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1.
J Agric Food Chem ; 67(38): 10646-10652, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31479255

RESUMO

A new monosesquiterpene diacetylgliocladic acid (1), a new dimeric sesquiterpene divirensol H (9), and two exceptionally novel trimeric sesquiterpene trivirensols A and B (11 and 12), together with another eight known congeners, were purified from an endophytic fungus Trichoderma virens FY06, derived from Litchi chinensis Sonn. whose fruit is a delicious and popular food. All of them were identified by comprehensive spectroscopic analysis, combined with biosynthetic considerations. Trivirensols A and B are unprecedented trimers of which three subunits are connected by two ester bonds of the sesquiterpene class. Relative to the positive control triadimefon, all the tested metabolites showed strong inhibitory activities against at least one phytopathogenic fungus among Penicillium italicum, Fusarium oxysporum, Fusarium graminearum, Colletotrichum musae, and Colletotrictum gloeosporioides. Notably, as metabolites of the endophytic fungus from L. chinensis, they all presented strong antifungal activities against C. gloeosporioides which causes anthracnose in L. chinensis.


Assuntos
Fungicidas Industriais/farmacologia , Litchi/microbiologia , Sesquiterpenos/farmacologia , Trichoderma/química , Colletotrichum/efeitos dos fármacos , Colletotrichum/crescimento & desenvolvimento , Endófitos/química , Endófitos/genética , Endófitos/isolamento & purificação , Endófitos/metabolismo , Frutas/microbiologia , Fungicidas Industriais/química , Fungicidas Industriais/metabolismo , Fusarium/efeitos dos fármacos , Fusarium/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Doenças das Plantas/microbiologia , Sesquiterpenos/química , Sesquiterpenos/metabolismo , Trichoderma/genética , Trichoderma/isolamento & purificação
2.
J Agric Food Chem ; 67(38): 10782-10790, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31490683

RESUMO

Systematic investigation of cyproconazole, including absolute stereochemistry, fungicidal activity, quantification in two matrixes, and stereoselective degradation in cucumber, are conducted in this study. By virtue of vibrational circular dichroism (VCD) spectroscopy, absolute configurations of four stereoisomers were identified to be (2R,3R)-(+)-, (2R,3S)-(+)-, (2S,3S)-(-)-, and (2S,3R)-(-)-cyproconazoles. Then four stereoisomers exhibited stereoselective fungicidal activities against Fusarium graminearum Schw and Magnaporthe oryzae, and the order of fungicidal activity was (2S,3S)-(-)-stereoisomer > the stereoisomer mixture > (2S,3R)-(-)-stereoisomer > (2R,3R)-(+)-stereoisomer > (2R,3S)-(+)-stereoisomer. Moreover, chiral liquid chromatography-tandem mass spectrometry was used to identify and quantify cyproconazole stereoisomers in soil and cucumber matrixes. Good linearity (R2 ≥ 0.99) and recoveries (86.79-92.47%, RSD ≤ 3.94%) for them were achieved, individually. Furthermore, stereoselective degradation of four cyproconazole stereoisomers was observed in cucumber and the order of degradation rate was (2R,3R)-(+)-cyproconazole > (2S,3S)-(-)-cyproconazole > (2R,3S)-(+)-cyproconazole > (2S,3R)-(-)-cyproconazole. We envision that such systematic assessments of chiral fungicides at an enantiomeric level would provide valuable information in future studies involving enantioselective physiological, metabolic, and toxicological activities.


Assuntos
Fungicidas Industriais/química , Triazóis/química , Alternaria/efeitos dos fármacos , Alternaria/crescimento & desenvolvimento , Cromatografia Líquida de Alta Pressão , Cucumis sativus/química , Contaminação de Alimentos/análise , Fungicidas Industriais/farmacologia , Fusarium/efeitos dos fármacos , Fusarium/crescimento & desenvolvimento , Rhizoctonia/efeitos dos fármacos , Rhizoctonia/crescimento & desenvolvimento , Poluentes do Solo/química , Poluentes do Solo/farmacologia , Estereoisomerismo , Espectrometria de Massas em Tandem , Triazóis/farmacologia
3.
J Agric Food Chem ; 67(41): 11403-11407, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31509401

