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800 KiB

Open AccessArticle

The Black Aspergillus Species of Maize and Peanuts and Their Potential for Mycotoxin Production

by Edwin R. Palencia, Dorothy M. Hinton and Charles W. Bacon

Toxins 2010, 2(4), 399-416; https://doi.org/10.3390/toxins2040399 - 24 Mar 2010

Cited by 74 | Viewed by 14311

Abstract

The black spored fungi of the subgenera Circumdata,the section Nigri (=Aspergillus niger group) is reviewed relative to their production of mycotoxins and their effects on plants as pathogens. Molecular methods have revealed more than 18 cryptic species, of which several have been [...] Read more.

The black spored fungi of the subgenera Circumdata,the section Nigri (=Aspergillus niger group) is reviewed relative to their production of mycotoxins and their effects on plants as pathogens. Molecular methods have revealed more than 18 cryptic species, of which several have been characterized as potential mycotoxin producers. Others are defined as benign relative to their ability to produce mycotoxins. However, these characterizations are based on in vitro culture and toxins production. Several can produce the ochratoxins that are toxic to livestock, poultry, and humans. The black aspergilli produce rots of grapes, maize, and numerous other fruits and grain and they are generally viewed as post-harvest pathogens. Data are review to suggest that black aspergilli, as so many others, are symptomless endophytes. These fungi and their mycotoxins contaminate several major grains, foodstuffs, and products made from them such as wine, and coffee. Evidence is presented that the black aspergilli are producers of other classes of mycotoxins such as the fumonisins, which are known carcinogenic and known prior investigations as being produced by the Fusarium species. Three species are identified in U.S. maize and peanuts as symptomless endophytes, which suggests the potential for concern as pathogens and as food safety hazards. Full article

(This article belongs to the Special Issue Advances in Mycotoxin Research)

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361 KiB

Open AccessArticle

Development of an Electrochemical Immunosensor for Fumonisins Detection in Foods

by Mohamad Kamal Abdul Kadir and Ibtisam E. Tothill

Toxins 2010, 2(4), 382-398; https://doi.org/10.3390/toxins2040382 - 24 Mar 2010

Cited by 51 | Viewed by 11490

Abstract

An electrochemical affinity sensor for the determination of fumonisins mycotoxins (Fms) using monoclonal antibody modified screen-printed gold electrode with carbon counter and silver-silver chloride pseudo-reference electrode is reported in this work. A direct competitive enzyme-linked immunosorbent assay (ELISA) was initially developed, exhibiting a [...] Read more.

An electrochemical affinity sensor for the determination of fumonisins mycotoxins (Fms) using monoclonal antibody modified screen-printed gold electrode with carbon counter and silver-silver chloride pseudo-reference electrode is reported in this work. A direct competitive enzyme-linked immunosorbent assay (ELISA) was initially developed, exhibiting a detection limit of 100 µg·L^-1for fumonisins. This was then transferred to the surface of a bare gold screen-printed electrode (SPGE) and detection was performed by chronoamperometry, monitoring the reaction of 3,3’,5,5’-Tetramethylbenzidine dihydrochloride (TMB) and hydrogen peroxide (H₂O₂) catalysed by HRP at −100 mV potential vs. onboard Ag-AgCl pseudo-reference electrode. The immunosensor exhibited detection limit of 5 µg·L⁻¹ fumonisins with a dynamic range from 1 µg·L⁻¹–1000 µg·L⁻¹. The sensor also performed well in extracted corn samples. Full article

(This article belongs to the Special Issue Advances in Mycotoxin Research)

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283 KiB

Open AccessArticle

Environmental Factors and Interactions with Mycobiota of Grain and Grapes: Effects on Growth, Deoxynivalenol and Ochratoxin Production by Fusarium culmorum and Aspergillus carbonarius

by Naresh Magan, David Aldred, Russell Hope and David Mitchell

Toxins 2010, 2(3), 353-366; https://doi.org/10.3390/toxins2030353 - 18 Mar 2010

Cited by 47 | Viewed by 11210

Abstract

Mycotoxigenic fungi colonizing food matrices are inevitably competing with a wide range of other resident fungi. The outcomes of these interactions are influenced by the prevailing environmental conditions and the competing species. We have evaluated the competitiveness of F. culmorum and A. carbonarius [...] Read more.

