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1.
Food Chem ; 322: 126757, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32283378

RESUMO

In the present work, for the first time, the filamentous fungus Fusarium sp. was utilized for devising a novel method for pre-concentration and determination of trace amounts of Pb(II), Cu(II), Cd(II), and Zn(II) ions, using a mini-column packed with Fusarium-coated multi-walled carbon nanotubes and inductively coupled plasma-optical emission spectrometry. Optimal analytical conditions including pH, ionic strength, elution solution, sample and eluent flow rates, and sample volume were determined. The detection limits were 0.39, 0.060, 0.021, and 0.025 ng mL-1 for Pb(II), Cu(II), Cd(II), and Zn(II) cations, respectively. This new method demonstrated a high performance for the analytes, and their adsorption was not affected by the different co-existing ions. The present procedure was validated by the analysis of standard reference materials, since the obtained data were in close agreement with reference values. Finally, this new procedure was successfully applied to analysis of heavy metal cations in natural food and water samples.


Assuntos
Fusarium/química , Metais Pesados/análise , Nanotubos de Carbono/química , Extração em Fase Sólida , Espectrofotometria/métodos , Adsorção , Cátions/química , Células Imobilizadas/química , Cobre/análise , Água Doce/análise , Concentração de Íons de Hidrogênio , Chumbo/análise , Chumbo/isolamento & purificação , Limite de Detecção , Metais Pesados/isolamento & purificação , Metais Pesados/normas , Concentração Osmolar , Padrões de Referência , Espectrofotometria/normas
2.
Toxicol Lett ; 326: 52-60, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32119988

RESUMO

Zearalenone, produced by various Fusarium species, is a non-steroidal estrogenic mycotoxin that contaminates cereals, resulting in adverse effects on human health. We investigated the effects of zearalenone and its metabolite alpha zearalenol on epigenetic modifications and its relationship with metabolic pathways in human hepatocellular carcinoma cells following 24 h of exposure. Zearalenone and alpha zearalenol at the concentrations of 1, 10 and 50 µM significantly increased global levels of DNA methylation and global histone modifications (H3K27me3, H3K9me3, H3K9ac). Expression levels of the chromatin modifying enzymes EHMT2, ESCO1, HAT1, KAT2B, PRMT6 and SETD8 were upregulated by 50 µM of zearalenone exposure using PCR arrays, consistent with the results of global histone modifications. Zearalenone and alpha zearalenol also changed expression levels of the AhR, LXRα, PPARα, PPARÉ£, L-fabp, LDLR, Glut2, Akt1 and HK2 genes, which are related to nuclear receptors and metabolic pathways. PPARÉ£, a key regulator of lipid metabolism, was selected from among these genes for further analysis. The PPARÉ£ promoter reduced methylation significantly following zearalenone exposure. Taken together, the epigenetic mechanisms of DNA methylation and histone modifications may be key mechanisms in zearalenone toxicity. Furthermore, effects of zearalenone in metabolic pathways could be mediated by epigenetic modifications.


Assuntos
Epigênese Genética/efeitos dos fármacos , Fusarium/química , Expressão Gênica/efeitos dos fármacos , Células Hep G2/efeitos dos fármacos , Micotoxinas/toxicidade , Zearalenona/toxicidade , Zeranol/análogos & derivados , Metilação de DNA/efeitos dos fármacos , Células Hep G2/metabolismo , Humanos , Zeranol/metabolismo , Zeranol/toxicidade
3.
PLoS Pathog ; 16(3): e1008323, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32163521

RESUMO

Fusarium is a genus of filamentous fungi that includes species that cause devastating diseases in major staple crops, such as wheat, maize, rice, and barley, resulting in severe yield losses and mycotoxin contamination of infected grains. Phenamacril is a novel fungicide that is considered environmentally benign due to its exceptional specificity; it inhibits the ATPase activity of the sole class I myosin of only a subset of Fusarium species including the major plant pathogens F. graminearum, F. asiaticum and F. fujikuroi. To understand the underlying mechanisms of inhibition, species specificity, and resistance mutations, we have determined the crystal structure of phenamacril-bound F. graminearum myosin I. Phenamacril binds in the actin-binding cleft in a new allosteric pocket that contains the central residue of the regulatory Switch 2 loop and that is collapsed in the structure of a myosin with closed actin-binding cleft, suggesting that pocket occupancy blocks cleft closure. We have further identified a single, transferable phenamacril-binding residue found exclusively in phenamacril-sensitive myosins to confer phenamacril selectivity.