RESUMO

Three new phenazine metabolites, strepphenazine A-C (1-3), along with a known compound baraphenazine E 4 were isolated from the culture broth of a Streptomyces strain YIM PH20095. The structures were elucidated based on the spectral data. Compounds 1-4 showed different antifungal activity against Fusarium oxysporum, Plectosphaerella cucumerina, Alternaria panax, and Phoma herbarum, which caused root-rot disease of Panax notoginseng with minimal inhibitory concentrations (MICs) of 16-64 µg/mL; compared with compound 4, compounds 1-3 showed better antifungal activity against some of these pathogenic fungi with MICs of 16-32 µg/mL, while compound 4 showed antifungal activity against F. oxysporum, P. cucumerina, and A. panax with the same MICs of 64 µg/mL. Thus, strain YIM PH20095 provides new sources for the development of biological control agents to prevent the infection of pathogenic fungi of P. notoginseng.


Assuntos
Antifúngicos/química , Antifúngicos/farmacologia , Panax notoginseng/microbiologia , Fenazinas/química , Fenazinas/farmacologia , Streptomyces/química , Alternaria/efeitos dos fármacos , Alternaria/crescimento & desenvolvimento , Antifúngicos/isolamento & purificação , Antifúngicos/metabolismo , Fusarium/efeitos dos fármacos , Fusarium/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Estrutura Molecular , Fenazinas/isolamento & purificação , Fenazinas/metabolismo , Doenças das Plantas/microbiologia
4.
J Agric Food Chem ; 67(31): 8536-8547, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31310520

RESUMO

Watermelon Fusarium wilt is a common soil-borne disease that has significantly affected its yield. In this study, fusaric acid-deficient mutant designated as ΔFUBT (mutated from Fusarium oxysporum f. sp. niveum, FON) was obtained. The ΔFUBT mutant showed significant decrease in fusaric acid production but maintained wild-type characteristics, such as in vitro colony morphology, size, and conidiation. A field pot experiment demonstrated that ΔFUBT could successfully colonize the rhizosphere and the roots of watermelon, leading to significant reduction in FON colonization in the watermelon plant. In addition, ΔFUBT inoculation significantly improved the rhizosphere microenvironment and effectively increased the resistance in watermelon. This study demonstrated that a nonpathogenic Fusarium mutant (ΔFUBT) could be developed as an effective microbial control agent to alleviate Fusarium wilt disease in watermelon and increase its yield.


Assuntos
Citrullus/microbiologia , Fusarium/genética , Micotoxinas/genética , Doenças das Plantas/microbiologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Ácido Fusárico/metabolismo , Fusarium/crescimento & desenvolvimento , Fusarium/fisiologia , Mutação , Micotoxinas/metabolismo , Raízes de Plantas/microbiologia , Rizosfera
5.
Int J Food Microbiol ; 305: 108242, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31176953

RESUMO

Fusarium meridionale and F. boothii cause Gibberella Ear Rot (GER) in maize. This study determined the effects of temperature (5-35 °C) and water activity (0.90-0.995 aw) on the growth, and deoxynivalenol (DON) and nivalenol (NIV) production of F. meridionale and F. boothii strains in maize grains. Fusarium graminearum sensu stricto strains from wheat were also tested. The three Fusarium species grew best at 0.995 aw and 25 °C. Growth was absent or marginal at 0.90 aw regardless of temperature. F. meridionale and F. boothii were sensitive to 30 °C and more affected by water stress than F. graminearum sensu stricto. The highest DON levels were at 0.995-0.97 aw and 30 °C and at 0.97 aw and 20 °C for F. graminearum sensu stricto, and at 0.995-0.97 aw and 20 °C for F. boothii. Fusarium meridionale reached maximum NIV accumulation at 0.995 aw and 20 °C. This produced DON at negligible levels compared to the other two Fusarium species. Growth of F. meridionale and F. boothii was well adapted to the usual autumn high humidity and mild temperatures associated with GER in northwest Argentina. Control strategies during grain development should be taken into account to reduce the risk of the presence of DON and NIV in the harvested grains.


