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1.
Animals (Basel) ; 14(16)2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39199826

RESUMO

Degnala is one of the primary mycotoxicoses affecting buffaloes, with Fusarium spp. as the main causative agent. This disease is strongly associated with the feeding of rice straw to buffaloes and is considered endemic to regions where rice is cultivated. Cases are concentrated in winter when conditions favor fungal growth in inadequately stored straw. Degnala is characterized by necrosis and gangrene of the extremities, including the tail, lower limbs, ears, tongue, muzzle, and teats. The pelvic limbs are more affected than the thoracic limbs. A tortuous appearance of the tail is very common, and cracks or corneal loss of the hooves may occur, exposing the blades and even the bones. There is no diagnostic method for identifying the disease in animals other than clinical and epidemiological criteria, combined with fungal culture samples. There is no treatment that neutralizes the effects of the toxins; the current treatment is palliative and supportive, consisting of pentasulfate solution, anti-Degnala liquid, 2% nitroglycerin ointment, and broad-spectrum antibiotics for secondary infections. Additionally, the management of drying and proper storage of straw is essential for controlling this disease.

2.
J Fungi (Basel) ; 10(8)2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39194887

RESUMO

Fungi are rich sources of secondary metabolites of agrochemical, pharmaceutical, and food importance, such as mycotoxins, antibiotics, and antitumor agents. Secondary metabolites play vital roles in fungal pathogenesis, growth and development, oxidative status modulation, and adaptation/resistance to various environmental stresses. LaeA contains an S-adenosylmethionine binding site and displays methyltransferase activity. The members of velvet proteins include VeA, VelB, VelC, VelD and VosA for each member with a velvet domain. LaeA and velvet proteins can form multimeric complexes such as VosA-VelB and VelB-VeA-LaeA. They belong to global regulators and are mainly impacted by light. One of their most important functions is to regulate gene expressions that are responsible for secondary metabolite biosynthesis. The aim of this mini-review is to represent the newest cognition of the biosynthetic regulation of mycotoxins and other fungal secondary metabolites by LaeA and velvet proteins. In most cases, LaeA and velvet proteins positively regulate production of fungal secondary metabolites. The regulated fungal species mainly belong to the toxigenic fungi from the genera of Alternaria, Aspergillus, Botrytis, Fusarium, Magnaporthe, Monascus, and Penicillium for the production of mycotoxins. We can control secondary metabolite production to inhibit the production of harmful mycotoxins while promoting the production of useful metabolites by global regulation of LaeA and velvet proteins in fungi. Furthermore, the regulation by LaeA and velvet proteins should be a practical strategy in activating silent biosynthetic gene clusters (BGCs) in fungi to obtain previously undiscovered metabolites.

3.
J Fungi (Basel) ; 10(8)2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39194915

RESUMO

Ochratoxin A (OTA) is a mycotoxin mainly produced by Aspergillus section Circumdati and section Nigri across the coffee chain. OTA is nephrotoxic and is a threat to human health. This review summarizes current knowledge on how to reduce OTA concentration in coffee from farm to cup. After a brief introduction to the OTA occurrence in coffee, current good management practices are introduced. The core of this review focuses on biocontrol and microbial decontamination by lactic acid bacteria, yeasts and fungi, and their associated enzymes currently reported in the literature. Special attention is given to publications closest to in vivo applications of biocontrol agents and microbial OTA adsorption or degradation agents. Finally, this review provides an opinion on which future techniques to promote within the coffee supply chain.