Assuntos
Cianoacrilatos/química , Proteínas Fúngicas/química , Fungicidas Industriais/química , Fusarium/enzimologia , Miosina Tipo I/química , Cianoacrilatos/farmacologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fungicidas Industriais/farmacologia , Fusarium/química , Fusarium/efeitos dos fármacos , Fusarium/genética , Miosina Tipo I/genética , Miosina Tipo I/metabolismo , Doenças das Plantas/microbiologia , Triticum/microbiologia , Zea mays/microbiologia
4.
Nat Prod Res ; 34(3): 335-340, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30602315

RESUMO

Two new α-pyrones, fupyrones A and B (1 and 2) and a biosynthetically related known α-pyrone, 4-methyl-5,6-dihydro-2H-pyran-2-one (3), were isolated from an endophytic fungus, Fusarium sp. F20, harbored in the stems of the Chinese medicinal plant Mahonia fortunei. Their structures were determined on the basis of spectroscopic data including MS and NMR. The antibacterial efficacies of compounds 1-3 were evaluated against four selected Gram-positive and Gram-negative bacteria, and their quorum sensing inhibitory activity was also investigated against the test organism, Chromobacterium violaceum.


Assuntos
Antibacterianos/isolamento & purificação , Fusarium/química , Pironas/isolamento & purificação , Antibacterianos/química , Antibacterianos/farmacologia , Endófitos/química , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Estrutura Molecular , Plantas Medicinais/microbiologia , Pironas/química , Percepção de Quorum/efeitos dos fármacos
5.
Chemosphere ; 240: 124876, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31542577

RESUMO

4-t-octylphenol (4-t-OP), a well-known endocrine disrupting compound, is frequently found in various environmental compartments at levels that may cause adverse effects to the ecosystem and public health. To date, most of the studies that investigate microbial transformations of 4-t-OP have focused on the process mediated by bacteria, ligninolytic fungi, or microbial consortia. There is no report on the complete degradation mechanism of 4-t-OP by non-ligninolytic fungi. In this study, we conducted laboratory experiments to explore and characterize the non-ligninolytic fungal strain Fusarium falciforme RRK20 to degrade 4-t-OP. Using the response surface methodology, the initial biomass concentration and temperature were the factors identified to be more influential on the efficiency of the biodegradation process as compared with pH. Under the optimized conditions (i.e., 28 °C, pH 6.5 with an initial inoculum density of 0.6 g L-1), 25 mg L-1 4-t-OP served as sole carbon source was completely depleted within a 14-d incubation; addition of low dosage of glucose was shown to significantly accelerate 4-t-OP degradation. The yeast estrogenic screening assay further confirmed the loss of estrogenic activity during the biodegradation process, though a longer incubation period was required for complete removal of estrogenicity. Metabolites identified by LC-MS/MS revealed that strain RRK20 might degrade 4-t-OP as sole energy source via alkyl chain oxidation and aromatic ring hydroxylation pathways. Together, these results not only suggest the potential use of non-ligninolytic fungi like strain RRK20 in remediation of 4-t-OP contaminated environments but may also improve our understanding of the environmental fate of 4-t-OP.


Assuntos
Biodegradação Ambiental , Fusarium/química , Fenóis/química , Fungos/metabolismo
6.
Sensors (Basel) ; 20(1)2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31861503