Mycotoxigenic fungi colonizing food matrices are inevitably competing with a wide range of other resident fungi. The outcomes of these interactions are influenced by the prevailing environmental conditions and the competing species. We have evaluated the competitiveness of F. culmorum and A. carbonarius in the grain and grape food chain for their in vitro and in situ dominance in the presence of other fungi, and the effect that such interactions have on colony interactions, growth and deoxynivalenol (DON) and ochratoxin A (OTA) production. The Index of Dominance shows that changes in water activity (a_w) and temperature affect the competitiveness of F. culmorum and A. carbonarius against up to nine different fungi. Growth of both mycotoxigenic species was sometimes inhibited by the presence of other competing fungi. For example, A. niger uniseriate and biseriate species decreased growth of A. carbonarius, while Aureobasidium pullulans and Cladosporium species stimulated growth. Similar changes were observed when F. graminearum was interacting with other grain fungi such as Alternaria alternata, Cladopsorium herbarum and Epicoccum nigrum. The impact on DON and OTA production was very different. For F. culmorum, the presence of other species often inhibited DON production over a range of environmental conditions. For A.carbonarius, on a grape–based medium, the presence of certain species resulted in a significant stimulation of OTA production. However, this was influenced by both temperature and a_w level. This suggests that the final mycotoxin concentrations observed in food matrices may be due to complex interactions between species and the environmental history of the samples analyzed. Full article

(This article belongs to the Special Issue Advances in Mycotoxin Research)

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593 KiB

Open AccessCommunication

Detection of Fumonisin B1 and Ochratoxin A in Grain Products Using Microsphere-Based Fluid Array Immunoassays

by George P. Anderson, Vasudha A. Kowtha and Chris R. Taitt

Toxins 2010, 2(2), 297-309; https://doi.org/10.3390/toxins2020297 - 25 Feb 2010

Cited by 39 | Viewed by 10607

Abstract

Grain products are a staple of diets worldwide and therefore, the ability to accurately and efficiently detect foodborne contaminants such as mycotoxins is of importance to everyone. Here we describe an indirect competitive fluid array fluoroimmunoassay to quantify the mycotoxins, fumonisin B1 and [...] Read more.

Grain products are a staple of diets worldwide and therefore, the ability to accurately and efficiently detect foodborne contaminants such as mycotoxins is of importance to everyone. Here we describe an indirect competitive fluid array fluoroimmunoassay to quantify the mycotoxins, fumonisin B1 and ochratoxin A. Both toxins were immobilized to the surface of microspheres using a variety of intermediate molecules and binding of biotinylated "tracer" antibody tracers determined through flow cytometry using streptavidin-phycoerythrin conjugates and the Luminex100 flow cytometer. Competitive assays were developed where the binding of biotinylated monoclonal antibodies to fumonisin B and ochratoxin A was competitively inhibited by different concentrations of those toxins in solution. Concentrations of fumonisin giving 50% inhibition were 300 pg/mL in buffer, 100 ng/g in spiked oats, and 1 μg/g in spiked cornmeal; analogous concentrations for ochratoxin A were 30 ng/mL in buffer, 30 ng/g in spiked oats, and 10 ng/g in spiked corn. The future challenge will be to expand the number of mycotoxins tested both individually and in multiplexed format using this platform. Full article

(This article belongs to the Special Issue Advances in Mycotoxin Research)

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104 KiB

Open AccessCommunication

Preparation of an In-House Reference Material Containing Fumonisins in Thai Rice and Matrix Extension of the Analytical Method for Japanese Rice

by Norhafniza Awaludin, Reiko Nagata, Tomomi Kawasaki and Masayo Kushiro

Toxins 2009, 1(2), 188-195; https://doi.org/10.3390/toxins1020188 - 8 Dec 2009

Cited by 4 | Viewed by 9407

Abstract

Mycotoxin contamination in rice is less reported, compared to that in wheat or maize, however, some Fusarium fungi occasionally infect rice in the paddy field. Fumonisins are mycotoxins mainly produced by Fusarium verticillioides, which often ruins maize. Rice adherent fungus Gibberella fujikuroi [...] Read more.

