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1.
Chem Biol Interact ; 347: 109614, 2021 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-34364835

RESUMO

Ochratoxin A (OTA), an important fungal metabolite in foods and feeds has been shown to induce oxidative stress and cellular injuries to human and animal subjects. This study was designed to investigate the mode of action of a biological modifier Trichosporon mycotoxinivorans (TM), against OTA-mediated oxidative stress and tissue toxicity on broiler chickens. The birds were offered diets supplemented with OTA (0.15 and 0.3 mg/kg feed) and/or TM (0.5, 1.0 g/kg) for 42 days of age, and blood and tissue samples were collected to examine the oxidative stress, biochemical and histopathological parameters. Dietary OTA at all the tested levels induced the hepatic and renal tissue injury as indicated by significant decreased total antioxidant capacity in these organs along with significant decreased (p ≤ 0.05) serum concentrations of total proteins and albumin. The serum concentrations of alanine aminotransferase (ALT) and urea were significantly increased, and these observations were further supported by degenerative changes and increased relative weights of liver and kidneys. The dietary supplementation of TM at both tested levels relieved the detrimental impact of 0.15 and 0.3 mg OTA/kg on the studied parameters. The results of the study demonstrated that dietary TM significantly protects broiler chickens by reducing OTA-induced oxidative damage and tissue injury.


Assuntos
Basidiomycota/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/dietoterapia , Suplementos Nutricionais/microbiologia , Nefropatias/dietoterapia , Micotoxinas/toxicidade , Ocratoxinas/toxicidade , Animais , Aspergillus ochraceus , Galinhas , Rim/efeitos dos fármacos , Rim/patologia , Fígado/efeitos dos fármacos , Fígado/patologia , Micotoxinas/metabolismo , Ocratoxinas/metabolismo , Tamanho do Órgão/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos
2.
PLoS One ; 16(7): e0254541, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34320014

RESUMO

Corynespora cassiicola, a fungal plant pathogen with a large host range, causes important damages in rubber tree (Hevea brasiliensis), in Asia and Africa. A small secreted protein named cassiicolin was previously identified as a necrotrophic effector required for the virulence of C. cassiicola in specific rubber tree clones. The objective of this study was to decipher the cassiicolin-mediated molecular mechanisms involved in this compatible interaction. We comparatively analyzed the RNA-Seq transcriptomic profiles of leaves treated or not with the purified cassiicolin Cas1, in two rubber clones: PB260 (susceptible) and RRIM600 (tolerant). The reads were mapped against a synthetic transcriptome composed of all available transcriptomic references from the two clones. Genes differentially expressed in response to cassiicolin Cas1 were identified, in each clone, at two different time-points. After de novo annotation of the synthetic transcriptome, we analyzed GO enrichment of the differentially expressed genes in order to elucidate the main functional pathways impacted by cassiicolin. Cassiicolin induced qualitatively similar transcriptional modifications in both the susceptible and the tolerant clones, with a strong negative impact on photosynthesis, and the activation of defense responses via redox signaling, production of pathogenesis-related protein, or activation of the secondary metabolism. In the tolerant clone, transcriptional reprogramming occurred earlier but remained moderate. By contrast, the susceptible clone displayed a late but huge transcriptional burst, characterized by massive induction of phosphorylation events and all the features of a hypersensitive response. These results confirm that cassiicolin Cas1 is a necrotrophic effector triggering a hypersensitive response in susceptible rubber clones, in agreement with the necrotrophic-effector-triggered susceptibility model.


Assuntos
Ascomicetos/metabolismo , Proteínas Fúngicas/farmacologia , Hevea/genética , Micotoxinas/farmacologia , Transcriptoma/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Hevea/metabolismo , Hevea/microbiologia , Micotoxinas/genética , Micotoxinas/metabolismo , Fosforilação , Fotossíntese/genética , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Imunidade Vegetal/genética , Folhas de Planta/genética , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Análise de Componente Principal , RNA de Plantas/química , RNA de Plantas/genética , RNA de Plantas/metabolismo , Transdução de Sinais/genética , Regulação para Cima/efeitos dos fármacos
3.
Toxins (Basel) ; 13(5)2021 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-34069221