4.
Food Addit Contam Part B Surveill ; 17(3): 261-274, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38982744

RESUMO

Maize grain samples collected from 129 small-scale farmers' stores in southern and southwestern Ethiopia were analysed by LC-MS/MS for a total of 218 mycotoxins and other fungal metabolites of which 15% were regulated mycotoxins. Mycotoxins produced by Penicillium, Aspergillus, and Fusarium accounted for 31%, 17%, and 12% of the metabolites, respectively. Most of the current samples were contaminated by masked and/or emerging mycotoxins with moniliformin being the most prevalent one, contaminating 93% of the samples. Each sample was co-contaminated by 3 to 114 mycotoxins/fungal metabolites. Zearalenone, fumonisin B1, and deoxynivalenol were the dominant mycotoxins, occurring in 78%, 61%, and 55% of the samples with mean concentrations of 243, 429, and 530 µg/kg, respectively. The widespread co-occurrence of several mycotoxins in the samples may pose serious health risks due to synergistic/additional effects.


Assuntos
Contaminação de Alimentos , Fumonisinas , Micotoxinas , Espectrometria de Massas em Tandem , Zea mays , Zea mays/química , Zea mays/microbiologia , Etiópia , Micotoxinas/análise , Contaminação de Alimentos/análise , Fumonisinas/análise , Humanos , Zearalenona/análise , Fusarium/química , Fusarium/metabolismo , Tricotecenos/análise , Penicillium , Aspergillus , Armazenamento de Alimentos , Cromatografia Líquida/métodos , Ciclobutanos
5.
Front Microbiol ; 15: 1394774, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38903800

RESUMO

Sweating is one of the most important processing methods of Chinese medicinal herbs. However, the high temperature and humidity environment required for sweating Chinese medicinal herbs makes it very easy for fungi to breed, especially toxigenic fungi. The mycotoxins produced by these fungi will then contaminate the Chinese medicinal herbs. In this study, we explored the changes in mycobiota, toxigenic fungi, and mycotoxins with and without sweating in Radix Dipsaci (RD), a typical representative of traditional Chinese medicine that requires processing through sweating. We also isolated and identified the toxigenic fungi from RD, whether they were subjected to sweating treatment or not, and examined their toxigenic genes and ability. The results showed that the detection rate of mycotoxins (aflatoxins, ochratoxins, zearalenone, and T-2 toxin) in RD with sweating was 36%, which was 2.25-fold higher than that in RD without sweating. We also detected T-2 toxin in the RD with sweating, whereas it was not found in the RD without sweating. The sweating process altered the fungal composition and increased the abundance of Fusarium and Aspergillus in RD. Aspergillus and Fusarium were the most frequently contaminating fungi in the RD. Morphological and molecular identification confirmed the presence of key toxigenic fungal strains in RD samples, including A. flavus, A. westerdijkiae, F. oxysporum and F. graminearum. These four fungi, respectively, carried AflR, PKS, Tri7, and PKS14, which were key genes for the biosynthesis of aflatoxins, ochratoxins, zearalenone, and T-2 toxin. The toxigenic ability of these four fungal strains was verified in different matrices. We also found that A. flavus, A. westerdijkiae, and F. oxysporum were isolated in RD both with sweating and without sweating, but their isolation frequency was significantly higher in the RD with sweating than in the RD without sweating. F. graminearum was not isolated from RD without sweating, but it was isolated from RD with sweating. These findings suggest that the sweating process promotes the expansion of toxigenic fungi and increases the risk of combined mycotoxin contamination in RD.

6.
Braz J Microbiol ; 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38862737

RESUMO

Fusarium verticillioides causes significant decrease in corn yield and quality, and produces fumonisins, which represent a serious risk to human and animal health. Bacillus species can be an effective and environmentally friendly alternative for F. verticillioides biological control. In this study, some properties of cell-free supernatants (CFSs) of two Bacillus spp. identified as Bacillus subtilis (NT1, NT2) as well as the antifungal effect against F. verticillioides 97L were evaluated. B. subtilis NT1 and NT2 were isolated from commercially available fermented whole soybeans (Natto). Antifungal activity was observed in both CFSs of B. subtilis isolates (50-59 mm) obtained by co-culture suggesting that antifungal compound production depends on interaction between bacteria and fungi. Cell-free supernatants from the two B. subtilis isolates inhibited mycelial growth (77%-94%) and conidial germination (22%-74%) of F. verticillioides 97L. In addition, CFSs caused significant morphological changes such as distorted and collapsed hyphae with wrinkled surfaces and the presence of a large amount of extracellular material compared to the control without CFSs. Both B. subtilis isolates (NT1 and NT2) produced extracellular proteases, biosurfactants and polar low molecular weight compounds that probably act synergistically and may contribute to the antifungal activity. Antifungal compounds showed heat and pH stability and resistance to proteolytic enzymes. Furthermore, antifungal compounds showed high polarity, high affinity to water and a molecular weight less than 10 kDa. These results indicated that the two B. subtilis (NT1 and NT2) have potential as biocontrol agents for F. verticillioides.

