacteria, plants, and animals, including human beings (Lutzoni et al. 2004). Besides, fungi have a negative impact on human societies and economies, being responsible for economic losses in fields such as health and agriculture (Bhatnagar et al. 2002;Cleveland et al. 2003;De Lucca 2007;Mitchell et al. 2016;Wagacha and Muthomi 2008). Fortunately, their positive impact is also noteworthy, since they are some of the most relevant producers of pharmaceutical secondary metabolites such as antibiotics, only surpassed by Actinobacteria (Barreiro et al. 2012a). ...
Plant biomass is a promising substrate for biorefinery, as well as a source of bioactive compounds, platform chemicals, and precursors with multiple industrial applications. These applications depend on the hydrolysis of its recalcitrant structure. However, the effective biological degradation of plant cell walls requires several enzymatic groups acting synergistically, and novel enzymes are needed in order to achieve profitable industrial hydrolysis processes. In the present work, a feruloyl esterase (FAE) activity screening of Penicillium spp. strains revealed a promising candidate (Penicillium rubens Wisconsin 54–1255; previously Penicillium chrysogenum), where two FAE-ORFs were identified and subsequently overexpressed. Enzyme extracts were analyzed, confirming the presence of FAE activity in the respective gene products (PrFaeA and PrFaeB). PrFaeB-enriched enzyme extracts were used to determine the FAE activity optima (pH 5.0 and 50–55 °C) and perform proteome analysis by means of MALDI-TOF/TOF mass spectrometry. The studies were completed with the determination of other lignocellulolytic activities, an untargeted metabolite analysis, and upscaled FAE production in stirred tank reactors. The findings described in this work present P. rubens as a promising lignocellulolytic enzyme producer.
Key points
• Two Penicillium rubens ORFs were first confirmed to have feruloyl esterase activity.
• Overexpression of the ORFs produced a novel P. rubens strain with improved activity.
• The first in-depth proteomic study of a P. rubens lignocellulolytic extract is shown.
... [3][4][5] The producer's profile will be significantly impacted by reduced market value or lost access to high-profile international trade for contaminated maize. The aflatoxins contamination caused a loss of $160 million annually in the USA for the maize industry, [6] and failures in sub-Saharan Africa reached $450 million per year. [7] Eskola et al. [8] concluded that about 60% to 80% of global cereals are contaminated with mycotoxins, which is higher than the 25% estimation reported by the Food and Agricultural Organization of the United Nations (FAO). ...
Aflatoxins are potent carcinogens that cause serious health and economic problems worldwide. Maize is one of the most important food crops globally, which is easily contaminated by aflatoxins during the whole process from field to table. The development of emerging decontamination methods is vital to protect human health. This article reviewed the occurrence, regulations, and decontamination technologies of aflatoxins in maize. The decontamination mechanisms, applications, advantages, and limitations of emerging technologies (including cold plasma, ozonation, electromagnetic radiations, biological methods and plant extracts) are discussed. Finally, current challenges and future trends in decontamination technologies are proposed. Emerging decontamination technology has great potential when applied to the decontamination of aflatoxin in maize because they are sustainable, effective, with minimal impact on the quality of the maize. The decontamination efficiency depends on food properties (moisture content, constituents, pH), detoxification methods, and operating conditions. It is critical to analyze the decontamination mechanisms of novel technologies and impacts on the food composition. Future research should focus on the synergy of these novel technologies and evaluate decontamination toxicology to ensure their safety while improving efficiency.
... It can produce teratogenic and carcinogenic aflatoxins that pose a serious safety hazard to both humans and animals [3]. It is estimated that aflatoxin contamination costs the US corn industry nearly USD 1.68 billion annually [4]. Aflatoxin causes 28% of hepatocellular carcinoma worldwide [5]. ...
Aflatoxin, a carcinogenic secondary metabolite produced by Aspergillus flavus, is a significant threat to human health and agricultural production. Histone 2-hydroxyisobutyrylation is a novel post-translational modification that regulates various biological processes, including secondary metabolism. In this study, we identified the novel histone 2-hydroxyisobutyryltransferase Afngg1 in A. flavus, and explored its role in cell growth, development and aflatoxin biosynthesis. Afngg1 gene deletion markedly decreased lysine 2-hydroxyisobutyrylation modification of histones H4K5 and H4K8 compared with the control strain. Additionally, Afngg1 deletion inhibited mycelial growth of A. flavus, and the number of conidia and hydrophobicity were significantly decreased. Notably, aflatoxin B1 biosynthesis and sclerotia production were completely inhibited in the ΔAfngg1 strain. Furthermore, the pathogenicity of the ΔAfngg1 strain infecting peanut and corn grains was also diminished, including reduced spore production and aflatoxin biosynthesis compared with A. flavus control and Afngg1 complementation strains. Transcriptome analysis showed that, compared with control strains, differentially expressed genes in ΔAfngg1 were mainly involved in chromatin remodelling, cell development, secondary metabolism and oxidative stress. These results suggest that Afngg1 is involved in histone 2-hydroxyisobutyrylation and chromatin modification, and thus affects cell development and aflatoxin biosynthesis in A. flavus. Our results lay a foundation for in-depth research on the 2-hydroxyisobutyrylation modification in A. flavus, and may provide a novel target for aflatoxin contamination prevention.
... Aflatoxins are a class of troublesome natural toxins, and fungi producing aflatoxins can colonize many food crops, such as corn, maize, wheat, rice, and groundnuts. In the U.S., aflatoxins was estimated to cause $52.1 million and $1.68 billion losses to the corn industry annually (Mitchell et al. 2016). On a global scale, the negative impacts of chemical hazards on food safety and their risks are efficiently reduced or managed by applying good food manufacturing practices or well-defined regulations to limit the exposure to food contaminants (Arisseto-Bragotto, Feltes, and Block 2017; Barlow et al. 2015;Islam and Hoque 2013). ...
Rigorous risk assessment of chemicals in food and feed is essential to address the growing worldwide concerns about food safety. High-quality toxicological data on food-relevant chemicals are fundamental for risk modeling and assessment in the food safety area. The organization and analysis of substantial toxicity information can positively support decision-making by providing insight into toxicity trends. However, it remains challenging to systematically obtain fragmented toxicity data, and related toxicological resources are required to meet the current demands. In this study, we collected 221,439 experimental toxicity records for 5,657 food-relevant chemicals identified from extensive databases and literature, along with their information on chemical identification, physicochemical properties, environmental fates, and biological targets. Based on the aggregated data, a freely available web-based databank, Food-Relevant Available Chemicals Toxicology Databank (FRAC-TD) is presented, which supports multiple browsing ways and search criterions. Applying FRAC-TD for data-driven analysis, we revealed the underlying toxicity profiles of food-relevant chemicals in humans, mammals, and other species in the food chain. Expectantly, FRAC-TD could positively facilitate toxicological studies, toxicity prediction, and risk assessments in the food industry.