RESUMO

Fusarium head blight (FHB) causes wheat yield loss and mycotoxin (deoxynivalenol, DON) accumulation in wheat kernel. Developing wheat cultivars with overall resistance to both FHB spread within a spike and DON accumulation in kernels is crucial for ensuring food security and food safety. Here, two relatively novel inoculation methods, bilateral floret inoculation (BFI) and basal rachis internode injection (BRII), were simultaneously employed to evaluate disease severity and DON content in kernels in a segregating population of recombinant inbred lines (RILs) developed from Ning 7840 (carrying Fhb1) and Clark (without Fhb1). Under both inoculation methods, four contrasting combinations of disease severity and DON content were identified: high severity/high DON (HSHD), high severity/low DON (HSLD), low severity/high DON (LSHD) and low severity/low DON (LSLD). Unexpectedly, the BRII method clearly indicated that disease severity was not necessarily relevant to DON concentration. The effects of Fhb1 on disease severity, and on DON concentrations, agreed very well across the two methods. Several lines carrying Fhb1 showed extremely higher severity and (or) DON content under both inoculation methods. The "Mahalanobis distance" (MD) method was used to rate overall resistance of a line by inclusion of both disease severity and DON content over both methods to select LSLD lines.


Assuntos
Fusarium/patogenicidade , Doenças das Plantas/microbiologia , Tricotecenos/metabolismo , Triticum/microbiologia , Micotoxinas/metabolismo
4.
World J Microbiol Biotechnol ; 37(7): 112, 2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34081209

RESUMO

Grapevine cultivars are distributed worldwide, nevertheless the fermentation of its grape berries renders distinct wine products that are highly associated to the local fungal community. Despite the symbiotic association between wine and the fungal metabolism, impacting both the terroir and mycotoxin production, few studies have explored the vineyard ecosystem fungal community using both molecular marker sequencing and mycotoxin production assessment. In this study, we investigated the fungal community of three grapevine cultivars (Vitis vinifera L.) in two tropical vineyards. Illumina MiSeq sequencing was performed on two biocompartments: grape berries (GB) and grapevine soil (GS); yielding a total of 578,495 fungal internal transcribed spacer 1 reads, which were used for taxonomic classification. GB and GS fungal communities were mainly constituted by Ascomycota phylum. GS harbors a significant richer and more diverse fungal community than GB. Among GB samples, Syrah grape berries exclusively shared fungal community included wine-associated yeasts (e.g. Saccharomycopsis vini) that may play key roles in wine terroir. Mycotoxin production assessment revealed the high potential of Aspergillus section Flavi and Penicillium section Citrina isolates to produce aflatoxin B1-B2 and citrinin, respectively. This is the first study to employ next-generation sequencing to investigate vineyard associated fungal community in Brazil. Our findings provide valuable insights on the available tools for fungal ecology assessment applied to food products emphasizing the coexistence between classical and molecular tools.


Assuntos
DNA Espaçador Ribossômico/genética , Fungos/classificação , Micotoxinas/metabolismo , Análise de Sequência de DNA/métodos , Vitis/microbiologia , Brasil , DNA Fúngico/genética , Fazendas , Fungos/genética , Fungos/isolamento & purificação , Fungos/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Filogenia , Microbiologia do Solo , Clima Tropical
5.
Microbiol Res ; 249: 126770, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33932742

RESUMO

Trichoderma species are well known for producing various secondary metabolites in response to different fungal pathogens. This paper reports the effects of the metabolites produced during one-day cultivation of Trichoderma harzianum on the growth and development of the popular pathogen Fusarium culmorum. Inhibition of the growth of the pathogen and production of secondary metabolites including zearalenone was observed on Petri dishes. The presence of proteins such as cytochrome c oxidase subunit 4, glutathione-independent glyoxalase HSP31, and putative peroxiredoxin pmp20 in the extract-treated culture indicated oxidative stress, which was confirmed by the presence of a higher amount of catalase and dismutase in the later hours of the culture. A larger amount of enolase and glyceraldehyde 3-phosphate dehydrogenase resulted in faster growth, and the overexpression of stress protein and Woronin body major protein indicated the activation of defense mechanisms. In addition, a cardinal reduction in major mycotoxin production was noted.