7.
Mycotoxin Res ; 40(3): 389-399, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38696043

RESUMO

Fifty-four maize grain samples freshly harvested from subsistence farmers' fields in southwestern Ethiopia were analyzed for multiple mycotoxins using liquid chromatography-tandem mass spectrometric (LC-MS/MS) method following extraction by acetonitrile/water/acetic acid on a rotary shaker. The grain samples were contaminated with a total of 164 metabolites, of which Fusarium and Penicillium metabolites were the most prevalent accounting for 27 and 30%, respectively. All the major mycotoxins and derivatives except one (citrinin) were of Fusarium origin. Zearalenone was the most frequent major mycotoxin occurring in 74% of the samples at concentrations of 0.32-1310 µg/kg. It was followed by nivalenol (63%), zearalenone-sulfate (44%), and fumonisin B1 (41%). Nivalenol, nivalenol glucoside, and fusarenon-X were detected at unusually high levels of 8-1700 µg/kg, 21-184 µg/kg, and 33-149 µg/kg, respectively. Deoxynivalenol and DON-3 glucoside contaminated 32% of the samples, each at levels of 15.9-5140 µg/kg and 10-583 µg/kg, respectively. Moniliformin and W493B occurred in 96 and 22% samples at levels of 3.27-4410 µg/kg and 3-652 µg/kg, respectively. Fumonisins were also detected in the samples at levels of 9-6770 µg/kg (B1), 16-1830 µg/kg (B2), 9.5-808 µg/kg (B3), and 1.3-128 µg/kg (A1). This study confirmed the presence of an array of mycotoxins contaminating maize grains right from the field. The effect of the co-occurring mycotoxins on consumers' health should be investigated along with that of the newly emerging ones. Results of the current study call for application of pre-harvest mycotoxin mitigation strategies to safeguard maize-based food and feed.


Assuntos
Contaminação de Alimentos , Micotoxinas , Espectrometria de Massas em Tandem , Zea mays , Zea mays/microbiologia , Zea mays/química , Micotoxinas/análise , Etiópia , Cromatografia Líquida , Contaminação de Alimentos/análise , Fusarium/metabolismo , Fusarium/isolamento & purificação , Fazendeiros , Grão Comestível/microbiologia , Grão Comestível/química , Penicillium/isolamento & purificação , Penicillium/metabolismo
8.
Braz J Microbiol ; 55(2): 1829-1839, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38722522

RESUMO

This study aimed to evaluate the antifungal effect of SC319 sorghum phenolic extract (SPE) on the Aspergillus, Fusarium, Penicillium, Stenocarpella, Colletotrichum, and Macrophomina genera. SPE was extracted by 20% ethanol and used in four assays: (1) against Fusarium verticillioides in solid (PDA) and liquid (PD) potato dextrose media; (2) Minimum Inhibitory Concentration (MIC) assay with 16 fungi isolates; (3) Conidial Germination Rate (CGR) with 14 fungi isolates and (4) Growth Curve (GC) with 11 fungi isolates. There was no reduction in the mycelial growth (colony diameter and dry weight) and in the number of Fusarium verticillioides spores in assay 1 (PDA and PD). The colony's dry weight was almost six times higher in the presence than in the absence of SPE. All SPE samples presented MIC (assay 1) above the maximum concentration tested (5000 µg.mL-1) for the 16 isolates. Also, there was no inhibitory effect of SPE on conidia germination rate (CGR). Oppositely, in GC assay, the control had a higher CFU count than the samples with SPE in 24 h. This result suggests that SPE can delay the fungal growth in the first hours of incubation, which is an important finding that may help reduce the severity of fungal diseases in plants. However, further studies are needed to confirm these results, including sorghum genotypes with different profiles of phenolic compounds. Although the SC319 SPE was not effective as an antifungal agent, it may have potential as a growth promoter of beneficial fungi in the food and pharmaceutical industries.