Aflatoxin (AF) is a powerful carcinogen primarily produced by some strains of the fungus Aspergillus flavus and Aspergillus parasiticus, which frequently infest nuts and cereal crops. Groundnuts are among the most widely studied substrates of Aspergillus spp., growth and AF contamination. Aflatoxin contamination is a significant public health concern since chronic exposure is linked to causing carcinogenicity, teratogenicity, hepatotoxicity, estrogenicity, neurotoxicity, childhood growth impairment, and immunotoxicity in humans and animals. Acute exposure to AF contamination is associated with fatal aflatoxicosis due to nausea, vomiting, abdominal pain, and convulsions. Good agricultural practices, control of plant diseases, and favourable storage conditions can limit AF contamination yet do not guarantee complete elimination. Looking for an effective technique to reduce AF to an acceptable regulatory limit has been a great subject among researchers. Physical methods like manual visual sorting, screening, density, roasting, dehulling, winnowing, and decortication can reduce AF contamination while maintaining the quality of the kernel and render the kernels harmless to humans and animals compared to AF degradation by chemicals. Therefore, the present review article found that physical removal/visual sorting efficiently lowered the mean AF content commonly used in low-income countries. We briefly enumerated the effectiveness of various common physical methods in reducing post-harvest AF contamination in groundnuts, particularly their percentage AF reduction and outsort/loss, sufficient AF reduction evidence, feasibility, and scalability. We also highlighted the merits and demerits of these methods and essential information that could be helpful for further investigation.
Aflatoxin contamination of maize ( Zea mays L.) grain presents risks to animal and human health and causes economic losses for growers, particularly in the southeastern United States. Development of hybrids with genetic resistance to aflatoxin contamination by Aspergillus flavus will reduce these risks. Two factorial crossing experiments were conducted to evaluate yield, agronomic traits, and aflatoxin in maize hybrids. In Experiment 1, 18 aflatoxin‐resistant (GT) lines were each crossed to six testers. In Experiment 2, 13 of the same lines were each crossed to 10 different testers. Each experiment was conducted for 2 years at Tifton, GA, and commercial check hybrids were included for comparison. Ears were inoculated with A. flavus isolate NRRL 3357 using the side‐needle technique 14 days after silking. Aflatoxin was quantified after harvest. Broad sense heritability for aflatoxin was low in Experiment 1 ( H ² = 0.09) but was higher in Experiment 2 ( H ² = 0.27). Heritability was moderate to high for plant height ( H ² = 0.49–0.51) and days to silking ( H ² = 0.54–0.72). Among experimental lines, GT1209 and GT1309 had consistent positive general combining ability (GCA) for yield, whereas GT1203 and GT1204 had consistent negative (favorable) GCA for aflatoxin. Significant GCA effects, both positive and negative, for aflatoxin were also observed among testers in both experiments. Some experimental hybrids had yields that were comparable to commercial checks while also having lower aflatoxin, demonstrating the progress made in improvement of both traits in maize hybrids adapted to the Southern United States.
The demand for tree nuts has significantly grown in recent years as epidemiological studies and clinical intervention trials demonstrated an inverse relationship between tree nut consumption and chronic diseases. However, mycotoxins are one of the main hazards responsible for increased "Rapid Alert System for Food and Feed" (RASFF) notifications and border rejections on nuts and nut products exported to the E.U. countries in the past few years. Mycotoxins are secondary metabolites that present serious threats to human and animal health. The most prevalent, toxic, and carcinogenic mycotoxins observed in human food and animal feed are the aflatoxins (AFs). This work analyzed notifications from the RASFF on nuts and nut products contaminated with mycotoxins, for a 10-year period from 2011 to 2021. A total of 4752 mycotoxin notifications were published on RASFF for food products worldwide, 63% (n = 3000) were notified in "nuts, nut products and seeds". It was observed that 95% (n = 2669) notifications were due to AFs. Over half of these notifications (52%, n = 1545) were reported for groundnuts, where 29% (n = 441) of the notifications were received for groundnuts from China alone. Border rejection was reported for 91% (n = 2560) of the nuts and nut products which received the notifications from the E.U. countries. This study proffers understanding into the major reasons for RASFF notifications on nuts and nut products exported to E.U. countries. Also, the implications of this issue with some recommendations that could reduce the incidents of notifications for tree nuts have been outlined.
Highlights
Kernels were artificially inoculated with toxigenic and non-toxigenic strains of Aspergillus flavus in the lab.
Corn kernel mechanical strength was assessed as single kernel compression rupture force (CRF).
Fungus-infected kernels had lower mechanical strength than the controls.
Kernels with high aflatoxin contamination had lower mechanical strength than others.
ABSTRACT . One persistent food safety issue associated with corn is aflatoxin contamination. Aflatoxins are secondary metabolites produced mainly by the fungi Aspergillus flavus (A. flavus) and A. parasiticus. Under environmental conditions suitable for fungal growth and aflatoxin production, these fungi are capable of infecting corn kernels in the field and in storage. When corn kernels are infected, the fungi use nutrients from the kernels to grow and propagate. In general, moldy and contaminated kernels are discolored and lighter in weight. These features could aid in the identification and removal of infected kernels. The objective of this research was to investigate the relationship between the mechanical strength of corn kernels and fungal infection, as well as aflatoxin contamination as a consequence of fungal infection. Corn kernels were infected with aflatoxin producing (AF13) and non-toxin-producing (AF36) A. flavus strains in lab inoculations. A total of 900 kernels were assigned to three groups, non-inoculated control, AF13-inoculated, and AF36-inoculated. One hundred kernels from each group were incubated for 3, 5, and 8 days. After incubation each kernel was cleaned and dried, then subjected to a destructive mechanical test. The compression rupture force (CRF) of each kernel was measured using a Mark-10 material test gauge to assess its kernel strength. The results show that kernel strength was significantly different between the control and treatment groups, with the control kernels being the strongest and the AF36-inoculated kernels the weakest. The results also indicated that kernels with aflatoxin contamination of 300 ppb and above were significantly weaker than control kernels and those less contaminated in the AF13-inoculated group. It is expected that the results of this research could benefit the corn industry by mitigating the aflatoxin contamination problem in post-harvest management. Keywords: Aflatoxin, Aspergillus flavus, Compression rupture force, Corn, Fungus-infected, Inoculation, Mechanical strength.