Mycotoxin contamination in rice is less reported, compared to that in wheat or maize, however, some Fusarium fungi occasionally infect rice in the paddy field. Fumonisins are mycotoxins mainly produced by Fusarium verticillioides, which often ruins maize. Rice adherent fungus Gibberella fujikuroi is taxonomically near to F. verticillioides, and there are sporadic reports of fumonisin contamination in rice from Asia, Europe and the United States. Therefore, there exists the potential risk of fumonisin contamination in rice as well as the need for the validated analytical method for fumonisins in rice. Although both natural and spiked reference materials are available for some Fusarium mycotoxins in matrices of wheat and maize, there are no reference materials for Fusarium mycotoxins in rice. In this study, we have developed a method for the preparation of a reference material containing fumonisins in Thai rice. A ShakeMaster grinding machine was used for the preparation of a mixed material of blank Thai rice and F. verticillioides-infected Thai rice. The homogeneity of the mixed material was confirmed by one-way analysis of variance, which led this material to serve as an in-house reference material. Using this reference material, several procedures to extract fumonisins from Thai rice were compared. Accordingly, we proved the applicability of an effective extraction procedure for the determination of fumonisins in Japanese rice. Full article

(This article belongs to the Special Issue Advances in Mycotoxin Research)

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613 KiB

Open AccessArticle

Functional Analysis of a Putative Dothistromin Toxin MFS Transporter Gene

by Rosie E. Bradshaw, Zhilun Feng, Arne Schwelm, Yongzhi Yang and Shuguang Zhang

Toxins 2009, 1(2), 173-187; https://doi.org/10.3390/toxins1020173 - 8 Dec 2009

Cited by 9 | Viewed by 10334

Abstract

Dothistromin is a non-host selective toxin produced by the pine needle pathogen Dothistroma septosporum. Dothistromin is not required for pathogenicity, but may have a role in competition and niche protection. To determine how D. septosporum tolerates its own toxin, a putative dothistromin [...] Read more.

Dothistromin is a non-host selective toxin produced by the pine needle pathogen Dothistroma septosporum. Dothistromin is not required for pathogenicity, but may have a role in competition and niche protection. To determine how D. septosporum tolerates its own toxin, a putative dothistromin transporter, DotC, was investigated. Studies with mutants lacking a functional dotC gene, overproducing DotC, or with a DotC-GFP fusion gene, did not provide conclusive evidence of a role in dothistromin efflux. The mutants revealed a major effect of DotC on dothistromin biosynthesis but were resistant to exogenous dothistromin. Intracellular localization studies suggest that compartmentalization may be important for dothistromin tolerance. Full article

(This article belongs to the Special Issue Advances in Mycotoxin Research)

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Review

Jump to: Research

128 KiB

Open AccessReview

Discovery and Characterization of Proteins Associated with Aflatoxin-Resistance: Evaluating Their Potential as Breeding Markers

by Robert L. Brown, Zhi-Yuan Chen, Marilyn Warburton, Meng Luo, Abebe Menkir, Ahmad Fakhoury and Deepak Bhatnagar

Toxins 2010, 2(4), 919-933; https://doi.org/10.3390/toxins2040919 - 26 Apr 2010

Cited by 29 | Viewed by 10806

Abstract

Host resistance has become a viable approach to eliminating aflatoxin contamination of maize since the discovery of several maize lines with natural resistance. However, to derive commercial benefit from this resistance and develop lines that can aid growers, markers need to be identified [...] Read more.