Assuntos
Antifúngicos , Fungos , Testes de Sensibilidade Microbiana , Fenóis , Extratos Vegetais , Sorghum , Sorghum/microbiologia , Antifúngicos/farmacologia , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Fungos/efeitos dos fármacos , Fungos/crescimento & desenvolvimento , Esporos Fúngicos/efeitos dos fármacos , Esporos Fúngicos/crescimento & desenvolvimento
9.
Artigo em Inglês | MEDLINE | ID: mdl-38662872

RESUMO

Maize is an important crop for the Republic of Moldova and one of the crops most contaminated with mycotoxins. Maize grain obtained from plants cultivated on Moldavian cornfields in 2021 and 2022 were tested for mycotoxigenic risk using qPCR with primers to several fungal genome sequences engaged in mycotoxin synthesis and ELISA test to screen total aflatoxins, fumonisin B1, zearalenone, deoxynivalenol and T-2 toxin. Except for T-2 toxin, the mycotoxin concentrations were under the limits of detection and did not exceed maximum admissible levels for unprocessed grain. Concentrations of T-2 toxin in grain samples did not correlate significantly with the quantity of toxigenic F. sporotrichioides. All of the analysed grain samples were contaminated with at least one toxigenic fungus, and 20% of the samples were infected with seven different species of toxigenic fungi. Accumulation of fungi in maize kernels was affected significantly by the season, and generally a decrease was observed in fungal frequency and quantity under drought conditions. However, several toxigenic Aspergillus and Fusarium fungi that are able to produce aflatoxins and fumonisins under improper storage conditions were found in the kernels during the whole period of monitoring.


Assuntos
Contaminação de Alimentos , Fungos , Micotoxinas , Zea mays , Zea mays/química , Zea mays/microbiologia , Micotoxinas/análise , Micotoxinas/química , Contaminação de Alimentos/análise , Fungos/isolamento & purificação , Moldávia
10.
Food Res Int ; 184: 114272, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38609249

RESUMO

Sichuan bacon represents the most prevalent dry-cured meat product across Southwest China, but it is vulnerable to fungal spoilage. In the present study, a total of 47 Sichuan bacons were obtained from different regions of the Sichuan Province and analyzed for the presence of ochratoxin A (OTA), yielding a positive rate of 23.4 % (11/47). All the observed OTA concentrations exceeded the maximum admissible dose in meat products (1 µg/kg) established by some EU countries, with the highest OTA concentration being 250.75 µg/kg, which raises a food safety concern and reveals the need for a standardized scientific processing protocol. Then, an OTA-producing fungus named 21G2-1A was isolated from positive samples and found to be Aspergillus westerdijkiae. Further characterization suggested a positive correlation between fungal growth and OTA production. The optimal temperature for the former was 25 °C, while it was 20 °C for the latter. Although the A. westerdijkiae strain 21G2-1A demonstrated greater mycelium growth in the presence of NaCl, OTA production was significantly dismissed when the salinity was greater than 5 %. Four lactic acid bacteria (LAB) were screened out as antagonists against the ochratoxigenic fungus. In vitro evaluation of the antagonists revealed that live cells inhibited fungal growth, and adsorption also contributed to OTA removal at different levels. This study sheds some light on OTA control in Sichuan bacon through a biological approach.