Mycotoxins are highly toxic compounds, which produced by mycotoxigenic fungi and contaminate foodstuffs resulting in many deleterious effects on human and livestock health. The main producers are belonging to the genera Aspergillus, Penicillium, Fusarium, and Alternaria. Mycotoxins can be found singly or in a co-occurrence (more than one type). Their toxic effects include acute or chronic mycotoxicosis, oncogenesis, mutagenesis, hepatotoxicity, nephrotoxicity, embryotoxicity, immunosuppression and other complications. Annually, high percentages of harvested crops have been contaminated with mycotoxigenic fungi causing highly economical losses in agricultural and food industry sectors. Various control strategies have been described during pre-harvest, post-harvest, and food processing stages including prevention and decontamination/detoxification methods to eliminate/reduce the mycotoxins. In this chapter, diversity and occurrence of mycotoxins, their side effects, producing fungi, as well as their control measures in foodstuffs will be highlighted.KeywordsAflatoxinsFumonisinsOchratoxinsPatulinTrichothecenesZearalenone
Maize gluten meal (MGM) is a by-product of maize starch and ethanol, produced by the wet milling process. Its high protein content makes it a preferred ingredient in feed. Given the high prevalence of mycotoxins in maize globally, they pose a significant challenge to use of MGM for feed: wet milling could concentrate certain mycotoxins in gluten components, and mycotoxin consumption affects animal health and can contaminate animal-source foods. To help confront this issue, this paper summarizes mycotoxin occurrence in maize, distribution during MGM production and mycotoxin risk management strategies for MGM through a comprehensive literature review. Available data emphasize the importance of mycotoxin control in MGM and the necessity of a systematic control approach, which includes: good agriculture practices (GAP) in the context of climate change, degradation of mycotoxin during MGM processing with SO2 and lactic acid bacteria (LAB) and the prospect of removing or detoxifying mycotoxins using emerging technologies. In the absence of mycotoxin contamination, MGM represents a safe and economically critical component of global animal feed. With a holistic risk assessment-based, seed-to-MGM-feed systematic approach to reducing and decontaminating mycotoxins in maize, costs and negative health impacts associated with MGM use in feed can be effectively reduced.
Aspergillus flavus (A. flavus) is a common saprophytic pathogenic fungus that produces toxic and carcinogenic aflatoxins prone to contaminate food. Here, we optimized the synthesis method of Ar-turmerone, the main active ingredient in turmeric essential oil, improved its yield and reduced the operation requirements. Moreover, 50.0 μg/mL Ar-turmerone 100.0 % inhibited the colonies growth, spore germination, mycelium biomass and aflatoxin accumulation in 7 days. 2,018 differentially expressed genes (DEGs) such as catA, ppoC, erg7, erg6 and aflO related to the A. flavus growth and aflatoxin product were significantly downregulated including 45 DEGs were 100.0 % suppressed. Besides, Ar-turmerone greatly reduced A. flavus in maize, the optimal storage conditions for maize to avoid A. flavus contamination were determined as 0.940 aw, 400.0 μg/mL Ar-turmerone, and 16.0 °C. Satisfactory odor, luster, taste, and mildew in maize observed after three weeks of storage under the optimal conditions. Thus, Ar-turmerone can be used as a potential food antifungal agent against A. flavus growth and aflatoxin accumulation during food storage.
Aflatoxin B1 (AFB1) is a serious pollutant in feed and food which causes liver inflammation, fibrosis, and even cirrhosis. The Janus kinase 2 (JAK2)/signal transducers and activators of the transcription 3 (STAT3) signaling pathway is widely involved in inflammatory response and promotes the activation of nod-like receptor protein 3 (NLRP3) inflammasome, thus leading to pyroptosis and fibrosis. Curcumin is a natural compound with anti-inflammatory and anti-cancer properties. However, whether AFB1 exposure leads to the activation of the JAK2/NLRP3 signaling pathway in the liver and whether curcumin can regulate this pathway to influence pyroptosis and fibrosis in the liver remains unclear. In order to clarify these problems, we first treated ducklings with 0, 30, or 60 µg/kg AFB1 for 21 days. We found that AFB1 exposure caused growth inhibition, liver structural and functional damage, and activated JAK2/NLRP3-mediated liver pyroptosis and fibrosis in ducks. Secondly, ducklings were divided into a control group, 60 µg/kg AFB1 group, and 60 µg/kg AFB1 + 500 mg/kg curcumin group. We found that curcumin significantly inhibited the activation of the JAK2/STAT3 pathway and NLRP3 inflammasome, as well as the occurrence of pyroptosis and fibrosis in AFB1-exposed duck livers. These results suggested that curcumin alleviated AFB1-induced liver pyroptosis and fibrosis by regulating the JAK2/NLRP3 signaling pathway in ducks. Curcumin is a potential agent for preventing and treating liver toxicity of AFB1.
Mycotoxins, toxic compounds produced by fungi on raw materials, such as cereals, represent a serious health hazard. Animals are exposed to them mainly through the ingestion of contaminated feed. This study presents data about the presence and co-occurrence of nine mycotoxins: aflatoxins B1, B2, G1, and G2, ochratoxins A and B, zearalenone (ZEA), deoxynivalenol (DON), and sterigmatocystin (STER), in 400 samples of compound feed for cattle, pigs, poultry, and sheep (100 samples each) collected in Spain (2019–2020). Aflatoxins, ochratoxins, and ZEA were quantified using a previously validated HPLC method using fluorescence detection; whereas DON and STER were quantified using ELISA. Moreover, the obtained results were compared with those obtained in this country and published in the last 5 years. The mycotoxin presence in Spanish feed, especially for ZEA and DON, has been demonstrated. The maximum individual levels found were: AFB1: 6.9 µg/kg in a sample of feed for poultry; OTA: 65.5 µg/kg in a sample of feed for pigs, DON: 887 µg/kg in a sample of feed for sheep, and ZEA: 816 µg/kg in a sample of feed for pigs. Nevertheless, regulated mycotoxins appear, in general, at levels below those regulated by the EU; in fact, the percentage of samples containing concentrations above these limits was very low (from 0% for DON to 2.5% for ZEA). The co-occurrence of mycotoxins has also been demonstrated: 63.5% of the analyzed samples presented detectable levels of two to five mycotoxins. Due to the fact that the distribution of mycotoxins in raw materials can change greatly from year to year with climate conditions or market globalization, regular mycotoxin monitorization in feed is needed to prevent the integration of contaminated materials in the food chain.