Assuntos
Antibiose , Proteínas Fúngicas/metabolismo , Fusarium/crescimento & desenvolvimento , Fusarium/metabolismo , Hypocreales/metabolismo , Meios de Cultura , Metaboloma , Micotoxinas/metabolismo , Estresse Oxidativo , Pigmentos Biológicos/metabolismo , Proteoma , Metabolismo Secundário , Zearalenona/metabolismo
6.
Int J Mol Sci ; 22(8)2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33920773

RESUMO

Rice false smut is a fungal disease distributed worldwide and caused by Ustilaginoidea virens. In this study, we identified a putative ester cyclase (named as UvEC1) as being significantly upregulated during U. virens infection. UvEC1 contained a SnoaL-like polyketide cyclase domain, but the functions of ketone cyclases such as SnoaL in plant fungal pathogens remain unclear. Deletion of UvEC1 caused defects in vegetative growth and conidiation. UvEC1 was also required for response to hyperosmotic and oxidative stresses and for maintenance of cell wall integrity. Importantly, ΔUvEC1 mutants exhibited reduced virulence. We performed a tandem mass tag (TMT)-based quantitative proteomic analysis to identify differentially accumulating proteins (DAPs) between the ΔUvEC1-1 mutant and the wild-type isolate HWD-2. Proteomics data revealed that UvEC1 has a variety of effects on metabolism, protein localization, catalytic activity, binding, toxin biosynthesis and the spliceosome. Taken together, our findings suggest that UvEC1 is critical for the development and virulence of U. virens.


Assuntos
Proteínas Fúngicas/metabolismo , Hypocreales/metabolismo , Hypocreales/patogenicidade , Isomerases/metabolismo , Oryza/microbiologia , Doenças das Plantas/microbiologia , Proteômica , Sequência de Aminoácidos , Proteínas Fúngicas/química , Deleção de Genes , Genoma Fúngico , Hypocreales/genética , Hypocreales/crescimento & desenvolvimento , Isomerases/química , Micotoxinas/genética , Micotoxinas/metabolismo , Proteoma/metabolismo , Spliceossomos/metabolismo , Esporos Fúngicos/metabolismo , Estresse Fisiológico , Frações Subcelulares/metabolismo
7.
Toxins (Basel) ; 13(3)2021 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-33801997

RESUMO

Seeking useful biological agents for mycotoxin detoxification has achieved success in the last twenty years thanks to the participation of many multidisciplinary teams. We have recently witnessed discoveries in the fields of bacterial genetics (inclusive of next-generation sequencing), protein encoding, and bioinformatics that have helped to shape the latest perception of how microorganisms/mycotoxins/environmental factors intertwine and interact, so the road is opened for new breakthroughs. Analysis of literature data related to the biological control of mycotoxins indicates the ability of yeast, bacteria, fungi and enzymes to degrade or adsorb mycotoxins, which increases the safety and quality of susceptible crops, animal feed and, ultimately, food of animal origin (milk, meat and eggs) by preventing the presence of residues. Microbial detoxification (transformation and adsorption) is becoming a trustworthy strategy that leaves no or less toxic compounds and contributes to food security. This review summarizes the data and highlights the importance and prospects of these methods.


Assuntos
Ração Animal/microbiologia , Proteção de Cultivos , Produtos Agrícolas/microbiologia , Contaminação de Alimentos/prevenção & controle , Fungos/metabolismo , Micotoxinas/metabolismo , Controle Biológico de Vetores , Adsorção , Animais , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimento , Abastecimento de Alimentos , Humanos , Inativação Metabólica , Micotoxinas/toxicidade , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/microbiologia
8.
Toxins (Basel) ; 13(3)2021 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-33806727

RESUMO

Sixty-four corn silages were characterized for chemicals, bacterial community, and concentrations of several fungal metabolites. Silages were grouped in five clusters, based on detected mycotoxins, and they were characterized for being contaminated by (1) low levels of Aspergillus- and Penicillium-mycotoxins; (2) low levels of fumonisins and other Fusarium-mycotoxins; (3) high levels of Aspergillus-mycotoxins; (4) high levels of non-regulated Fusarium-mycotoxins; (5) high levels of fumonisins and their metabolites. Altersetin was detected in clusters 1, 3, and 5. Rugulusovin or brevianamide F were detected in several samples, with the highest concentration in cluster 3. Emodin was detected in more than 50.0% of samples of clusters 1, 3 and 5, respectively. Kojic acid occurred mainly in clusters 1 and 2 at very low concentrations. Regarding Fusarium mycotoxins, high occurrences were observed for FB3, FB4, FA1, whereas the average concentrations of FB6 and FA2 were lower than 12.4 µg/kg dry matter. Emerging Fusarium-produced mycotoxins, such as siccanol, moniliformin, equisetin, epiequisetin and bikaverin were detected in the majority of analyzed corn silages. Pestalotin, oxaline, phenopirrozin and questiomycin A were detected at high incidences. Concluding, this work highlighted that corn silages could be contaminated by a high number of regulated and emerging mycotoxins.