Assuntos
Ocratoxinas , Carne de Porco , Adsorção , Aspergillus
11.
Int J Food Microbiol ; 410: 110442, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-37984213

RESUMO

The raw and processed roots of Polygonum multiflorum Thunb is a popular traditional Chinese medicine. However, Polygoni Multiflori Radix is easily contaminated by toxigenic fungi and mycotoxins during harvesting, processing, and transportation, thereby posing a health risk for consumers. This study aims to investigate the presence of fungi on the surface of raw and processed Polygoni Multiflori Radix collected from four producing areas using high-throughput sequencing. Results showed that the phyla Ascomycota and Basidiomycota, the genera Xeromyces, Cystofilobasidium, Eurotium, and Aspergillus were the dominant fungus, and significant differences are presented in four areas and two processed products. Three potential mycotoxin-producing fungi were detected, namely Trichosporon cutaneum, Aspergillus restrictus, and Fusarium oxysporum. The α-diversity and network complexity showed significant differences in four areas. Chao 1 and Shannon were highest in Yunnan (YN), then incrementally decreased from SC (Sichuan) to AH (Anhui) and GD (Guangdong) areas. Meanwhile, α-diversity was also strongly influenced by processing. Chao 1 and Shannon indices were higher in the raw group, however, the network complexity and connectivity were higher in the processed group. In conclusion, the assembly and network of the surface microbiome on Polygoni Multiflori Radix were influenced by sampling location and processing. This work provides details on the surface microbiome of Polygoni Multiflori Radix samples, which could ensure the drug and consumers' safety.


Assuntos
Medicamentos de Ervas Chinesas , Micotoxinas , Polygonum , China , Medicina Tradicional Chinesa , Raízes de Plantas
12.
J Appl Microbiol ; 134(12)2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38049375

RESUMO

AIMS: The antifungal effect of the yeast species Kluyveromyces marxianus, Meyerozyma caribbica, and Wickerhamomyces anomalus was evaluated against two Fusarium graminearum strains (FRS 26 and FSP 27) in vitro and on corn seeds. METHODS AND RESULTS: The antifungal effect of the yeasts against F. graminearum was evaluated using scanning electron microscopy and extracellular chitinase and glucanase production to further elucidate the biocontrol mode of action. In addition, the germination percentage and vigor test were investigated after applying yeast on corn seeds. All the yeast strains inhibited fungal growth in vitro (57.4%-100.0%) and on corn seeds (18.9%-87.2%). In co-culture with antagonistic yeasts, F. graminearum showed collapsed hyphae and turgidity loss, which could be related to the ability of yeasts to produce chitinases and glucanases. The three yeasts did not affect the seed corn germination, and W. anomalus and M. caribbica increased corn seed growth parameters (germination percentage, shoot and root length, and shoot dry weight). CONCLUSION: Meyerozyma caribbica and W. anomalus showed satisfactory F. graminearum growth inhibition rates and did not affect seed growth parameters. Further studies are required to evaluate the application of these yeasts to the crop in the field.


Assuntos
Antifúngicos , Fusarium , Antifúngicos/farmacologia , Zea mays , Leveduras , Doenças das Plantas/prevenção & controle , Doenças das Plantas/microbiologia
13.
Food Res Int ; 173(Pt 2): 113388, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37803726