Aspergillus flavus infects stored grains and produces aflatoxins with highly toxic and carcinogenic properties, which are a threat to food safety and human health. Microbes and their bio-active compounds are considered effective agents to control A. flavus and aflatoxins during the pre- and post-harvest stages. Here, we reveal that Bacillus flexus strain TR-1 isolated from tea plant rhizosphere soil could efficiently inhibit the growth of A. flavus in dual culture tests through the production of antifungal volatiles. Additionally, these volatiles showed great inhibitory effects against A. flavus infection and aflatoxin production in maize and peanut with high water activity levels during storage. Scanning electron microscope analysis further proved that the conidia of A. flavus on the peanut surface treated with TR-1 volatiles could not germinate and were severely dehydrated and shrunken. Gas chromatography-tandem mass spectrometry revealed that five antifungal compounds were identified in the volatile profiles, including benzene, methyl thiolacetate, dimethyl disulfide, butanethioic acid S-methyl ester analogue, dimethyl trisulfide (DMTS), and S-methyl 3-methylbutanethioate. DMTS, with the best antagonistic effect, completely inhibited the growth of A. flavus at 10 μl−1 (compound volume/airspace volume). TR-1 also exhibited efficient and broad inhibitory effects against six other fungal pathogens. Overall, B. flexus strain TR-1 and its produced volatiles showed valid antifungal activity against phytopathogens. This study provides novel materials for the production of bioactive agents to control plant pathogens in stored grains.
Global population growth tremendously impacts the global food industry, endangering food safety and quality. Mycotoxins, particularly Ochratoxin-A (OTA), emerge as a food chain production threat, since it is produced by fungus that contaminates different food species and products. Beyond this, OTA exhibits a possible human toxicological risk that can lead to carcinogenic and neurological diseases. A selective, sensitive, and reliable OTA biodetection approach is essential to ensure food safety. Current detection approaches rely on accurate and time-consuming laboratory techniques performed at the end of the food production process, or lateral-flow technologies that are rapid and on-site, but do not provide quantitative and precise OTA concentration measurements. Nanoengineered optical biosensors arise as an avant-garde solution, providing high sensing performance, and a fast and accurate OTA biodetection screening, which is attractive for the industrial market. This review core presents and discusses the recent advancements in optical OTA biosensing, considering engineered nanomaterials, optical transduction principle and biorecognition methodologies. Finally, the major challenges and future trends are discussed, and current patented OTA optical biosensors are emphasized for a particular promising detection method.
Mycotoxin contamination in medicinal foods has attracted increasing global attention. In this study, a simple and sensitive ultrasonication assisted one-step extraction based ultra-fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) method was developed for simultaneous detection of multi-mycotoxins in five kinds of medicinal foods rich in starch. Under optimal conditions, the developed technique displayed excellent analytical performances. Limits of detection and quantitation for the six mycotoxins were 0.04-0.25 ng/mL and 0.10-0.67 ng/mL, respectively. Average recoveries at three fortified levels ranged from 75.33 % to 118.0 %. Real-world application in 103 batches of medicinal foods displayed that 58 samples were positive with one or more mycotoxins at an occurrence rate of 56.31 % (58/103). Coix seed gave the highest positive rate of 96.15 %, followed by Lily (90 %), Chinese yam (50 %), Lotus seed (34.04 %) and Malt (30 %). Zearalenone had the highest positive rate of 28.16 % with contents in 5 Coix seeds exceeding the maximum residue limit (MRL), followed by aflatoxin B1 of 27.18 % (28/103) with contents in 7 Coix seed and 10 Lotus seeds over its MRL, and ochratoxin A (OTA) of 11.65 % with contents in 1 Lotus seed and 5 Lily samples greater than its MRL. Exposure risk assessment indicated that Coix seed and Lotus seeds that were susceptible to aflatoxins posed great threats to human health. Long-term consumption of Lily that was easily contaminated with OTA were also harmful. This work provides a robust platform for multi-mycotoxin monitoring in medicinal foods to protect the consumers from potential health risks.
Aflatoxins are a group of polyketide mycotoxins that are produced during fungal development as secondary metabolites mainly by members of the Aspergillus section Flavi (Yu et al., 2004; Norlia et al., 2019; Uka et al., 2019). Contamination of food, feed and agricultural commodities by aflatoxins impose an enormous economic concern, as these chemicals are highly carcinogenic,
they can directly influence the structure of DNA (Bbosa et al., 2013; Feng et al., 2016). They can lead to fetal maldevelopment and miscarriages, and are known to suppress immune systems (Ahmed Adam et al., 2017). In a global context, aflatoxin contamination is considered a perennial concern between the 35N and 35S latitude where developing countries are mainly situated. With the expansion of these boundaries, aflatoxins are increasingly becoming a problem in countries
that previously did not have to worry about aflatoxin contamination. Given the continuing problems arising from aflatoxin contamination of food and agricultural commodities throughout the world, aflatoxins research is becoming one of the most exciting and rapidly developing areas of microbial toxins research. The applications include many disciplines, from medicine to agriculture. Nowadays, traditional research on aflatoxins has been expanded to modern technologies such as
omics for understanding the regulation of aflatoxin biosynthetic pathway genes, the taxonomy, ecology, biochemistry, and evolution of aflatoxigenic fungi in addition to strategies to pre- and post-harvest management of aflatoxin contamination. This includes improving host resistance of susceptible crops such as cotton, maize, peanut, and tree nuts via genetic engineering. The present Research Topic includes one review article, one mini-review and fifteen original
research articles. Contributors highlighted challenges and opportunities in mitigating aflatoxins in food and agricultural crops and the current knowledge on the global health issues of aflatoxins and aflatoxigenic fungi. All aspects of aflatoxin contamination of food and agricultural crops from epidemiology to ecology, biochemistry, molecular biology, biocontrol strategies, natural inhibitors
of fungal growth and aflatoxin production, transgenic hosts and pre- and post-harvest management strategies have been discussed.