RESUMO

Fusarium head blight in winter wheat ears produces the highly toxic mycotoxin deoxynivalenol (DON), which is a serious problem affecting human and animal health. Disease identification directly on ears is important for selective harvesting. This study aimed to investigate the spectroscopic identification of Fusarium head blight by applying continuous wavelet analysis (CWA) to the reflectance spectra (350 to 2500 nm) of wheat ears. First, continuous wavelet transform was used on each of the reflectance spectra and a wavelet power scalogram as a function of wavelength location and the scale of decomposition was generated. The coefficient of determination R2 between wavelet powers and the disease infestation ratio were calculated by using linear regression. The intersections of the top 5% regions ranking in descending order based on the R2 values and the statistically significant (p-value of t-test < 0.001) wavelet regions were retained as the sensitive wavelet feature regions. The wavelet powers with the highest R2 values of each sensitive region were retained as the initial wavelet features. A threshold was set for selecting the optimal wavelet features based on the coefficient of correlation R obtained via the correlation analysis among the initial wavelet features. The results identified six wavelet features which include (471 nm, scale 4), (696 nm, scale 1), (841 nm, scale 4), (963 nm, scale 3), (1069 nm, scale 3), and (2272 nm, scale 4). A model for identifying Fusarium head blight based on the six wavelet features was then established using Fisher linear discriminant analysis. The model performed well, providing an overall accuracy of 88.7% and a kappa coefficient of 0.775, suggesting that the spectral features obtained using CWA can potentially reflect the infestation of Fusarium head blight in winter wheat ears.


Assuntos
Fusarium/química , Doenças das Plantas/microbiologia , Triticum/microbiologia , Análise de Ondaletas , Análise Discriminante , Fusarium/isolamento & purificação , Espectrofotometria , Triticum/química
7.
J Agric Food Chem ; 67(43): 11994-12001, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31618578

RESUMO

Bioactivity-guided isolation of the endophytic fungus Fusarium sambucinum TE-6L residing in Nicotiana tabacum L. led to the discovery of two new angularly prenylated indole alkaloids (PIAs) with pyrano[2,3-g]indole moieties, amoenamide C (1) and sclerotiamide B (2), and four known biosynthetic congeners (3-6). Their structures were determined by comprehensive spectroscopic techniques, electronic circular dichroism (ECD), and X-ray diffraction. Compound 1 containing the bicyclo[2.2.2]diazaoctane core and indoxyl unit is rarely reported. All the compounds were evaluated for their antimicrobial and insecticidal activities. Notably, compounds 1-3 showed potent inhibitory effects against three human- and one plant-pathogenic bacterium, and seven plant-pathogenic fungi. Compounds 2-4 also exhibited remarkable larvicidal activity against first instar larvae of the cotton bollworm Helicoverpa armigera with mortality rates of 70.2%, 83.2%, and 70.5%, respectively. Further toxicity tests on zebrafish embryos were performed to evaluate the potential toxicity of PIAs. Of significance was that compound 3 in particular exhibited the highest activities but the lowest effects on the hatching of embryos among all the compounds. This study provides a basis for understanding developmental toxicity of PIAs exposure to zebrafish embryos, and also indicates the potential environmental risks of other natural compounds exposure in the aquatic ecosystem.


Assuntos
Anti-Infecciosos/química , Endófitos/química , Fusarium/química , Alcaloides Indólicos/química , Inseticidas/química , Animais , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Endófitos/isolamento & purificação , Fungos/efeitos dos fármacos , Fusarium/isolamento & purificação , Alcaloides Indólicos/metabolismo , Alcaloides Indólicos/farmacologia , Inseticidas/metabolismo , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Mariposas/efeitos dos fármacos , Tabaco/microbiologia , Peixe-Zebra/embriologia
8.
Molecules ; 24(19)2019 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-31561557

RESUMO

Chemical analyses of Fusarium avenaceum grown on banana medium resulted in eight novel spiroleptosphols, T1, T2 and U-Z (1-8). The structures were elucidated by a combination of high-resolution mass spectrometric data and 1- and 2-D NMR experiments. The relative stereochemistry was assigned by 1H coupling and NOESY/ROESY experiments. Absolute stereochemistry established for 7 by vibrational circular dichroism was found analogous to that of the putative polyketide spiroleptosphol from Leptosphaeria doliolum.