Assuntos
Fusarium/metabolismo , Doenças das Plantas/microbiologia , Tricotecenos/metabolismo , Água/análise , Zea mays/microbiologia , Argentina , Fusarium/classificação , Fusarium/crescimento & desenvolvimento , Fusarium/isolamento & purificação , Umidade , Estações do Ano , Temperatura Ambiente , Tricotecenos/análise , Triticum/química , Triticum/microbiologia , Água/metabolismo , Zea mays/química
6.
J Sci Food Agric ; 99(13): 5760-5770, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31162844

RESUMO

BACKGROUND: It has been reported that antagonistic microorganisms could effectively control the infection of Fusarium graminearum. However, there is limited information on the control of F. graminearum by Saccharomyces cerevisiae, while the possible control mechanisms involved through proteomic and transcriptomic techniques have also not been reported. RESULTS: The results of this study showed that S. cerevisiae Y-912 could significantly inhibit the growth of F. graminearum Fg1, and the spore germination rate and germ tube length of F. graminearum Fg1 were also significantly inhibited by S. cerevisiae Y-912. Proteomic analysis revealed that differentially expressed proteins which were made of some basic proteins and enzymes related to basal metabolism, such as glyceraldehyde-3-phosphate dehydrogenase (GAPDH), phosphoglycerate mutase (PGAM), enolase (ENO), fructose diphosphate aldolase (FBA) and so on, were all down-regulated. The transcriptomics of F. graminearum control by S. cerevisiae was also analyzed. CONCLUSION: The control mechanism of S. cerevisiae Y-912 on F. graminearum Fg1 was a very complex material and energy metabolic process in which the related proteins and genes involved in the glycolytic pathway, tricarboxylic acid (TCA) cycle and amino acid metabolism were all down-regulated. © 2019 Society of Chemical Industry.


Assuntos
Fusarium/genética , Saccharomyces cerevisiae/genética , Transcriptoma , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fusarium/crescimento & desenvolvimento , Fusarium/metabolismo , Proteoma/genética , Proteoma/metabolismo , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/metabolismo , Esporos Fúngicos/genética , Esporos Fúngicos/crescimento & desenvolvimento , Esporos Fúngicos/metabolismo
7.
Microb Cell Fact ; 18(1): 89, 2019 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-31122261

RESUMO

BACKGROUND: Studies carried out with novel 13 strains of Trichoderma, isolated from mangrove sediments (PE, Brazil) using morphophysiological and molecular characterization, followed evaluation of biocontrol using Fusarium strains isolated from Caatinga soil (PE, Brazil). Trichoderma strains were characterized by polyphasic taxonomic approach, and the extracted DNA was amplified with primers ITS 1 and 4, and sequenced. The biocontrol evaluation was conducted at 24 and 48 h of growth intervals by Tukey test, with a significance of 5%. Antibiosis tests were assessed in vitro by dual plate and partition plate techniques against Fusarium strains. RESULTS: Trichoderma molecular identification, sequences of 500 bp were amplified, deposited into GenBank, and used for phylogenetic analyses. The strains were identified as T. asperellum (10), as T. harzianum (2) and one as T. longibrachiatum. Growth rate presented an average of 0.1207 cm h-1 for Trichoderma and lower growth rate of 0.031 cm h-1 for Fusarium spp., respectively. Antibiosis tests presented the best antagonist level of efficiency for T. asperellum UCP 0149 against F. solani UCP 1395 (82.2%) and F. solani UCP 1075 (70.0%), followed by T. asperellum UCP 0319 against F. solani UCP1083 (73.4%) and T. asperellum UCP 0168 against F. solani UCP1098 (71.5%), respectively. CONCLUSIONS: The data obtained in this study as tool for identification of novel Trichoderma strains serve as basis for development of several sustainable use for biotechnological processes. Those Trichoderma strains found promising for the management antagonistic potential and interaction could aid the conduct of biotechnological biocontrol of contaminants, and improve environmental conditions for the health of plants.