Aflatoxins (AFs) are the most important toxic, mutagenic, and carcinogenic fungal toxins that routinely contaminate food and feed. While more than 20 AFs have been identified to date, aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1), G2 (AFG2), and M1 (AFM1) are the most common. Over 25 species of Aspergillus have been shown to produce AFs, with Aspergillus flavus, Aspergillus parasiticus, and Aspergillus nomius being the most important and well-known AF-producing fungi. These ubiquitous molds can propagate on agricultural commodities to produce AFs in fields and during harvesting, processing, transportation, and storage. Countries with warmer climates and that produce foods susceptible to AF contamination shoulder a substantial portion of the global AF burden. Pakistan’s warm climate promotes the growth of toxigenic fungi, resulting in frequent AF contamination of human foods and animal feeds. The potential for contamination in Pakistan is exacerbated by improper storage conditions and a lack of regulatory limits and enforcement mechanisms. High levels of AFs in common commodities produced in Pakistan are a major food safety problem, posing serious health risks to the population. Furthermore, aflatoxin contamination contributes to economic losses by limiting exports of these commodities. In this review, recent information regarding the fungal producers of AFs, prevalence of AF contamination of foods and feed, current regulations, and AF prevention and removal strategies are summarized, with a major focus on Pakistan.
Bryophilous fungi associated with two bryophyte species in the region of delta in Tamil Nadu that is, the mosses of Polytrichum commune and Bryum capillare (Ptychostomum capillare) mosses were studied during the winter season. These bryophytes were Desiccation-Tolerance Bryophytes plant (DTB), the ability to lose virtually all free intracellular water and then recover normal function upon rehydration is one of the most remarkable features of bryophytes. Our aims were to identify bryophilous fungi/ endophytic fungi using morphological taxonomy, to explore richness and estimate species frequency in two bryophytes, Polytrichum and Bryum in delta region of Tamil Nadu. We collected two bryophyte samples at old building wall, bricks localities on delta region. We thus identified 32 endophytic fungi species were isolated from these bryophyte plants tissues. In total, 32 endophytic fungal strains belonging to Ascomycetes (04), Coeleomycetes (02), Hyphomycetes (20), sterile forms (02), Yeast like strains (02) and Zygomycetes (02) taxa were obtained. Thus species RPO and diversity index suggest that our study still underestimate endophytes diversity because it does not provide complete samples. These results recommend the presence of a diverse range of fungal species even in a very limited area, and those bryophytes fungal diversity in this Desiccation-Tolerance environment. To our knowledge, this is the first report of endophytic fungi from DT Bryophytes in tropical region.
Aspergillus flavus and the produced aflatoxins cause great hazards to food security and human health across all countries. The control of A. flavus and aflatoxins in grains during storage is of great significance to humans. In the current study, bacteria strain YM6 isolated from sea sediment was demonstrated effective in controlling A. flavus by the production of anti-fungal volatiles. According to morphological characteristics and phylogenetic analysis, strain YM6 was identified as Pseudomonas stutzeri. YM6 can produce abundant volatile compounds which could inhibit mycelial growth and conidial germination of A. flavus. Moreover, it greatly prevented fungal infection and aflatoxin production on maize and peanuts during storage. The inhibition rate was 100%. Scanning electron microscopy further supported that the volatiles could destroy the cell structure of A. flavus and prevent conidia germination on the grain surface. Gas chromatography/mass spectrometry revealed that dimethyl trisulfide (DMTS) with a relative abundance of 13% is the most abundant fraction in the volatiles from strain YM6. The minimal inhibitory concentration of DMTS to A. flavus conidia is 200 µL/L (compound volume/airspace volume). Thus, we concluded that Pseudomonas stutzeri YM6 and the produced DMTS showed great inhibition to A. flavus, which could be considered as effective biocontrol agents in further application.
Mycotoxin contamination of corn results in significant agroeconomic losses and poses serious health issues worldwide. This paper presents the first report utilizing machine learning and historical aflatoxin and fumonisin contamination levels in-order-to develop models that can confidently predict mycotoxin contamination of corn in Illinois, a major corn producing state in the USA. Historical monthly meteorological data from a 14-year period combined with corresponding aflatoxin and fumonisin contamination data from the State of Illinois were used to engineer input features that link weather, fungal growth, and aflatoxin production in combination with gradient boosting (GBM) and bayesian network (BN) modeling. The GBM and BN models developed can predict mycotoxin contamination with overall 94% accuracy. Analyses for aflatoxin and fumonisin with GBM showed that meteorological and satellite-acquired vegetative index data during March significantly influenced grain contamination at the end of the corn growing season. Prediction of high aflatoxin contamination levels was linked to high aflatoxin risk index in March/June/July, high vegetative index in March and low vegetative index in July. Correspondingly, high levels of fumonisin contamination were linked to high precipitation levels in February/March/September and high vegetative index in March. During corn flowering time in June, higher temperatures range increased prediction of high levels of fumonisin contamination, while high aflatoxin contamination levels were linked to high aflatoxin risk index. Meteorological events prior to corn planting in the field have high influence on predicting aflatoxin and fumonisin contamination levels at the end of the year. These early-year events detected by the models can directly assist farmers and stakeholders to make informed decisions to prevent mycotoxin contamination of Illinois grown corn.
To ensure future food security, it is crucial to understand how potential climate change scenarios will affect agriculture. One key area of interest is how climatic factors, both in the near- and the long-term future, could affect fungal infection of crops and mycotoxin production by these fungi. The objective of this paper is to review the potential impact of climate change on three important mycotoxins that contaminate maize in the United States, and to highlight key research questions and approaches for understanding this impact. Recent climate change analyses that pertain to agriculture and in particular to mycotoxigenic fungi are discussed, with respect to the climatic factors – temperature and relative humidity – at which they thrive and cause severe damage. Additionally, we discuss how climate change will likely alter the life cycles and geographic distribution of insects that are known to facilitate fungal infection of crops.
Adherence to regulatory limits for mycotoxins in agricultural commodities is important to safeguard consumers and to permit trade in affected commodities across international borders. Reliable estimates of mycotoxin concentrations are required to implement regulatory decisions on the suitability of lots of produce for consumption or trade. Effective schemes to test for mycotoxins depend not only upon sound analytical methods, but also on well designed and implemented sampling plans. This manual provides information to food analysts and regulatory officials on effective sampling plans to detect mycotoxins in food. The concepts of uncertainty and variability in mycotoxin test procedures are discussed as well as the importance of ensuring that samples are representative of the lot being sampled, and the consequences of a poorly designed sampling plan on the reliability of the measured levels of mycotoxins, possibly resulting in legal disputes and barriers to trade.