Assuntos
Fusarium/química , Compostos de Espiro/química , Fenômenos Químicos , Cromatografia Líquida de Alta Pressão , Fusarium/metabolismo , Espectroscopia de Ressonância Magnética , Redes e Vias Metabólicas , Estrutura Molecular , Compostos de Espiro/metabolismo
9.
Fungal Biol ; 123(8): 618-624, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31345416

RESUMO

This study examined the effect of climate change (CC) abiotic factors of temperature (20, 25, 30 °C), water activity (aw; 0.995, 0.98) and CO2 exposure (400, 1000 ppm) may have on (a) growth, (b) gene expression of biosynthetic toxin genes (Tri5, Tri6, Tri16), and (c) T-2/HT-2 toxins and associated metabolites by Fusarium langsethiae on oat-based media and in stored oats. Lag phases and growth were optimum at 25 °C with freely available water. This was significantly reduced at 30 °C, at 0.98 aw and 1000 ppm CO2 exposure. In oat-based media and stored oats, Tri5 gene expression was reduced in all conditions except 30 °C, 0.98 aw, elevated CO2 where there was a significant (5.3-fold) increase. The Tri6 and Tri16 genes were upregulated, especially in elevated CO2 conditions. Toxin production was higher at 25 °C than 30 °C. In stored oats, at 0.98 aw, elevated CO2 led to a significant increase (73-fold) increase in T2/HT-2 toxin, especially at 30 °C. Nine T-2 and HT-2 related metabolites were detected, including a new dehydro T-2 toxin (which correlated with T-2 production) and the conjugate, HT-2 toxin, glucuronide. This shows that CC factors may have a significant impact on growth and mycotoxin production by F. langsethiae.


Assuntos
Avena/química , Avena/microbiologia , Proteínas Fúngicas/genética , Fusarium/crescimento & desenvolvimento , Fusarium/genética , Micotoxinas/análise , Mudança Climática , Contaminação de Alimentos/análise , Armazenamento de Alimentos , Proteínas Fúngicas/metabolismo , Fusarium/química , Fusarium/metabolismo , Micotoxinas/metabolismo , Sementes/química , Sementes/microbiologia , Toxina T-2/análogos & derivados , Toxina T-2/análise , Toxina T-2/biossíntese , Toxina T-2/metabolismo
10.
Lipids ; 54(9): 543-556, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31353474

RESUMO

Fusarium oxysporum f. sp. tulipae (FOT) secretes (+)-7-iso-jasmonoyl-(S)-isoleucine ((+)-JA-Ile) to the growth medium together with about 10 times less 9,10-dihydro-(+)-7-iso-JA-Ile. Plants and fungi form (+)-JA-Ile from 18:3n-3 via 12-oxophytodienoic acid (12-OPDA), which is formed sequentially by 13S-lipoxygenase, allene oxide synthase (AOS), and allene oxide cyclase (AOC). Plant AOC does not accept linoleic acid (18:2n-6)-derived allene oxides and dihydrojasmonates are not commonly found in plants. This raises the question whether 18:2n-6 serves as the precursor of 9,10-dihydro-JA-Ile in Fusarium, or whether the latter arises by a putative reductase activity operating on the n-3 double bond of (+)-JA-Ile or one of its precursors. Incubation of pentadeuterated (d5 ) 18:3n-3 with mycelia led to the formation of d5 -(+)-JA-Ile whereas d5 -9,10-dihydro-JA-Ile was not detectable. In contrast, d5 -9,10-dihydro-(+)-JA-Ile was produced following incubation of [17,17,18,18,18-2 H5 ]linoleic acid (d5 -18:2n-6). Furthermore, 9(S),13(S)-12-oxophytoenoic acid, the 15,16-dihydro analog of 12-OPDA, was formed upon incubation of unlabeled or d5 -18:2n-6. Appearance of the α-ketol, 12-oxo-13-hydroxy-9-octadecenoic acid following incubation of unlabeled or [13 C18 ]-labeled 13(S)-hydroperoxy-9(Z),11(E)-octadecadienoic acid confirmed the involvement of AOS and the biosynthesis of the allene oxide 12,13(S)-epoxy-9,11-octadecadienoic acid. The lack of conversion of this allene oxide by AOC in higher plants necessitates the conclusion that the fungal AOC is distinct from the corresponding plant enzyme.