Assuntos
Bactérias/metabolismo , Fermentação , Microbiologia de Alimentos , Armazenamento de Alimentos , Fungos/metabolismo , Micotoxinas/metabolismo , Zea mays/microbiologia , Microbiota , Metabolismo Secundário
9.
Toxins (Basel) ; 13(3)2021 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-33801544

RESUMO

The removal of mycotoxins from contaminated feed using lactic acid bacteria (LAB) has been proposed as an inexpensive, safe, and promising mycotoxin decontamination strategy. In this study, viable and heat-inactivated L. acidophilus CIP 76.13T and L. delbrueckii subsp. bulgaricus CIP 101027T cells were investigated for their ability to remove aflatoxin B1 (AFB1), ochratoxin A (OTA), zearalenone (ZEA), and deoxynivalenol (DON) from MRS medium and PBS buffer over a 24 h period at 37 °C. LAB decontamination activity was also assessed in a ZEA-contaminated liquid feed (LF). Residual mycotoxin concentrations were determined by UHPLC-FLD/DAD analysis. In PBS, viable L. acidophilus CIP 76.13T and L. delbrueckii subsp. bulgaricus CIP 101027T cells removed up to 57% and 30% of ZEA and DON, respectively, while AFB1 and OTA reductions were lower than 15%. In MRS, 28% and 33% of ZEA and AFB1 were removed, respectively; OTA and DON reductions were small (≤15%). Regardless of the medium, heat-inactivated cells produced significantly lower mycotoxin reductions than those obtained with viable cells. An adsorption mechanism was suggested to explain the reductions in AFB1 and OTA, while biodegradation could be responsible for the removal of ZEA and DON. Both viable LAB strains reduced ZEA by 23% in contaminated LF after 48 h of incubation. These findings suggest that LAB strains of L. acidophilus CIP 76.13T and L. delbrueckii subsp. bulgaricus CIP 101027T may be applied in the feed industry to reduce mycotoxin contamination.


Assuntos
Ração Animal/microbiologia , Microbiologia de Alimentos , Fungos/metabolismo , Lactobacillus acidophilus/metabolismo , Lactobacillus delbrueckii/metabolismo , Micotoxinas/metabolismo , Adsorção , Animais , Fungos/crescimento & desenvolvimento , Humanos , Inativação Metabólica , Lactobacillus acidophilus/isolamento & purificação , Lactobacillus delbrueckii/isolamento & purificação , Viabilidade Microbiana , Sus scrofa , Urina/microbiologia
10.
Toxins (Basel) ; 13(4)2021 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-33917246

RESUMO

Ageritin is a specific ribonuclease, extracted from the edible mushroom Cyclocybe aegerita (synonym Agrocybe aegerita), which cleaves a single phosphodiester bond located within the universally conserved alpha-sarcin loop (SRL) of 23-28S rRNAs. This cleavage leads to the inhibition of protein biosynthesis, followed by cellular death through apoptosis. The structural and enzymatic properties show that Ageritin is the prototype of a novel specific ribonucleases family named 'ribotoxin-like proteins', recently found in fruiting bodies of other edible basidiomycetes mushrooms (e.g., Ostreatin from Pleurotus ostreatus, Edulitins from Boletus edulis, and Gambositin from Calocybe gambosa). Although the putative role of this toxin, present in high amount in fruiting body (>2.5 mg per 100 g) of C. aegerita, is unknown, its antifungal and insecticidal actions strongly support a role in defense mechanisms. Thus, in this review, we focus on structural, biological, antipathogenic, and enzymatic characteristics of this ribotoxin-like protein. We also highlight its biological relevance and potential biotechnological applications in agriculture as a bio-pesticide and in biomedicine as a therapeutic and diagnostic agent.


Assuntos
Agaricales/enzimologia , Carpóforos/enzimologia , Micotoxinas/metabolismo , Ribonucleases/metabolismo , Agaricales/genética , Animais , Antifúngicos/farmacologia , Antineoplásicos/farmacologia , Antivirais/farmacologia , Agentes de Controle Biológico/farmacologia , Carpóforos/genética , Humanos , Micotoxinas/genética , Micotoxinas/farmacologia , Filogenia , Conformação Proteica , Ribonucleases/genética , Ribonucleases/farmacologia , Relação Estrutura-Atividade
11.
Toxins (Basel) ; 13(4)2021 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-33917534