Aspergillus flavus has received a considerable amount of attention due to its ability to produce aflatoxin, a secondary metabolite that is both immunosuppressive and carcinogenic to animals and humans. Research on aflatoxin over the last 40 years has made it one of the best studied fungal secondary metabolites. In spite of the large volume of research in this area, many unanswered questions remain concerning the genetic regulation of aflatoxin production and the molecular signals that intimately associate the synthesis of aflatoxin with specific environmental and nutritional conditions. It is anticipated that the tools now available in the field of genomics will build upon our existing knowledge and provide answers to some of these questions. Complete genome sequences are now available for a number of fungal species that are closely related to A. flavus. This information can be used along with current genomic analyses in A. flavus to more closely examine the biosynthesis and regulation of secondary metabolism. The intent of this review is to summarize the large body of knowledge that exists from many years of research on A. flavus, with the hope that this information in the light of new genomic studies may bring scientists closer to unraveling the web of regulatory circuits that govern aflatoxin biosynthesis. Specifically, scientific findings in the following areas will be presented: classification and phylogenetic analyses of A. flavus, population biology, ecology and pathogenicity in agricultural environments , classical genetics including linkage group and mutant analyses, gene clusters, regulation of aflatoxin biosynthesis, and genomics.
Aflatoxins, fungal toxins produced by Aspergillus flavus and Aspergillus parasiticus in a variety of food crops, are well known as potent human hepatocarcinogens. Relatively less highlighted in the literature is the association between aflatoxin and growth impairment in children. Foodborne aflatoxin exposure, especially through maize and groundnuts, is common in much of Africa and Asia--areas where childhood stunting and underweight are also common, due to a variety of possibly interacting factors such as enteric diseases, socioeconomic status, and suboptimal nutrition. The effects of aflatoxin on growth impairment in animals and human children are reviewed, including studies that assess aflatoxin exposure in utero and through breastfeeding. Childhood weaning diets in various regions of the world are briefly discussed. This review suggests that aflatoxin exposure and its association with growth impairment in children could contribute a significant public health burden in less developed countries.
Hepatocellular carcinoma (HCC), or liver cancer, is the third leading cause of cancer deaths worldwide, with prevalence 16-32 times higher in developing countries than in developed countries. Aflatoxin, a contaminant produced by the fungi Aspergillus flavus and Aspergillus parasiticus in maize and nuts, is a known human liver carcinogen.
We sought to determine the global burden of HCC attributable to aflatoxin exposure.
We conducted a quantitative cancer risk assessment, for which we collected global data on food-borne aflatoxin levels, consumption of aflatoxin-contaminated foods, and hepatitis B virus (HBV) prevalence. We calculated the cancer potency of aflatoxin for HBV-postive and HBV-negative individuals, as well as the uncertainty in all variables, to estimate the global burden of aflatoxin-related HCC.
Of the 550,000-600,000 new HCC cases worldwide each year, about 25,200-155,000 may be attributable to aflatoxin exposure. Most cases occur in sub-Saharan Africa, Southeast Asia, and China where populations suffer from both high HBV prevalence and largely uncontrolled aflatoxin exposure in food.
Aflatoxin may play a causative role in 4.6-28.2% of all global HCC cases.
Both aflatoxin and the human immunodeficiency virus (HIV) cause immune suppression and millions of HIV-infected people in developing countries are chronically exposed to aflatoxin in their diets. We investigated the possible interaction of aflatoxin and HIV on immune suppression by comparing immune parameters in 116 HIV positive and 80 aged-matched HIV negative Ghanaians with high (> or =0.91 pmol/mg albumin) and low (<0.91 pmol/mg albumin) aflatoxin B1 albumin adduct (AF-ALB) levels. AF-ALB levels and HIV viral load were measured in plasma and the percentages of leukocyte immunophenotypes and cytokine expression were determined using flow cytometry. The cross-sectional comparisons found that (1) among both HIV positive and negative participants, high AF-ALB was associated with lower perforin expression on CD8+ T-cells (P = .012); (2) HIV positive participants with high AF-ALB had significantly lower percentages of CD4+ T regulatory cells (Tregs; P = .009) and naive CD4+ T cells (P = .029) compared to HIV positive participants with low AF-ALB; and (3) HIV positive participants with high AF-ALB had a significantly reduced percentage of B-cells (P = .03) compared to those with low AF-ALB. High AF-ALB appeared to accentuate some HIV associated changes in T-cell phenotypes and in B-cells in HIV positive participants.
The variability associated with testing lots of shelled corn for aflatoxin was investigated. Eighteen lots of shelled corn were tested for aflatoxin contamination. The total variance associated with testing shelled corn was estimated and partitioned into sampling, sample preparation, and analytical variances. All variances increased as aflatoxin concentration increased. With the use of regression analysis, mathematical expressions were developed to model the relationship between aflatoxin concentration and the total, sampling, sample preparation, and analytical variances. The expressions for these relationships were used to estimate the variance for any sample size, subsample size, and number of analyses for a specific aflatoxin concentration. Test results on a lot with 20 parts per billion aflatoxin using a 1.13 kg sample, a Romer mill, 50 g subsamples, and liquid chromatographic analysis showed that the total, sampling, sample preparation, and analytical variances were 274.9 (CV = 82.9%), 214.0 (CV = 73.1 %), 56.3 (CV = 37.5%), and 4.6 (CV = 10.7%), respectively. The percentage of the total variance for sampling, sample preparation, and analytical was 77.8, 20.5, and 1.7, respectively.
Fetal and early childhood environment, including the nutritional status of the pregnant mother and the infant, are considered critical for growth and risk of disease in later life. Many people in developing coun tries are not only malnourished but also chronically exposed to high levels of toxic fungal metabolites (mycotoxins). One family of mycotoxins, the aflatoxins, are carcinogenic and immunotoxic and cause growth retardation in animals. Aflatoxins contaminate staple foods in West Africa, particularly maize and ground nuts, as a result of hot, humid storage conditions that promote fungal growth. High exposure to aflatoxins occurs throughout childhood in the region, suggest ing that growth and development could be critically affected.We assessed exposure to aflatoxins in relation to anthropometric measures in children in Benin and Togo.
Aflatoxins are well recognized as a cause of liver cancer, but they have additional important toxic effects. In farm and laboratory animals, chronic exposure to aflatoxins compromises immunity and interferes with protein metabolism and multiple micronutrients that are critical to health. These effects have not been widely studied in humans, but the available information indicates that at least some of the effects observed in animals also occur in humans. The prevalence and level of human exposure to aflatoxins on a global scale have been reviewed, and the resulting conclusion was that approximately 4.5 billion persons living in developing countries are chronically exposed to largely uncontrolled amounts of the toxin. A limited amount of information shows that, at least in those locations where it has been studied, the existing aflatoxin exposure results in changes in nutrition and immunity. The aflatoxin exposure and the toxic affects of aflatoxins on immunity and nutrition combine to negatively affect health factors (including HIV infection) that account for >40% of the burden of disease in developing countries where a short lifespan is prevalent. Food systems and economics render developed-country approaches to the management of aflatoxins impractical in developing-country settings, but the strategy of using food additives to protect farm animals from the toxin may also provide effective and economical new approaches to protecting human populations.