RESUMO

Aspergillus ochraceus is an ochratoxin-producing fungus which contaminates coffee. In this study the antifungal effect of the yeast Hanseniaspora opuntiae on three Aspergillus ochraceus strains (IOC 4417, IOC 4462, Ao 14) was evaluated in vitro and on coffee fruits. H. opuntiae (106 and 107 cells mL-1) reduced in vitro fungal growth from 82% to 87%, when co-cultivated with A. ochraceus. The yeast cell free supernatant (CFS) inhibited conidial germination from 76.5% to 92.5%, and hyphal growth from 54% to 78%. The yeast (107 and 109 cells mL-1) applied on coffee fruits delayed fruit decay by A. ochraceus (IOC 4417 and Ao 14) until the 9th day, and was significantly different (p < 0.05) from the controls. Furthermore, the ultrastructure of the yeast-fungus interaction on the coffee fruit surface showed yeast attachment to A. ochraceus hyphae, and morphological alterations in fungal structures, with hyphal abnormalities, such as tortuous hyphae with irregular, non-uniform surface compared to the control without yeast. H. opuntiae showed efficacy as biocontrol agent and, to the best of our knowledge, this is the first study on the antifungal activity of H. opuntiae against A. ochraceus on coffee fruits Nevertheless, application of H. opuntiae to the crop in the field requires further studies.


Assuntos
Aspergillus ochraceus , Café , Café/metabolismo , Frutas/microbiologia , Antifúngicos/farmacologia
14.
Foods ; 12(19)2023 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-37835201

RESUMO

The milk's natural flora, or the starter, can preserve cheesemaking and allow for microbial competition. This investigation aimed to improve cheese safety and assess its characteristics using probiotic cell pellets (LCP) or cell-free extracts (CFS). Cheese samples were collected from different areas to investigate the current contamination situation. Six CFSs of probiotics were assessed as antifungal against toxigenic fungi using liquid and solid media and their aflatoxin reduction impact. The most effective CFS was chosen for cheese coating in nanoemulsion. Coated cheese with CFS, LCP, and LCP-CFS was assessed against control for changes in chemical composition, ripening indications, rheological properties, and microbiology. Results showed significant contamination levels in the collected samples, and toxic fungi were present. Lactobacillus rhamnosus CFS has aflatoxins reducibility in liquid media. During cheese ripening, uncoated cheese showed higher fat, protein, salt content, soluble nitrogen, total volatile fatty acids, tyrosine, and tryptophan contents than coated samples, except for LCP-coating treatment. Cheese rheology indicated that coating treatments had the lowest hardness, cohesiveness, gumminess, chewiness, and springiness compared to uncoated cheese. Uncoated cheese had the highest yeast and mold counts compared to the treated ones. The LCP-CFS-coated cheese showed no Aspergillus cells for up to 40 days. Uncoated Ras cheese recorded slightly lower flavor, body, texture, and appearance scores than coated cheeses. In conclusion, coating cheese with L. rhamnosus nanoemulsion has antifungal and antiaflatoxigenic properties, even for LCP, CFS, and CFS-LCP, which could extend cheese shelf life.

15.
Food Res Int ; 172: 112774, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37689839

RESUMO

Levels of aflatoxin B1 (AFB1) were measured during the production of wheat craft beer made with wheat malt contaminated with AFB1 (1.23 µg/kg). A wheat craft beer made with non-contaminated wheat malt was produced for comparison purposes. AFB1 was measured after mashing (malt after the mashing process), and in spent grain (spent grains are filtered to collect the wort - remaining sugar-rich liquid), sweet wort, green beer, spent yeast, and in beer. Physicochemical parameters (pH, titratable acidity, color parameters, total soluble solids), sugars, organic acids, alcohols, and phenolics were evaluated after mashing, and in sweet wort, green beer, and beer samples. Density and yeast counts were determined over 120 h of sweet wort fermentation every 24 h. The AFB1 levels in the final beer were 0.22 µg/L, while the spent grains and spent yeasts contained 0.71 ± 0.17 and 0.11 ± 0.03 µg/kg of AFB1, respectively. AFB1 contamination did not influence the final product's physicochemical parameters, density during fermentation, fructose, or glycerol content. Higher yeast counts were observed during the first 48 h of non-contaminated wheat craft beer fermentation, with higher ethanol, citric acid, and propionic acid contents and lower glucose, malic acid, and lactic acid contents compared with beer contaminated with AFB1. Non-contaminated wheat craft beer also had higher concentrations of gallic acid, chlorogenic acid, catechin, procyanidin A2, and procyanidin B1. AFB1 contamination of wheat malt may not affect basic quality parameters in wheat craft beer but can influence the final product's organic acid and phenolic contents. Our findings show that if wheat craft beer is made with contaminated malt, AFB1 can remain in the final product and may pose a risk to consumers.