Assuntos
Antibiose , Agentes de Controle Biológico , Fusarium/crescimento & desenvolvimento , Plantas/microbiologia , Trichoderma/classificação , Áreas Alagadas , Biodiversidade , Brasil , Sedimentos Geológicos/microbiologia , Filogenia , Microbiologia do Solo , Trichoderma/genética , Trichoderma/isolamento & purificação
8.
Fungal Biol ; 123(5): 423-430, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31053331

RESUMO

Plant pathogens employ effectors as molecular weapons to manipulate host immunity and facilitate colonization. Fusarium oxysporum f. sp. cubense is the agent of wilt disease in banana plantlets and four races of the pathogen have been identified based on the cultivar specificity. A total of 9 SIX genes have been detected in the genome of Foc TR4 and 6 genes detected in Foc1. Among these SIX genes, SIX2 and SIX8 are only detected in Foc TR4, not identified in Foc1. Expression profiles analysis revealed that SIX genes of Foc TR4 are highly induced after inoculation to Cavendish banana plantlets. Virulence analysis of the SIX2 and SIX8 knock-out mutants showed that SIX8 is required for the virulence of Foc TR4 while SIX2 has no obvious functions. Over expression of SIX8-FLAG proteins in the SIX8 knock-out mutant partly restored the virulence. Western blot analysis suggested that SIX8 could be secreted into the extracellular space and a signal peptide resided the N-terminal polypeptide sequence. This study provides some clues for further research on mechanism of SIX8 in regulating virulence of Foc TR4.


Assuntos
Proteínas Fúngicas/metabolismo , Fusarium/patogenicidade , Musa/microbiologia , Doenças das Plantas/microbiologia , Fatores de Virulência/metabolismo , Proteínas Fúngicas/genética , Fusarium/genética , Fusarium/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Técnicas de Inativação de Genes , Teste de Complementação Genética , Fatores de Virulência/genética
9.
J Sci Food Agric ; 99(11): 5064-5072, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-30977147

RESUMO

BACKGROUND: Glyphosate (GP) is one of the main pesticides used for maize production. Fusarium sp. is a fungal genus with several phytopathogenic species and toxigenic features. In this study, the culturable soil mycota was evaluated using the surface-spray method. The effect of GP on the growth parameters (growth rate and lag phase) of Fusarium spp. was also tested on solid media conditioned with different water activities. Finally, the GP effect on disease severity caused by Fusarium sp. in maize seedlings was studied. RESULTS: The results showed that Fusarium species are frequently isolated from GP-exposed soils. The GP concentrations tested had a significant effect on F. graminearum, F. verticillioides and F. oxysporum growth parameters on solid media. The pathogenicity tests showed that the disease severity of the maize seedlings significantly increased with increasing GP concentrations. CONCLUSIONS: This study showed that Fusarium species are frequently isolated from pesticide-exposed soils and the GP concentrations tested had a significant effect both on growth parameters and disease severity in maize. This study provides an approach to the effect of GP on Fusarium sp. growth and pathogenicity that reinforces the importance of evaluating all the factors that could affect feed and food production. © 2019 Society of Chemical Industry.


Assuntos
Fungicidas Industriais/farmacologia , Fusarium/efeitos dos fármacos , Glicina/análogos & derivados , Doenças das Plantas/microbiologia , Zea mays/microbiologia , Fusarium/crescimento & desenvolvimento , Fusarium/fisiologia , Glicina/farmacologia , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/fisiologia
10.
Enzyme Microb Technol ; 126: 50-61, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31000164

RESUMO

The biocontrol activity of some soil strains of Chromobacterium sp. against pathogenic fungi has been attributed to secreted chitinases. The aim of this work was to characterize biochemically a recombinant chitinase (CvChi47) from C. violaceum ATCC 12472 and to investigate its effects on phytopathogenic fungi. CvChi47 is a modular enzyme with 450 amino acid residues, containing a type I signal peptide at the N-terminal region, followed by one catalytic domain belonging to family 18 of the glycoside hydrolases, and two type-3 chitin-binding domains at the C-terminal end. The recombinant enzyme was expressed in Escherichia coli as a His-tagged protein and purified to homogeneity. The native signal peptide of CvChi47 was used to direct its secretion into the culture medium, from where the recombinant product was purified by affinity chromatography on chitin and immobilized metal. The purified protein showed an apparent molecular mass of 46 kDa, as estimated by denaturing polyacrylamide gel electrophoresis, indicating the removal of the signal peptide. CvChi47 was a thermostable protein, retaining approximately 53.7% of its activity when heated at 100 °C for 1 h. The optimum hydrolytic activity was observed at 60 °C and pH 5. The recombinant chitinase inhibited the conidia germination of the phytopathogenic fungi Fusarium oxysporum and F. guttiforme, hence preventing mycelial growth. Furthermore, atomic force microscopy experiments revealed a pronounced morphological alteration of the cell surface of conidia incubated with CvChi47 in comparison to untreated cells. Taken together, these results show the potential of CvChi47 as a molecular tool to control plant diseases caused by these Fusarium species.