Host resistance has become a viable approach to eliminating aflatoxin contamination of maize since the discovery of several maize lines with natural resistance. However, to derive commercial benefit from this resistance and develop lines that can aid growers, markers need to be identified to facilitate the transfer of resistance into commercially useful genetic backgrounds without transfer of unwanted traits. To accomplish this, research efforts have focused on the identification of kernel resistance-associated proteins (RAPs) including the employment of comparative proteomics to investigate closely-related maize lines that vary in aflatoxin accumulation. RAPs have been identified and several further characterized through physiological and biochemical investigations to determine their causal role in resistance and, therefore, their suitability as breeding markers. Three RAPs, a 14 kDa trypsin inhibitor, pathogenesis-related protein 10 and glyoxalase I are being investigated using RNAi gene silencing and plant transformation. Several resistant lines have been subjected to QTL mapping to identify loci associated with the aflatoxin-resistance phenotype. Results of proteome and characterization studies are discussed. Full article

(This article belongs to the Special Issue Advances in Mycotoxin Research)

380 KiB

Open AccessReview

Biosynthesis and Toxicological Effects of Patulin

by Olivier Puel, Pierre Galtier and Isabelle P. Oswald

Toxins 2010, 2(4), 613-631; https://doi.org/10.3390/toxins2040613 - 5 Apr 2010

Cited by 454 | Viewed by 32594

Abstract

Patulin is a toxic chemical contaminant produced by several species of mold, especially within Aspergillus, Penicillium and Byssochlamys. It is the most common mycotoxin found in apples and apple-derived products such as juice, cider, compotes and other food intended for young [...] Read more.

Patulin is a toxic chemical contaminant produced by several species of mold, especially within Aspergillus, Penicillium and Byssochlamys. It is the most common mycotoxin found in apples and apple-derived products such as juice, cider, compotes and other food intended for young children. Exposure to this mycotoxin is associated with immunological, neurological and gastrointestinal outcomes. Assessment of the health risks due to patulin consumption by humans has led many countries to regulate the quantity in food. A full understanding of the molecular genetics of patulin biosynthesis is incomplete, unlike other regulated mycotoxins (aflatoxins, trichothecenes and fumonisins), although the chemical structures of patulin precursors are now known. The biosynthetic pathway consists of approximately 10 steps, as suggested by biochemical studies. Recently, a cluster of 15 genes involved in patulin biosynthesis was reported, containing characterized enzymes, a regulation factor and transporter genes. This review includes information on the current understanding of the mechanisms of patulin toxinogenesis and summarizes its toxicological effects. Full article

(This article belongs to the Special Issue Advances in Mycotoxin Research)

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522 KiB

Open AccessReview

Real and Perceived Risks for Mycotoxin Contamination in Foods and Feeds: Challenges for Food Safety Control

by Dragan R. Milićević, Marija Škrinjar and Tatjana Baltić

Toxins 2010, 2(4), 572-592; https://doi.org/10.3390/toxins2040572 - 1 Apr 2010

Cited by 224 | Viewed by 19972

Abstract

Mycotoxins are toxic compounds, produced by the secondary metabolism of toxigenic moulds in the Aspergillus, Alternaria, Claviceps, Fusarium, Penicillium and Stachybotrys genera occurring in food and feed commodities both pre- and post-harvest. Adverse human health effects from the consumption [...] Read more.

Mycotoxins are toxic compounds, produced by the secondary metabolism of toxigenic moulds in the Aspergillus, Alternaria, Claviceps, Fusarium, Penicillium and Stachybotrys genera occurring in food and feed commodities both pre- and post-harvest. Adverse human health effects from the consumption of mycotoxins have occurred for many centuries. When ingested, mycotoxins may cause a mycotoxicosis which can result in an acute or chronic disease episode. Chronic conditions have a much greater impact, numerically, on human health in general, and induce diverse and powerful toxic effects in test systems: some are carcinogenic, mutagenic, teratogenic, estrogenic, hemorrhagic, immunotoxic, nephrotoxic, hepatotoxic, dermotoxic and neurotoxic. Although mycotoxin contamination of agricultural products still occurs in the developed world, the application of modern agricultural practices and the presence of a legislatively regulated food processing and marketing system have greatly reduced mycotoxin exposure in these populations. However, in developing countries, where climatic and crop storage conditions are frequently conducive to fungal growth and mycotoxin production, much of the population relies on subsistence farming or on unregulated local markets. Therefore both producers and governmental control authorities are directing their efforts toward the implementation of a correct and reliable evaluation of the real status of contamination of a lot of food commodity and, consequently, of the impact of mycotoxins on human and animal health. Full article