Although aflatoxins (AFs) have been shown to be immune-suppressive agents in animals, the potential role of AFs in modifying the distribution and function of leukocyte subsets in humans has never been assessed. We examined the cellular immune status of 64 Ghanaians in relation to levels of aflatoxin B1 (AFB1)-albumin adducts in plasma. The percentages of leukocyte immunophenotypes in peripheral blood, CD4+ T cell proliferative response, CD4+ T(h) and CD8+ T cell cytokine profiles and monocyte phagocytic activity were measured using flow cytometry. NK cell cytotoxic function was determined by perforin and tumor necrosis factor-alpha expression in CD3-CD56+ NK cells. AFB1-albumin adducts levels ranged from 0.3325 to 2.2703 (mean = 0.9972 +/- 0.40, median = 0.9068) pmol mg(-1) albumin. Study participants with high AFB1 levels had significantly lower percentages of CD3+ and CD19+ cells that showed the CD69+ activation marker (CD3+CD69+ and CD19+CD69+) than participants with low AFB1 levels (P = 0.002 for both). Also, the percentages of CD8+ T cells that contained perforin or both perforin and granzyme A were significantly lower in participants with high AFB1 levels compared with those with low AFB1 (P = 0.012 for both). Low levels of CD3+CD69+ (r = -0.32, P = 0.016) and CD19+CD69+ (r = -0.334, P = 0.010) cells were significantly associated with high AFB1 levels using correlation analysis. By multivariate analysis, there were strong negative correlations between the percentages of these cells (CD3+CD69+: b = -0.574, P = 0.001, and CD19+CD69+: b = -0.330, P = 0.032) and AFB1 levels. These alterations in immunological parameters in participants with high AFB1 levels could result in impairments in cellular immunity that could decrease host resistance to infections.
In April 2004, one of the largest aflatoxicosis outbreaks occurred in rural Kenya, resulting in 317 cases and 125 deaths. Aflatoxin-contaminated homegrown maize was the source of the outbreak, but the extent of regional contamination and status of maize in commercial markets (market maize) were unknown. We conducted a cross-sectional survey to assess the extent of market maize contamination and evaluate the relationship between market maize aflatoxin and the aflatoxicosis outbreak. We surveyed 65 markets and 243 maize vendors and collected 350 maize products in the most affected districts. Fifty-five percent of maize products had aflatoxin levels greater than the Kenyan regulatory limit of 20 ppb, 35% had levels > 100 ppb, and 7% had levels > 1,000 ppb. Makueni, the district with the most aflatoxicosis case-patients, had significantly higher market maize aflatoxin than did Thika, the study district with fewest case-patients (geometric mean aflatoxin = 52.91 ppb vs. 7.52 ppb, p = 0.0004). Maize obtained from local farms in the affected area was significantly more likely to have aflatoxin levels > 20 ppb compared with maize bought from other regions of Kenya or other countries (odds ratio = 2.71; 95% confidence interval, 1.12-6.59). Contaminated homegrown maize bought from local farms in the affected area entered the distribution system, resulting in widespread aflatoxin contamination of market maize. Contaminated market maize, purchased by farmers after their homegrown supplies are exhausted, may represent a source of continued exposure to aflatoxin. Efforts to successfully interrupt exposure to aflatoxin during an outbreak must consider the potential role of the market system in sustaining exposure.
Myotis sodalis), including its selection of and use of hibernacula, roost trees, and foraging habitat. An extensive list of published references related to the Indiana bat is included. The Authors MICHAEL A. MENZEL and JOHN W. EDWARDS are wildlife biologists with West Virginia University's Division of Forestry at Morgantown. JENNIFER M. MENZEL and W. MARK FORD are research wildlife biologists with the Northeastern Research Station in Parsons. TIMOTHY C. CARTER is a wildlife biologist with Southern Illinois University's Department of Zoology at Carbondale. Manuscript received for publication 24 May 2001 Contents
Fetal and early childhood environment, including the
nutritional status of the pregnant mother and the
infant, are considered critical for growth and risk of
disease in later life. Many people in developing coun
tries are not only malnourished but also chronically
exposed to high levels of toxic fungal metabolites
(mycotoxins). One family of mycotoxins, the aflatoxins,
are carcinogenic and immunotoxic and cause growth
retardation in animals. Aflatoxins contaminate staple
foods in West Africa, particularly maize and ground
nuts, as a result of hot, humid storage conditions that
promote fungal growth. High exposure to aflatoxins
occurs throughout childhood in the region, suggest
ing that growth and development could be critically
affected.We assessed exposure to aflatoxins in relation
to anthropometric measures in children in Benin and
Togo.
Because of the variability among laboratory sample test results, two types of mistakes are associated with any mycotoxin-sampling plan. First, good lots (lots with a concentration less than or equal to the legal limit) will test bad and be rejected by the sampling plan. The chances of making this type of mistake is often called the seller’s risk (false positives or type I, α error) since these lots will be rejected at an unnecessary cost to the seller of the product. Secondly, bad lots (lots with a concentration greater than the legal limit) will test good and be accepted by the sampling program. The chances of making this type of mistake is called the buyer’s risk (false negatives, or type II, β error) since contaminated lots will be processed into feed or food causing possible health problems and/or economic loss to the buyer of the product.
Mycotoxins are toxic metabolites produced by fungal species that commonly contaminate staple foods and feeds. They represent an unavoidable problem due to their presence in globally consumed cereals such as rice, maize and wheat. Most mycotoxins are immunosuppressive agents and some are carcinogens, hepatotoxins, nephrotoxins, and neurotoxins. Worldwide trends envision a stricter control of mycotoxins, however, the changing global environment may not be the ideal setting to control and reduce the exposure to these toxins. Although new technologies allow us to inspect the multi-mycotoxin presence in foods, new sources of exposure, gaps in knowledge of mycotoxins interactions, appearance of "emergent" mycotoxins and elucidation of consequent health effects can complicate their control even more. While humans are adapting to cope with environmental changes, such as food scarcity, decreased food quality, mycotoxin regulations, crop production and seasonality, and other climate related modifications, fungal species are also adapting and increased cases of mycotoxin adverse health effects are likely to occur in the future. To guarantee access to quality food for all, we need a way to balance global mycotoxin standards with the realistic feasibility of reaching them, considering limitations of producers and designing strategies to reduce mycotoxin exposure based on sound research.