RESUMO

Fungal phytotoxic secondary metabolites are poisonous substances to plants produced by fungi through naturally occurring biochemical reactions. These metabolites exhibit a high level of diversity in their properties, such as structures, phytotoxic activities, and modes of toxicity. They are mainly isolated from phytopathogenic fungal species in the genera of Alternaria, Botrytis, Colletotrichum, Fusarium, Helminthosporium, and Phoma. Phytotoxins are either host specific or non-host specific phytotoxins. Up to now, at least 545 fungal phytotoxic secondary metabolites, including 207 polyketides, 46 phenols and phenolic acids, 135 terpenoids, 146 nitrogen-containing metabolites, and 11 others, have been reported. Among them, aromatic polyketides and sesquiterpenoids are the main phytotoxic compounds. This review summarizes their chemical structures, sources, and phytotoxic activities. We also discuss their phytotoxic mechanisms and structure-activity relationships to lay the foundation for the future development and application of these promising metabolites as herbicides.


Assuntos
Fungos/metabolismo , Herbicidas/toxicidade , Micotoxinas/toxicidade , Plantas/efeitos dos fármacos , Animais , Herbicidas/química , Herbicidas/metabolismo , Humanos , Estrutura Molecular , Micotoxinas/química , Micotoxinas/metabolismo , Metabolismo Secundário , Relação Estrutura-Atividade
12.
Toxins (Basel) ; 13(4)2021 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-33918546

RESUMO

Fusarium kuroshium is the fungal symbiont associated with the ambrosia beetle Euwallacea kuroshio, a plague complex that attacks avocado, among other hosts, causing a disease named Fusarium dieback (FD). However, the contribution of F. kuroshium to the establishment of this disease remains unknown. To advance the understanding of F. kuroshium pathogenicity, we profiled its exo-metabolome through metabolomics tools based on accurate mass spectrometry. We found that F. kuroshium can produce several key metabolites with phytotoxicity properties and other compounds with unknown functions. Among the metabolites identified in the fungal exo-metabolome, fusaric acid (FA) was further studied due to its phytotoxicity and relevance as a virulence factor. We tested both FA and organic extracts from F. kuroshium at various dilutions in avocado foliar tissue and found that they caused necrosis and chlorosis, resembling symptoms similar to those observed in FD. This study reports for first-time insights regarding F. kuroshium associated with its virulence, which could lead to the potential development of diagnostic and management tools of FD disease and provides a basis for understanding the interaction of F. kuroshium with its host plants.


Assuntos
Fusarium/metabolismo , Metaboloma , Micotoxinas/metabolismo , Persea/microbiologia , Doenças das Plantas/microbiologia , Folhas de Planta/microbiologia , Cromatografia de Fase Reversa , Fusarium/patogenicidade , Interações Hospedeiro-Patógeno , Metabolômica , Persea/crescimento & desenvolvimento , Persea/metabolismo , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem , Virulência
13.
World J Microbiol Biotechnol ; 37(5): 78, 2021 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-33797632

RESUMO

Fusarium verticillioides is a prolific producer of useful secondary metabolites such as naphthoquinone pigments, monoterpenes, and sesquiterpenes, as well as the harmful mycotoxins fumonisins. A strategy to increase their production includes creating a proper nutritional environment that enables the fungus to produce the compounds of interest. The aim of the present work was to study the effect of different carbon sources (glucose, fructose, xylose, sucrose, and lactose) on secondary metabolites biosynthesis in F. verticillioides submerged cultures. The production of volatile terpenes was evaluated through gas chromatography coupled to mass spectrometry. The quantification and identification of pigments was conducted using a UV/VIS spectrophotometer and NMR spectrometer, respectively. The quantification of fumonisin B1 and fumonisin B2 was performed by high-performance liquid chromatography. Our results showed that the biosynthesis of naphthoquinone pigments, monoterpenes, and sesquiterpenes was highest in cultures with fructose (13.00 ± 0.71 mmol/g), lactose [564.52 × 10-11 ± 11.50 × 10-11 µg/g dry weight (DW)], and xylose (54.41 × 10-11 ± 1.55 × 10-11 µg/g DW), respectively, with fumonisin being absent or present in trace amounts in the presence of these carbon sources. The highest biosynthesis of fumonisins occurred in sucrose-containing medium (fumonisin B1: 7.85 × 103 ± 0.25 × 103 µg/g DW and fumonisin B2: 0.38 × 103 ± 0.03 × 103 µg/g DW). These results are encouraging since we were able to enhance the production of useful fungal metabolites without co-production with harmful mycotoxins by controlling the carbon source provided in the culture medium.