(This article belongs to the Special Issue Advances in Mycotoxin Research)

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349 KiB

Open AccessReview

Role of the Osmotic Stress Regulatory Pathway in Morphogenesis and Secondary Metabolism in Filamentous Fungi

by Rocio Duran, Jeffrey W. Cary and Ana M. Calvo

Toxins 2010, 2(4), 367-381; https://doi.org/10.3390/toxins2040367 - 24 Mar 2010

Cited by 112 | Viewed by 15664

Abstract

Environmental stimuli trigger an adaptative cellular response to optimize the probability of survival and proliferation. In eukaryotic organisms from mammals to fungi osmotic stress, mainly through the action of the high osmolarity glycerol (HOG) pathway, leads to a response necessary for adapting and [...] Read more.

Environmental stimuli trigger an adaptative cellular response to optimize the probability of survival and proliferation. In eukaryotic organisms from mammals to fungi osmotic stress, mainly through the action of the high osmolarity glycerol (HOG) pathway, leads to a response necessary for adapting and surviving hyperosmotic environments. In this review we show that the osmoadaptative response is conserved but not identical in different fungi. The osmoadaptative response system is also intimately linked to morphogenesis in filamentous fungi, including mycotoxin producers. Previous studies indicate that the response to osmotic stress is also coupled to the biosynthesis of natural products, including mycotoxins. Full article

(This article belongs to the Special Issue Advances in Mycotoxin Research)

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908 KiB

Open AccessReview

Mycotoxin Contamination of Beverages: Occurrence of Patulin in Apple Juice and Ochratoxin A in Coffee, Beer and Wine and Their Control Methods

by Kasa R. N. Reddy, Hamed K. Abbas, Craig A. Abel, Wayne Thomas Shier and Baharuddin Salleh

Toxins 2010, 2(2), 229-261; https://doi.org/10.3390/toxins2020229 - 2 Feb 2010

Cited by 14 | Viewed by 11349 | Retraction

Abstract

It has been brought to our attention by a member of our Editorial Board that substantial portions of this review article have been copied verbatim from earlier publications without credit. After comparing the present paper and the other sources we have determined that [...] Read more.

It has been brought to our attention by a member of our Editorial Board that substantial portions of this review article have been copied verbatim from earlier publications without credit. After comparing the present paper and the other sources we have determined that indeed this manuscript clearly violates our policy on originality of all material submitted for publication and the generally accepted ethics of scientific publication. Consequently, the Editorial Team and Publisher have determined that it should be retracted. We apologize for any inconvenience this may cause. Full article

(This article belongs to the Special Issue Advances in Mycotoxin Research)

309 KiB

Open AccessReview

Fluorescence Polarization Immunoassay of Mycotoxins: A Review

by Chris Maragos

Toxins 2009, 1(2), 196-207; https://doi.org/10.3390/toxins1020196 - 10 Dec 2009

Cited by 56 | Viewed by 18104

Abstract

Immunoassays are routinely used in the screening of commodities and foods for fungal toxins (mycotoxins). Demands to increase speed and lower costs have lead to continued improvements in such assays. Because many reported mycotoxins are low molecular weight (below 1 kDa), immunoassays for [...] Read more.

Immunoassays are routinely used in the screening of commodities and foods for fungal toxins (mycotoxins). Demands to increase speed and lower costs have lead to continued improvements in such assays. Because many reported mycotoxins are low molecular weight (below 1 kDa), immunoassays for their detection have generally been constructed in competitive heterogeneous formats. An exception is fluorescence polarization immunoassay (FPIA), a homogeneous format that does not require the separation of bound and free labels (tracer). The potential for rapid, solution phase, immunoassays has been realized in the development of FPIA for many of the major groups of mycotoxins, including aflatoxins, fumonisins, group B trichothecenes (primarily deoxynivalenol), ochratoxin A, and zearalenone. This review describes the basic principles of FPIA and summarizes recent research in this area with regard to mycotoxins. Full article

(This article belongs to the Special Issue Advances in Mycotoxin Research)

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