Molecular biology of mycotoxin biosynthesis

Sweeney, M. J.; Dobson, Alan D. W.

doi:10.1111/j.1574-6968.1999.tb13614.x

Cited by 144 publications

(71 citation statements)

References 51 publications

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“…These species produce some of the most important mycotoxins, including trichothecenes, aXatoxins, sterigmatocystin, fumonisins, and AAL-toxins [1,23,73]. Extensive research has been devoted to aXatoxins, sterigmatocystin, and trichothecenes, and their biosynthesis is relatively well understood [11,23,39,53].…”

Section: Introductionmentioning

confidence: 99%

Biosynthesis of sphinganine-analog mycotoxins

Zhu

Gerber

et al. 2008

J Ind Microbiol Biotechnol

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Sphinganine-analog mycotoxins (SAMT) are polyketide-derived natural products produced by a number of plant pathogenic fungi and are among the most economically important mycotoxins. The toxins are structurally similar to sphinganine, a key intermediate in the biosynthesis of ceramides and sphingolipids, and competitive inhibitors for ceramide synthase. The inhibition of ceramide and sphingolipid biosynthesis is associated with several fatal diseases in domestic animals and esophageal cancer and neural tube defects in humans. SAMT contains a highly reduced, acyclic polyketide carbon backbone, which is assembled by a single module polyketide synthase. The biosynthesis of SAMT involves a unique polyketide chain-releasing mechanism, in which a pyridoxal 5'-phosphate-dependent enzyme catalyzes the termination, offloading and elongation of the polyketide chain. This leads to the introduction of a new carbon-carbon bond and an amino group to the polyketide chain. The mechanism is fundamentally different from the thioesterase/cyclase-catalyzed polyketide chain releasing found in bacterial and other fungal polyketide biosynthesis. Genetic data suggest that the ketosynthase domain of the polyketide synthase and the chain-releasing enzyme are important for controlling the final product structure. In addition, several post-polyketide modifications have to take place before SAMT become mature toxins.

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Section: Introductionmentioning

confidence: 99%

Biosynthesis of sphinganine-analog mycotoxins

Zhu

Gerber

et al. 2008

J Ind Microbiol Biotechnol

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“…The number of the most commonly occurring species in foods/feeds and indoor environments is estimated to be around 175 [6]. The most toxigenic species belong mainly to three fungi genera: Fusarium, Aspergillus, and Penicillium [7][8][9][10]. These fungi can produce a wide range of mycotoxins differing not only in their chemical structures but also in the mode of toxicological actions.…”

Section: Introductionmentioning

confidence: 99%

Advanced LC–MS-based methods to study the co-occurrence and metabolization of multiple mycotoxins in cereals and cereal-based food

Malachová

Stranska-Zachariasova

Václavíková

et al. 2017

Anal Bioanal Chem

130

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Liquid chromatography (LC) coupled with mass spectrometry (MS) is widely used for the determination of mycotoxins in cereals and cereal-based products. In addition to the regulated mycotoxins, for which official control is required, LC-MS is often used for the screening of a large range of mycotoxins and/or for the identification and characterization of novel metabolites. This review provides insight into the LC-MS methods used for the determination of co-occurring mycotoxins with special emphasis on multiple-analyte applications. The first part of the review is focused on targeted LC-MS approaches using cleanup methods such as solid-phase extraction and immunoaffinity chromatography, as well as on methods based on minimum cleanup (quick, easy, cheap, effective, rugged, and safe; QuEChERS) and dilute and shoot. The second part of the review deals with the untargeted determination of mycotoxins by LC coupled with high-resolution MS, which includes also metabolomics techniques to study the fate of mycotoxins in plants.

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“…This opportunistic pathogen produces a wide range of secondary metabolites, including aflatoxins (AFs). Among them, AFB1 is the most mutagenic and carcinogenic natural compound known (4)(5)(6)(7)(8). Ingestion of food products contaminated with AFs has been associated with hepatotoxicity, teratogenicity, immunosuppression, and liver cancer (6,9).…”

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confidence: 99%

Transcriptome Analysis of Aspergillus flavus Reveals veA -Dependent Regulation of Secondary Metabolite Gene Clusters, Including the Novel Aflavarin Cluster

et al. 2015

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eThe global regulatory veA gene governs development and secondary metabolism in numerous fungal species, including Aspergillus flavus. This is especially relevant since A. flavus infects crops of agricultural importance worldwide, contaminating them with potent mycotoxins. The most well-known are aflatoxins, which are cytotoxic and carcinogenic polyketide compounds. The production of aflatoxins and the expression of genes implicated in the production of these mycotoxins are veA dependent. The genes responsible for the synthesis of aflatoxins are clustered, a signature common for genes involved in fungal secondary metabolism. Studies of the A. flavus genome revealed many gene clusters possibly connected to the synthesis of secondary metabolites. Many of these metabolites are still unknown, or the association between a known metabolite and a particular gene cluster has not yet been established. In the present transcriptome study, we show that veA is necessary for the expression of a large number of genes. Twenty-eight out of the predicted 56 secondary metabolite gene clusters include at least one gene that is differentially expressed depending on presence or absence of veA. One of the clusters under the influence of veA is cluster 39. The absence of veA results in a downregulation of the five genes found within this cluster. Interestingly, our results indicate that the cluster is expressed mainly in sclerotia. Chemical analysis of sclerotial extracts revealed that cluster 39 is responsible for the production of aflavarin.A spergillus flavus is a saprophytic filamentous fungus that is also able to colonize economically important crops such as peanuts, cotton, maize, and other oil seed crops during preharvest or storage. Its most efficient mode of dissemination is the production of airborne conidia. In addition, A. flavus produces resistant structures called sclerotia, which allow this fungus to survive adverse environmental conditions for long periods of time (1-3). This opportunistic pathogen produces a wide range of secondary metabolites, including aflatoxins (AFs). Among them, AFB1 is the most mutagenic and carcinogenic natural compound known (4-8). Ingestion of food products contaminated with AFs has been associated with hepatotoxicity, teratogenicity, immunosuppression, and liver cancer (6, 9). AF contamination also results in a negative impact on the economy in developed countries. In the United States alone A. flavus causes more than a billion dollar in losses per year due to contaminated crops (10). In addition to AFs, A. flavus is known to produce other mycotoxins, including cyclopiazonic acid (CPA), a suppressor of the calcium-dependent ATPase in the sarcoplasmic reticulum, and aflatrem, a tremogenic mycotoxin causative of neurological disorders (11,12).Studies of the A. flavus genome have revealed many gene clusters possibly connected to the synthesis of other secondary metabolites. Specifically, 55 different clusters were predicted based on the presence of genes encoding polyketide synthases (PKSs), non...

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Molecular biology of mycotoxin biosynthesis

Cited by 144 publications

References 51 publications

Biosynthesis of sphinganine-analog mycotoxins

Biosynthesis of sphinganine-analog mycotoxins

Advanced LC–MS-based methods to study the co-occurrence and metabolization of multiple mycotoxins in cereals and cereal-based food

Transcriptome Analysis of Aspergillus flavus Reveals veA -Dependent Regulation of Secondary Metabolite Gene Clusters, Including the Novel Aflavarin Cluster

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