Assuntos
Triticum , Fermento Seco , Saccharomyces cerevisiae , Cerveja , Fermentação
16.
Artigo em Inglês | MEDLINE | ID: mdl-37640447

RESUMO

Members within the Fusarium sambucinum species complex (FSAMSC) are able to produce mycotoxins, such as deoxynivalenol (DON), nivalenol (NIV), zearalenone (ZEN) and enniatins (ENNs) in food products. Consequently, alternative methods for assessing the levels of these mycotoxins are relevant for quick decision-making. In this context, qPCR based on key mycotoxin biosynthetic genes could aid in determining the toxigenic fungal biomass, and could therefore infer mycotoxin content. The aim of this study was to verify the use of qPCR as a technique for estimating DON, NIV, ENNs and ZEN, as well as Fusarium graminearum sensu lato (s.l.) and F. poae in barley grains. For this purpose, 53 barley samples were selected for mycobiota, mycotoxin and qPCR analyses. ENNs were the most frequent mycotoxins, followed by DON, ZEN and NIV. 83% of the samples were contaminated by F. graminearum s.l. and 51% by F. poae. Pearson correlation analysis showed significant correlations for TRI12/15-ADON with DON, ESYN1 with ENNs, TRI12/15-ADON and ZEB1 with F. graminearum s.l., as well as ESYN1 and TRI12/NIV with F. poae. Based on the results, qPCR could be useful for the assessment of Fusarium presence, and therefore, provide an estimation of its mycotoxins' levels from the same sample.


Assuntos
Fusarium , Hordeum , Micotoxinas , Zearalenona , Micotoxinas/análise , Fusarium/genética , Zearalenona/análise , Reação em Cadeia da Polimerase/métodos , Grão Comestível/química
17.
Toxins (Basel) ; 15(1)2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-36668865

RESUMO

Pathogenic fungi in the genera Alternaria, Aspergillus, Botrytis, Fusarium, Geotrichum, Gloeosporium, Monilinia, Mucor, Penicillium, and Rhizopus are the most common cause of pre- and postharvest diseases of fruit, vegetable, root and grain commodities. Some species are also able to produce mycotoxins, secondary metabolites having toxic effects on human and non-human animals upon ingestion of contaminated food and feed. Synthetic fungicides still represent the most common tool to control these pathogens. However, long-term application of fungicides has led to unacceptable pollution and may favour the selection of fungicide-resistant mutants. Microbial biocontrol agents may reduce the incidence of toxigenic fungi through a wide array of mechanisms, including competition for the ecological niche, antibiosis, mycoparasitism, and the induction of resistance in the host plant tissues. In recent years, the emission of volatile organic compounds (VOCs) has been proposed as a key mechanism of biocontrol. Their bioactivity and the absence of residues make the use of microbial VOCs a sustainable and effective alternative to synthetic fungicides in the management of postharvest pathogens, particularly in airtight environments. In this review, we will focus on the possibility of applying yeast VOCs in the biocontrol of mycotoxigenic fungi affecting stored food and feed.


Assuntos
Armas de Fogo , Fungicidas Industriais , Micotoxinas , Perfumes , Compostos Orgânicos Voláteis , Animais , Micotoxinas/metabolismo , Saccharomyces cerevisiae/metabolismo , Compostos Orgânicos Voláteis/farmacologia , Compostos Orgânicos Voláteis/metabolismo , Fungicidas Industriais/farmacologia , Fungos/metabolismo , Alternaria/metabolismo
18.
Heliyon ; 9(1): e12835, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36647362