Assuntos
Ciclopentanos/metabolismo , Fusarium/química , Oxirredutases Intramoleculares/metabolismo , Ácido Linoleico/metabolismo , Oxilipinas/metabolismo , Ciclopentanos/química , Fusarium/metabolismo , Ácido Linoleico/química , Conformação Molecular , Oxilipinas/química
11.
Int J Biol Macromol ; 137: 568-575, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31279885

RESUMO

Two polysaccharides, DGS1 and DGS2, were obtained by solid-state fermentation (SSF) of Fusarium solani DO7, an endophytic fungus isolated from the orchid Dendrobium officinale. Structural characterizations revealed that DGS1 consisted of arabinose, glucose, mannose and galactose with a molar ratio of 2.9:13.4:3.0:1, respectively, and contained (1 → 5)-Araf, (1 → 4)-Glcp, (1 → 6)-Glcp, (1 → 3)-Manp, (1 → 2,6)-Manp and (1 → 6)-Galp glycosidic linkages, while DGS2 was composed of arabinose, glucose, mannose and galactose in a molar ratio of 3.5:8.1:2.1:1, respectively, and contained (1 → 5)-Araf, (1 → 4)-Glcp, (1 → 6)-Glcp, (1 → 3)-Manp and (1 → 6)-Galp glycosidic linkages. Neither polysaccharide was toxic to human embryonic kidney cells or mouse RAW 264.7 macrophage cells. An immunomodulatory activity assay indicated that both polysaccharides could significantly enhance the levels of TNF-α, IL-6 and NO by activating TNF-α, IL-6 and iNOs gene expression, respectively, especially DGS2. Interestingly, DGS2 also possessed relatively high antioxidant activity. These results illustrate that, due to its cost-effectiveness and environmentally friendly features, SSF has significant potential as a commercially competitive source of natural products, including fungal polysaccharides, with immunomodulatory activity.


Assuntos
Fermentação , Polissacarídeos Fúngicos/química , Polissacarídeos Fúngicos/farmacologia , Fusarium/química , Fusarium/metabolismo , Fatores Imunológicos/química , Fatores Imunológicos/farmacologia , Animais , Antioxidantes/química , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Polissacarídeos Fúngicos/biossíntese , Glicosilação , Células HEK293 , Humanos , Fatores Imunológicos/biossíntese , Metilação , Camundongos , Peso Molecular , Monossacarídeos/análise , Fagocitose/efeitos dos fármacos , Células RAW 264.7
12.
J Agric Food Chem ; 67(30): 8411-8418, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31246458

RESUMO

Economic loss of postharvest wheat under poor storage conditions due to fungal spoilage and mycotoxin contamination is severe. In order to study the influencing factors of the aggravation of mildew in natural wheat during storage, we assessed changes in Fusarium mycotoxins by high performance liquid chromatography, changes in fungal communities by high-throughput sequencing, and changes in biochemical components in wheat stored under artificial simulation conditions. Deoxynivalenol was the dominant Fusarium mycotoxin, reaching 1103 µg/kg at 25 °C with 75% relative humidity after 30 weeks. Under these conditions, Fusarium dominated the fungal communities, and Fusarium graminearum was significantly negatively correlated with glutenin (p < 0.05). Low storage temperatures and low humidity result in lower levels of Fusarium mycotoxins. Different fungi tended to consume different wheat components, and the interaction between environmental and biological factors eventually leads to the deterioration of wheat quality. These findings might provide valuable information for control strategies of mildew occurrence during grain storage.


Assuntos
Fungos/isolamento & purificação , Micobioma , Micotoxinas/química , Triticum/microbiologia , Cromatografia Líquida de Alta Pressão , Contaminação de Alimentos/análise , Armazenamento de Alimentos , Fungos/classificação , Fungos/genética , Fusarium/química , Fusarium/classificação , Fusarium/isolamento & purificação , Fusarium/metabolismo , Umidade , Micotoxinas/metabolismo , Sementes/química , Sementes/microbiologia , Tricotecenos/análise , Tricotecenos/metabolismo , Triticum/química
13.
Pharm Biol ; 57(1): 310-317, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31161849