Assuntos
Carbono/metabolismo , Fusarium/metabolismo , Micotoxinas/metabolismo , Pigmentos Biológicos/biossíntese , Terpenos/metabolismo , Cromatografia Líquida de Alta Pressão , Meios de Cultura , Fumonisinas/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Monoterpenos/metabolismo , Naftoquinonas/metabolismo , Metabolismo Secundário , Sesquiterpenos/metabolismo , Terpenos/química
14.
Artigo em Inglês | MEDLINE | ID: mdl-33861173

RESUMO

The occurrence of secondary metabolites and co-contaminants in dairy cow feed samples (n = 115), concentrate, roughage, and mixed feed, collected from Ratchaburi and Kanjanaburi provinces, Thailand, between August 2018 and March 2019 were investigated using LC-MS/MS based multi-toxin method. A total of 113 metabolites were found in the samples. Fungal metabolites were the predominant compounds, followed by plant metabolites. Among major mycotoxins, zearalenone and fumonisins were most frequently detected in concentrate and mixed feed samples, while deoxynivalenol and aflatoxin B1 were found at the frequency lower than 50%. Other metabolites, produced by Aspergillus, Fusarium, Penicillium, and Alternaria species, occurred in the samples. Flavoglaucin, 3-nitropropionic acid, averufin, and sterigmatocystin were the most prevalent Aspergillus metabolites. Common Fusarium metabolites occurring in the samples included moniliformin, beauvericin, and enniatins. For Penicillium metabolites, mycophenolic acid, questiomycin A, quinolactacin A, oxaline, citrinin, and dihydrocitrinone were frequently detected. The toxic Alternaria metabolites, alternariol, and alternariol monomethyl ether showed the high incidence in the samples. Plant metabolites were commonly found, mainly cyanogenic compounds and isoflavones, from cassava and soybean meal used as feed ingredients. Overall, 96.6% of feed samples contained at least two metabolites, in a range from 2 to 69. According to co-contamination of mycotoxins found in feed samples, zearalenone were mostly found in combination with fumonisin B1, deoxynivalenol, and aflatoxin B1. Fumonisin B1 co-occurred with aflatoxin B1 and deoxynivalenol. The mixtures of deoxynivalenol and aflatoxin B1, and of zearalenone, fumonisin B1 and deoxynivalenol were also found. Due to known individual toxicity of fungal and plant metabolites and possible additive or synergistic toxic effects of multi-mycotoxins, the occurrence of these metabolites and co-contaminants should be monitored continuously to ensure food safety through the dairy supply chain.


Assuntos
Ração Animal/análise , Aditivos Alimentares/análise , Contaminação de Alimentos/análise , Micotoxinas/análise , Alternaria/metabolismo , Animais , Bovinos , Aditivos Alimentares/metabolismo , Inocuidade dos Alimentos , Fumonisinas/química , Fusarium/metabolismo , Humanos , Metaboloma , Micotoxinas/metabolismo , Penicillium/metabolismo , Metabolismo Secundário , Espectrometria de Massas em Tandem , Tailândia , Tricotecenos/química , Zearalenona/química
15.
Int J Food Microbiol ; 346: 109161, 2021 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-33773354

RESUMO

Fusarium Head Blight (FHB) is a very important fungal disease that affects small grain cereals worldwide. This disease not only causes yield loses but also crops contamination with mycotoxins such as deoxynivalenol (DON) and nivalenol (NIV). Species within the Fusarium graminearum species complex have been described as the main causal agents of this disease, however lately there have been few reports of Fusarium cerealis causing the disease in wheat and barley in different parts of the world. This study evaluated the aggressiveness of F. cerealis to durum wheat cultivars and also mycotoxin production in planta. Moreover, the mycotoxin profile of F. cerealis strains was characterized molecularly and chemically. All durum wheat cultivars showed typical FHB symptoms but the disease severity varied among them in levels up to 66%. In addition, seventeen different compounds were detected in the infected heads including DON, NIV and nivalenol-3-ß-d-glucose (NIV3G). NIV was detected in all cultivars and was the most produced mycotoxin with levels ranging from 1.04 to 6.8 mg/kg. On the other hand, the molecular analysis of F. cerealis strains showed that all of them possessed NIV genotype while the chemical assessment showed that the strains were able to produce not only this toxin in vitro but also DON, zearalenone and other twenty-one secondary metabolites. The increasing incidence of F. cerealis and the possible contamination of crops with the mycotoxins that it produces are of great concern for food security and world cereal trade since it has been reported that NIV is more toxic for humans and animals than DON.