RESUMO

Ochratoxin A (OTA) is a toxic fungal metabolite produced by some Aspergillus and Penicillium species. This work was designed to explore the presence of OTA and ochratoxigenic fungi in feed grains marketed in Qatar and their biological control by a bacterium (Burkholderia cepacia). Significantly higher levels of OTA were detected in mixed grains samples (144.59 ± 6.63 µg/kg), compared to the maize (25.27 ± 1.89 µg/kg) and wheat (3.37 ± 0.11 µg/kg). OTA-producing fungi (A. niger, A. ochraceus, A. westerdijkiae, A. carbonarius and P. verrucosum) were identified on the basis of their morphological features as well as through polymerase chain reaction (PCR). Putative ochratoxigenic polyketide genes in these isolates were evidenced by using primers AoOTA-L/AoOTA-R (in A. ochraceus and A. westerdijkiae), AoPks1/AoPks2 (in A. niger and A. ochraceus) and PenPks1/Penpks2 (in P. verrucosum). On synthetic media, A. westerdijkiae showed the highest OTA synthesis (5913 ± 576 µg/kg) than the closely related A. ochraceus (3520 ± 303 µg/kg), A. carbonarius (3064 ± 289 µg/kg) and P. verrucosum (3030 ± 710 µg/kg). Burkholderia cepacia cells and culture extract showed promising biological control potentials against OTA producing fungi. On the basis of these findings, it can be concluded that animal feed samples are generally contaminated with OTA-producing fungi as well as OTA, and Burkholderia cepacia CS5 exhibits promising antifungal activities.

19.
Food Chem ; 402: 134159, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36137380

RESUMO

Few reports are on the application of cold plasma (CP) for mold and mycotoxin control in grain. The aim of this study was to evaluate the viability of CP for mycotoxin and mold control in rice grain. Rice grains artificially contaminated with molds or mycotoxins were subjected to CP treatment. The microbial activities of Aspergillus niger, Rhizopus oryzae, Penicillium verrucosum and Fusarium graminearum were significantly inhibited by CP treatment. The maximal reduction of DON and OTA were 61.25 % and 55.64 %, respectively. The electrical conductivity and malondialdehyde content in rice grain increased at most by 30.14 % and 103.27 %, respectively. The seed germination reduced significantly when treatment time reached 8 min. The major nutrients of rice grain were not affected except for prolamine, which was generally consistent with the results of electron microscopy and Fourier-transform infrared analysis. Cold plasma is a promising method for mold and mycotoxin control in rice grain.


Assuntos
Fusarium , Micotoxinas , Oryza , Gases em Plasma , Micotoxinas/análise , Descontaminação , Grão Comestível/química , Fungos , Malondialdeído , Fenilpropanolamina , Contaminação de Alimentos/análise
20.
Foods ; 12(23)2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-38231837

RESUMO

Cereal grains serve as the cornerstone of global nutrition, providing a significant portion of humanity's caloric requirements. However, the presence of fungal genera, such Fusarium, Penicillium, Aspergillus, and Alternaria, known for their mycotoxin-producing abilities, presents a significant threat to human health due to the adverse effects of these toxins. The primary objective of this study was to identify the predominant fungal contaminants in cereal grains utilized in breadmaking, as well as in flour and bread. Moreover, a systematic review, including meta-analysis, was conducted on the occurrence and levels of mycotoxins in wheat flour from the years 2013 to 2023. The genera most frequently reported were Fusarium, followed by Penicillium, Aspergillus, and Alternaria. Among the published reports, the majority focused on the analysis of Deoxynivalenol (DON), which garnered twice as many reports compared to those focusing on Aflatoxins, Zearalenone, and Ochratoxin A. The concentration of these toxins, in most cases determined by HPLC-MS/MS or HPLC coupled with a fluorescence detector (FLD), was occasionally observed to exceed the maximum limits established by national and/or international authorities. The prevalence of mycotoxins in flour samples from the European Union (EU) and China, as well as in foods intended for infants, exhibited a significant reduction compared to other commercial flours assessed by a meta-analysis investigation.

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