RESUMO

Context: Nigerian soil fungi population is unexplored. It is hypothesized that they harbour new bioactive chemicals. This hypothesis is based on the large percentage of currently approved medicines that originated from soil-inhabiting micro-organisms Objectives: To investigate the antimicrobial and anti-inflammatory properties of Fusarium solani ethyl acetate (EtOAc) extract selected based on its broad spectrum of antimicrobial potential in an overlay experiment with seven other soil fungi strains. Materials and methods: Fungus number 6 (F6), identified by molecular characterization as Fusarium solani (Mart.) Sacc (Nectriaceae) was selected for studies from eight purified soil fungi due to its superior broad-spectrum antibiotics producing potential following agar overlay experiment. F6 was fermented for 21 d and the minimum inhibitory concentration (MIC) of its EtOAc fermentation extract (dose range: 12.5-100 µg/mL) was determined using agar dilution method for Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Salmonella typhi and anti-inflammatory properties determined using rat-paw (250-500 mg/kg) and xylene induced oedema (250-500 µg/kg) (in Swiss albino rats and mice) models, respectively. The ability of the extract to inhibit cyclooxygenase (COX) enzyme was also determined in vitro using Cayman test kit-760111. Result: The MIC of the EtOAc extract was <12.5 µg/mL for S. aureus, P. aeruginosa and Escherichia coli. It inhibited xylene induced oedema by 65% compared with 61% observed for diclofenac and was significantly (p < 0.05) better than diclofenac in rat-paw-oedema model within the first phase of inflammation. The extract inhibited COX-1 peroxidase-mediated activities with an IC50 below 5 µg/mL. Conclusions: The extract exhibited strong antibacterial and anti-inflammatory properties, warranting further investigations into therapeutic potential of this fungus. This study design can be adapted in soil fungi metabolomic investigations. We report for the first time the potent anti-inflammatory property of the ethyl acetate extract of soil strain of F. solani with a possible mechanism of action that involves the inhibition of COX enzyme.


Assuntos
Antibacterianos/farmacologia , Anti-Inflamatórios/farmacologia , Ciclo-Oxigenase 1/metabolismo , Inibidores de Ciclo-Oxigenase/farmacologia , Fusarium/química , Animais , Bacillus subtilis/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Camundongos , Pseudomonas aeruginosa/efeitos dos fármacos , Ratos , Salmonella typhi/efeitos dos fármacos , Microbiologia do Solo , Staphylococcus aureus/efeitos dos fármacos
14.
Mol Biotechnol ; 61(9): 633-649, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31177409

RESUMO

Galactose oxidase catalyzes a two-electron oxidation, mainly from the C6 hydroxyl group of D-galactose, with the concomitant reduction of water to hydrogen peroxide. This enzyme is secreted by Fusarium species and has several biotechnological applications. In this study, a screening of galactose oxidase production among species of the Fusarium fujikuroi species complex demonstrated Fusarium subglutinans to be the main producer. The truncated F. subglutinans gaoA gene coding for the mature galactose oxidase was expressed from the prokaryotic vector pTrcHis2B in the E. coli Rosetta™ (DE3) strain. The purified recombinant enzyme presented temperature and pH optima of 30 °C and 7.0, respectively, KM of 132.6 ± 18.18 mM, Vmax of 3.2 ± 0.18 µmol of H2O2/min, kcat of 12,243 s-1, and a catalytic efficiency (kcat/KM) of 9.2 × 104 M-1 s-1. In the presence of 50% glycerol, the enzyme showed a T50 of 59.77 °C and was stable for several hours at pH 8.0 and 4 °C. Besides D-(+)-galactose, the purified enzyme also acted against D-(+)-raffinose, α-D-(+)-melibiose, and methyl-α-D-galactopyranoside, and was strongly inhibited by SDS. Although the F. subglutinans gaoA gene was successfully expressed in E. coli, its endogenous transcription was not confirmed by RT-PCR.


Assuntos
Fusarium/enzimologia , Galactose Oxidase/metabolismo , Galactose/química , Proteínas Recombinantes/metabolismo , Sequência de Aminoácidos , Clonagem Molecular , Escherichia coli/genética , Escherichia coli/metabolismo , Fusarium/química , Galactose/metabolismo , Galactose Oxidase/química , Galactose Oxidase/genética , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Concentração de Íons de Hidrogênio , Melibiose/química , Melibiose/metabolismo , Metilgalactosídeos/química , Metilgalactosídeos/metabolismo , Modelos Moleculares , Oxirredução , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Rafinose/química , Rafinose/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Temperatura
15.
Biomed Chromatogr ; 33(9): e4574, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31062384