Assuntos
Fusarium/metabolismo , Micotoxinas/metabolismo , Doenças das Plantas/microbiologia , Triticum/microbiologia , Grão Comestível/microbiologia , Contaminação de Alimentos/análise , Fusarium/genética , Genótipo , Hordeum/química , Hordeum/microbiologia , Tricotecenos/análise , Tricotecenos/metabolismo , Triticum/química , Zearalenona/análise , Zearalenona/metabolismo
16.
Food Microbiol ; 97: 103760, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33653530

RESUMO

The global challenge to prevent fungal spoilage and mycotoxin contamination on foods and feeds require the development of new antifungal strategies. Filamentous fungi encode diverse antifungal proteins (AFPs), which offer a great potential for the control of contaminant fungi. In this study, four AFPs from Penicillium digitatum (PdAfpB) and Penicillium expansum (PeAfpA, PeAfpB and PeAfpC) belonging to classes A, B and C, were tested against a representative panel of mycotoxin-producing fungi. They included a total of 38 strains representing 32 different species belonging to the genera Alternaria, Aspergillus, Byssochlamys, Fusarium and Penicillium. PeAfpA exhibited a potent antifungal activity, since the growth of all tested fungi was completely inhibited by concentrations ranging from 0.5 to 16 µg/mL. PdAfpB and PeAfpB, although less effective than PeAfpA, showed significant activity against most of the mycotoxigenic fungi tested. Importantly, PeAfpC previously described as inactive, showed a powerful inhibition against B. spectabilis strains, which are important spoilage and mycotoxin fungi in pasteurized foods. Although less effective than in liquid media, AFPs affected fungal growth on solid media. This study also underlines the potential of these AFPs, in particular PeAfpA, as future antifungal agents for applications in foods, on growing crops or during postharvest storage.


Assuntos
Antifúngicos/farmacologia , Proteínas Fúngicas/farmacologia , Fungos/efeitos dos fármacos , Micotoxinas/metabolismo , Penicillium/metabolismo , Antifúngicos/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fungos/crescimento & desenvolvimento , Fungos/metabolismo , Penicillium/química , Penicillium/genética
17.
Can J Microbiol ; 67(6): 445-450, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33705203

RESUMO

The fungal genus Stemphylium (phylum Ascomycota, teleomorph Pleospora) includes plant pathogenic, endophytic, and saprophytic species with worldwide distributions. Stemphylium spp. produce prodigious numbers of airborne spores, so are a human health concern as allergens. Some species also produce secondary metabolites, such as glucosides, ferric chelates, aromatic polyketides, and others, that function as toxins that damage plants and other fungal species. Some of these compounds also exhibit a low level of mammalian toxicity. The high production of airborne spores by this genus can result in a high incidence of human exposure. Concern about toxin production appears to be the reason that Stemphylium vesicarium, which is a pathogen of several vegetable crops, was classified in Canada as a potential risk of harm to humans for many years. A detailed assessment of the risk of exposure was provided to the relevant regulatory body, the Public Health Agency of Canada, which then determined that Stemphylium spp. in nature or under laboratory conditions posed little to no risk to humans or animals, and the species was re-assigned as a basic (level 1) risk agent.


Assuntos
Ascomicetos/metabolismo , Ascomicetos/patogenicidade , Alérgenos/metabolismo , Alérgenos/toxicidade , Canadá , Humanos , Micotoxinas/metabolismo , Micotoxinas/toxicidade , Doenças das Plantas/microbiologia , Medição de Risco , Metabolismo Secundário , Esporos Fúngicos/metabolismo , Esporos Fúngicos/patogenicidade
18.
Adv Genet ; 107: 193-284, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33641747