Insect damage, Aspergillus flavus Link infection, and aflatoxin contamination are recurring problems in preharvest corn (Zea mays L.) in the Coastal Plain of Georgia. A 6-yr study (1977-1982) over a 46-county area revealed that insect damage ranged from a mean of 1.7 cm per ear in 1979 to 4.0 cm per ear in 1977. The incidence of aflatoxin contamination in grain samples ranged from 57% in 1982 to 100% in 1980. The highest concentration of aflatoxin (4708 μg kg-1 was recorded in a field sample collected in 1977. The action level set by the Food and Drug Administration for aflatoxin is 20 μg kg-1. Insect damage contributed significantly to enhanced A. flavus sporulation and aflatoxin contamination. Levels of aflatoxin were positively correlated with temperature and total net evaporation. The occurrence of undamaged, uncontaminated corn in the Coastal Plain during a majority of the years suggests that crop management, including hybrid selection, planting date, and irrigation, may have a significant influence on the quantity of quality corn grain produced.
Aflatoxin B1 is a potent hepatacarcinogen that occurs in corn worldwide. The aflatoxin‐producing fungus Aspergillus flavus can grow and produce aflatoxin on corn preharvest and in storage. Within the U.S., aflatoxin contamination of preharvest corn has been reported in 23 states, and contamination is chronic in the southeastern U.S. where hot, drought conditions often favor the fungus and the production of aflatoxin. Management practices have been developed to reduce aflatoxin contamination, but in years when environmental conditions are extremely favorable for the fungus, no control strategy is effective. Resistance to aflatoxin accumulation appears to be heritable, but no commercial hybrids are available with adequate resistance. This review covers the epidemiology of A. flavus in preharvest corn from the infection process to the factors that influence aflatoxin formation. Also discussed are the problems associated with the development of resistant varieties and new strategies that are being developed for control of aflatoxin contamination.
Use of proper sampling methods throughout the agri-food chain is crucial when it comes to effectively detecting contaminants in foods and feeds. The objective of the study was to estimate the performance of sampling plan designs to determine aflatoxin B(1) (AFB(1)) contamination in corn fields. A total of 840 ears were selected from a corn field suspected of being contaminated with aflatoxin. The mean and variance among the aflatoxin values for each ear were 10.6 mug/kg and 2233.3, respectively. The variability and confidence intervals associated with sample means of a given size could be predicted using an equation associated with the normal distribution. Sample sizes of 248 and 674 ears would be required to estimate the true field concentration of 10.6 mug/kg within +/-50 and +/-30%, respectively. Using the distribution information from the study, operating characteristic curves were developed to show the performance of various sampling plan designs.
The aim of this study was to examine the exposure of lactating mothers to aflatoxins using aflatoxin M(1) in breast milk as a biomarker for exposure and to detect its determining factors and possible effects on child growth. A 9% sample of 2022 lactating women who exclusively breastfed their infants, including 91 lactating women of urban areas of Tabriz city and 91 lactating women of its rural areas were recruited by a geographical clustered sampling method. Breast milk samples and information on food intake were collected from subjects using structured food-frequency questionnaire. Extraction of AFM(1) was performed with the ELISA test procedure. Aflatoxin M(1) was detected in breast milk of 20 out of 91 mothers (22%) in concentrations of 6.96 +/- 0.94 (pg/ml) in rural areas. Aflatoxin M(1) contamination was not present in samples of urban areas. The presence of aflatoxin M(1) was significantly associated with consumption of local milk (beta = 0.71, P < 0.001) and stunted growth in children (beta = -0.31, P < 0.015). These findings emphasize the need for developing strategies to reduce exposure to aflatoxin, possibly involving interventions targeted at reducing contamination of foods.
It is difficult to obtain precise and accurate estimates of the true mycotoxin concentration of a bulk lot when using a mycotoxin-sampling plan that measures the concentration in a small portion of the bulk lot. A mycotoxin-sampling plan is defined by a mycotoxin test procedure and a defined accept/reject limit. A mycotoxin test procedure is a complicated process and generally consists of several steps: (a) a sample is taken from the lot, (b) the sample is ground (comminuted) in a mill to reduce particle size, (c) a subsample is removed from the comminuted sample, and (d) the mycotoxin is extracted from the comminuted subsample and quantified. Even when using accepted test procedures, there is variability associated with each step of the mycotoxin test procedure. Because of this variability, the true mycotoxin concentration in the lot cannot be determined with 100% certainty by measuring the mycotoxin concentration in a sample taken from the lot. The variability for each step of the mycotoxin test procedure, as measured by the variance statistic, is shown to increase with mycotoxin concentration. Sampling is usually the largest source of variability associated with the mycotoxin test procedure. Sampling variability is large because a small percentage of kernels are contaminated and the level of contamination on a single seed can be very large. Methods to reduce sampling, sample preparation, and analytical variability are discussed.
Aflatoxins are potent mycotoxins that cause developmental and immune system suppression, cancer, and death. As a result of regulations intended to reduce human exposure, crop contamination with aflatoxins causes significant economic loss for producers, marketers, and processors of diverse susceptible crops. Aflatoxin contamination occurs when specific fungi in the genus Aspergillus infect crops. Many industries frequently affected by aflatoxin contamination know from experience and anecdote that fluctuations in climate impact the extent of contamination. Climate influences contamination, in part, by direct effects on the causative fungi. As climate shifts, so do the complex communities of aflatoxin-producing fungi. This includes changes in the quantity of aflatoxin-producers in the environment and alterations to fungal community structure. Fluctuations in climate also influence predisposition of hosts to contamination by altering crop development and by affecting insects that create wounds on which aflatoxin-producers proliferate. Aflatoxin contamination is prevalent both in warm humid climates and in irrigated hot deserts. In temperate regions, contamination may be severe during drought. The contamination process is frequently broken down into two phases with the first phase occurring on the developing crop and the second phase affecting the crop after maturation. Rain and temperature influence the phases differently with dry, hot conditions favoring the first and warm, wet conditions favoring the second. Contamination varies with climate both temporally and spatially. Geostatistics and multiple regression analyses have shed light on influences of weather on contamination. Geostatistical analyses have been used to identify recurrent contamination patterns and to match these with environmental variables. In the process environmental conditions with the greatest impact on contamination are identified. Likewise, multiple regression analyses allow ranking of environmental variables based on relative influence on contamination. Understanding the impact of climate may allow development of improved management procedures, better allocation of monitoring efforts, and adjustment of agronomic practices in anticipation of global climate change.
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