RESUMO

To develop an efficient method for large preparation of javanicin from Fusarium solani, a rapid and simple method by high-speed countercurrent chromatography was established based on average polarity (P' values) and partition coefficients (K values) of crude samples. A suitable solvent system for high-speed countercurrent chromatography was selected from many possible biphasic solvent systems. HSCCC was successfully applied to separate and purify javanicin, the main bioactive component of solid cultures of the fungus F. solani isolated from the fruiting body of Trametes trogii, with petroleum ether-ethyl acetate-methanol-water (4:3:2:1, v/v) as solvent system. A total amount of 40.6 mg of javanicin was obtained from 100 mg crude sample. The purity of javanicin was 92.2% with a recovery of 95.1%, as determined by high-performance liquid chromatrography. The molecular structure was identified primarily by NMR and MS methods. The results indicated that high-speed countercurrent chromatography could be a powerful technology for separating naphthoquinones from the solid cultures of the fungus F. solani. It is also of significance that the separation of javanicin from natural source was carried out for the first time utilizing high-speed countercurrent chromatography.


Assuntos
Distribuição Contracorrente/métodos , Carpóforos/química , Fusarium/química , Quassinas/isolamento & purificação , Solventes
16.
Org Biomol Chem ; 17(22): 5526-5532, 2019 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-31041978

RESUMO

Marine-derived fungi have been regarded as an under-explored and promising reservoir of structurally novel and bioactive natural products. In this study, five new γ-pyrone-containing polyketides, fusaresters A-E (1-5), were isolated and identified from the culture extracts of a marine-derived fungus Fusarium sp. Hungcl. The structures of compounds 1-5 were elucidated on the basis of their HRESIMS and NMR spectroscopic data as well as 13C NMR calculation and electronic circular dichroism (ECD) analyses. Remarkably, the structure of fusariumin D was revised to (9S*,11S*)-3. All these isolates were tested for the cytotoxicity against seven human cancer cell lines, including SW480, HL-60, A549, MCF-7, HepG2, HeLa and SMMC-7721, and the inhibitory activity against protein tyrosine phosphatase 1B (PTP1B). The results revealed that only compound 2 showed a weak inhibition rate of 56% at 40 µM.


Assuntos
Cumarínicos/química , Fusarium/química , Policetídeos/isolamento & purificação , Pironas/isolamento & purificação , Estrutura Molecular , Policetídeos/química , Pironas/química
17.
PLoS One ; 14(5): e0216735, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31071188

RESUMO

Fusarium graminearum is responsible for production of the mycotoxin deoxynivalenol (DON) on maize and wheat in Ontario, Canada. It has been understood since the early 1980s that in most parts of Canada, the predominant chemotype of F. graminearum is 15ADON, and not the 3ADON chemotype mainly found in Europe and Asia. The discovery of F. graminearum strains that did not produce DON but the structurally related 7-α hydroxy, 15-deacetylcalonectrin (3ANX) and its hydrolysis product 7-α hydroxy, 3,15-dideacetylcalonectrin to (NX) demonstrated that we still have a lot to learn about this well studied but complicated fungus. We conducted a survey of maize and wheat samples from Ontario farms. In the 2015 crop year, we isolated 86 strains and tested a representative subset of 20 using the published genetic probes for assessing genotype. We also developed a targeted LC-MS/MS method for the identification and quantitation of known toxins from this species to determine chemotype. The results showed that 80% of our strains produced some 3ANX in addition to 15ADON and one strain produced 3ANX and no 15ADON. Comparison of chemical data with genotyping revealed that in more than 50% of the cases there was no clear agreement. These data demonstrate the importance of chemical analysis for understanding the toxigenic potential of strains, especially using a LC-MS method that is capable of differentiating 3ADON and 15ADON. For this collection, genotyping of isolates did not produce reliable information on the chemotype. This is the first report of 3ANX toxin production concurrently with 15ADON and suggests that the 3ANX producers in North America likely originated from the 15ADON background.