RESUMO

Secondary metabolites synthesized by fungi have become a precious source of inspiration for the design of novel drugs. Indeed, fungi are prolific producers of fascinating, diverse, structurally complex, and low-molecular-mass natural products with high therapeutic leads, such as novel antimicrobial compounds, anticancer compounds, immunosuppressive agents, among others. Given that these microorganisms possess the extraordinary capacity to secrete diverse chemical scaffolds, they have been highly exploited by the giant pharma companies to generate small molecules. This has been made possible because the isolation of metabolites from fungal natural sources is feasible and surpasses the organic synthesis of compounds, which otherwise remains a significant bottleneck in the drug discovery process. Here in this comprehensive review, we have discussed recent studies on different fungi (pathogenic, non-pathogenic, commensal, and endophytic/symbiotic) from different habitats (terrestrial and marines), the specialized metabolites they biosynthesize, and the drugs derived from these specialized metabolites. Moreover, we have unveiled the logic behind the biosynthesis of vital chemical scaffolds, such as NRPS, PKS, PKS-NRPS hybrid, RiPPS, terpenoids, indole alkaloids, and their genetic mechanisms. Besides, we have provided a glimpse of the concept behind mycotoxins, virulence factor, and host immune response based on fungal infections.


Assuntos
Produtos Biológicos/química , Produtos Biológicos/farmacologia , Fungos/genética , Fungos/metabolismo , Animais , Evolução Biológica , Produtos Biológicos/metabolismo , Quimioinformática/métodos , Descoberta de Drogas , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/farmacologia , Fungos/patogenicidade , Interações Hospedeiro-Patógeno/imunologia , Humanos , Família Multigênica , Micoses/microbiologia , Micoses/veterinária , Micotoxinas/química , Micotoxinas/metabolismo , Metabolismo Secundário
19.
Org Lett ; 23(7): 2616-2620, 2021 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-33736433

RESUMO

Mycotoxin cyclochlorotine (1) and structurally related astins are cyclic pentapeptides containing unique nonproteinogenic amino acids, such as ß-phenylalanine, l-allo-threonine, and 3,4-dichloroproline. Herein, we report the biosynthetic pathway for 1, which involves intriguing tailoring processes mediated by DUF3328 proteins, including stereo- and regiospecific chlorination and hydroxylation and intramolecular O,N-transacylation. Our findings demonstrate that DUF3328 proteins, which are known to be involved in oxidative cyclization of fungal ribosomal peptides, have much higher functional diversity than previously expected.


Assuntos
Proteínas Fúngicas/genética , Micotoxinas/química , Peptídeos Cíclicos/biossíntese , Fenilalanina/química , Acilação , Aminoácidos/metabolismo , Vias Biossintéticas , Ciclização , Hidroxilação , Estrutura Molecular , Micotoxinas/metabolismo , Oxirredução , Peptídeos Cíclicos/química
20.
Int J Mol Sci ; 22(4)2021 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-33562610

RESUMO

Trichothecenes are the most prevalent mycotoxins contaminating cereal grains. Some of them are also considered as the virulence factors of Fusarium head blight disease. However, the mechanism behind the structure-activity relationship for trichothecenes remains unexplained. Filling this information gap is a crucial step for developing strategies to manage this large family of mycotoxins in food and feed. Here, we perform an in-depth re-examination of the existing structures of Saccharomyces cerevisiae ribosome complexed with three different trichothecenes. Multiple binding interactions between trichothecenes and 25S rRNA, including hydrogen bonds, nonpolar pi stacking interactions and metal ion coordination interactions, are identified as important binding determinants. These interactions are mainly contributed by the key structural elements to the toxicity of trichothecenes, including the oxygen in the 12,13-epoxide ring and a double bond between C9 and C10. In addition, the C3-OH group also participates in binding. The comparison of three trichothecenes binding to the ribosome, along with their binding pocket architecture, suggests that the substitutions at different positions impact trichothecenes binding in two different patterns. Moreover, the binding of trichothecenes induced conformation changes of several nucleotide bases in 25S rRNA. This then provides a structural framework for understanding the structure-activity relationships apparent in trichothecenes. This study will facilitate the development of strategies aimed at detoxifying mycotoxins in food and feed and at improving the resistance of cereal crops to Fusarium fungal diseases.


Assuntos
Micotoxinas/química , Tricotecenos/química , Sítios de Ligação , Grão Comestível/toxicidade , Contaminação de Alimentos , Fusarium/química , Fusarium/patogenicidade , Inativação Metabólica , Modelos Moleculares , Estrutura Molecular , Micotoxinas/metabolismo , Micotoxinas/toxicidade , Conformação de Ácido Nucleico/efeitos dos fármacos , RNA Fúngico/química , RNA Fúngico/efeitos dos fármacos , RNA Ribossômico/química , RNA Ribossômico/efeitos dos fármacos , Ribossomos/efeitos dos fármacos , Ribossomos/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismo , Relação Estrutura-Atividade , Tricotecenos/metabolismo , Tricotecenos/toxicidade
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