Assuntos
Grão Comestível/microbiologia , Fusarium/química , Fusarium/genética , Vias Biossintéticas , Cromatografia Líquida , Fusarium/patogenicidade , Genótipo , Micotoxinas/análise , Micotoxinas/biossíntese , Ontário , Doenças das Plantas/microbiologia , Espectrometria de Massas em Tandem , Tricotecenos/análise , Tricotecenos/metabolismo , Triticum/microbiologia , Zea mays/microbiologia
18.
Poult Sci ; 98(7): 2964-2971, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30951601

RESUMO

The study showed that the hen housing system and egg storage conditions had significant influence on differences in the qualitative traits of eggs. The most rapid qualitative traits changes were observed in the eggs laid by the hens kept in the free-range and litter systems. After the first week of storage fungi were found on the eggshell surface but significant growth of fungi on the eggshell surface was noted after 3 wk, regardless of the storage conditions. Higher humidity during egg storage causes the dynamic development of fungi in the albumen. The principal component analysis proved the dependency between ergosterol and the trichothecene concentration in the albumen. Mycotoxins in the albumen indicate the presence of pathogenic species of microscopic fungi. The albumen of the eggs laid by the hens kept in cages had the lowest concentration of mycotoxins. The results of the study showed that the conditions of the henhouse environment significantly influenced the initial contamination of eggshells. Egg storage conditions, i.e., high air humidity, favor the development of fungi on the eggshell surface, affect the dynamics of fungal growth into the albumen and the production of mycotoxins.


Assuntos
Criação de Animais Domésticos/métodos , Ovos/microbiologia , Armazenamento de Alimentos/métodos , Micotoxinas/isolamento & purificação , Animais , Galinhas , Casca de Ovo/microbiologia , Ovos/análise , Feminino , Microbiologia de Alimentos , Qualidade dos Alimentos , Fungos/crescimento & desenvolvimento , Fungos/isolamento & purificação , Fusarium/química , Umidade , Micotoxinas/metabolismo
19.
Plant Dis ; 103(6): 1189-1195, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30964416

RESUMO

Brown marmorated stink bug (Halyomorpha halys Stål) is an invasive agricultural pest that causes severe damage to many crops. To determine potential associations between H. halys feeding damage, Fusarium infection, and mycotoxin contamination in field corn, a field survey was conducted in eight counties in Virginia. Results indicated an association between H. halys feeding damage and fumonisin contamination. Subsequent field experiments in Delaware, Maryland, and Virginia examined the ability of H. halys to increase Fusarium verticillioides (Sacc.) Nirenberg infection and fumonisin concentrations in corn. At the milk stage, H. halys (0 or 4 adults) and Fusarium (with or without F. verticillioides inoculum) treatments were applied to bagged ears in a two by two factorial randomized complete block design with 12 replicates. H. halys treatments increased levels of feeding damage (P < 0.0001) and Fusarium infection (P = 0.0380). Interaction between H. halys and Fusarium treatments influenced severity of infection (P = 0.0018) and fumonisin concentrations (P = 0.0360). Results suggest H. halys has the ability to increase both Fusarium infection and fumonisin concentrations in field corn. Further studies are needed to understand mechanisms by which H. halys increases fumonisin and to develop management strategies to mitigate impacts of H. halys on field corn in the region.


Assuntos
Fumonisinas , Fusarium , Hemípteros , Zea mays , Animais , Delaware , Fumonisinas/análise , Fusarium/química , Fusarium/fisiologia , Hemípteros/química , Hemípteros/microbiologia , Maryland , Virginia , Zea mays/química , Zea mays/microbiologia
20.
Zhongguo Zhong Yao Za Zhi ; 44(3): 460-464, 2019 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-30989908

RESUMO

In order to find new source of antifungal agents, eleven cultivable endophytic fungi were isolated from the roots,stems and leaves of Chelidonium majus by traditional method. Seven of them were identified as Colletotrichum(L1, L2, L3, S1, S3, S4, S5), and three of them were identified as Fusarium(R1,R2,R3) by morphological features and molecular biological technology. The antifungal activity test showed that all the tested fungi displayed some inhibitory activity against five common plant pathogens(C. gloeosporioides, Curvularia lunata, Pyricularia oryza, Alternaria alternate and A. brassicae), and their inhibition rate of some test items were over 60%. Among them, R1, S2, S3 and S4 were more potent than others. This study enriches the understanding of endophytes from Ch. majus and provides a basis for the study of new microbial fungicides.


Assuntos
Alternaria/patogenicidade , Ascomicetos/patogenicidade , Chelidonium/microbiologia , Colletotrichum/isolamento & purificação , Fusarium/isolamento & purificação , Antibiose , Colletotrichum/química , Endófitos/química , Endófitos/isolamento & purificação , Fusarium/química
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