Assuntos
Antifúngicos/farmacologia , Quitinases/metabolismo , Chromobacterium/enzimologia , Fusarium/crescimento & desenvolvimento , Doenças das Plantas/prevenção & controle , Proteínas Recombinantes/metabolismo , Sequência de Aminoácidos , Domínio Catalítico , Quitinases/química , Quitinases/genética , Clonagem Molecular , Estabilidade Enzimática , Fusarium/efeitos dos fármacos , Doenças das Plantas/microbiologia , Conformação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Homologia de Sequência , Esporos Fúngicos/efeitos dos fármacos , Esporos Fúngicos/crescimento & desenvolvimento , Temperatura Ambiente
11.
Food Chem ; 289: 278-284, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-30955613

RESUMO

Fusarium rot of muskmelon is a common and frequently-occurring postharvest disease, which leads to quality deterioration and neosolaniol (NEO) contamination. New strategies to control postharvest decay and reduce NEO contamination are of paramount importance. The effects of acetylsalicylic acid (ASA) treatment on the growth of Fusarium sulphureum in vitro, and Fusarium rot development and NEO accumulation in fruits inoculated with F. sulphureum in vivo were investigated. The results showed that ASA inhibited the growth of F. sulphureum, evident morphological and major cellular changes were observed under the microscope. In vivo testing showed that 3.2 mg/mL ASA significantly suppressed Fusarium rot development and NEO accumulation after 6 and 8 d of pathogen inoculation. Meanwhile, Tri gene expressions involved in NEO biosynthesis were down-regulated after treatment. Taken together, ASA treatment not only reduced Fusarium rot development by inhibiting the growth of F. sulphureum, but decreased NEO accumulation by suppressing NEO biosynthesis pathway.


Assuntos
Aspirina/farmacologia , Cucurbitaceae/química , Tricotecenos/metabolismo , Cucurbitaceae/metabolismo , Cucurbitaceae/microbiologia , Frutas/química , Frutas/metabolismo , Frutas/microbiologia , Fusarium/efeitos dos fármacos , Fusarium/crescimento & desenvolvimento , Fusarium/metabolismo , Fusarium/ultraestrutura , Doenças das Plantas/prevenção & controle , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA de Plantas/genética , RNA de Plantas/metabolismo , Tricotecenos/química
12.
Braz J Microbiol ; 50(2): 481-494, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30877665

RESUMO

Fusarium crown and root rot (FCRR), caused by Fusarium oxysporum f. sp. radicis-lycopersici (FORL), is a soilborne tomato disease of increased importance worldwide. In this study, Withania somnifera was used as a potential source of biological control and growth-promoting agents. Seven fungal isolates naturally associated with W. somnifera were able to colonize tomato seedlings. They were applied as conidial suspensions or a cell-free culture filtrate. All isolates enhanced treated tomato growth parameters by 21.5-90.3% over FORL-free control and by 27.6-93.5% over pathogen-inoculated control. All tested isolates significantly decreased by 28.5-86.4% disease severity over FORL-inoculated control. The highest disease suppression, by 86.4-92.8% over control and by 81.3-88.8% over hymexazol-treated control, was achieved by the I6 isolate. FORL radial growth was suppressed by 58.5-82.3% versus control when dual cultured with tested isolates and by 61.8-83.2% using their cell-free culture filtrates. The most active agent was identified as Fusarium sp. I6 (MG835371), which displayed chitinolytic, proteolytic, and amylase activities. This has been the first report on the potential use of fungi naturally associated with W. somnifera for FCRR suppression and for tomato growth promotion. Further investigations are required in regard to mechanisms of action involved in disease suppression and plant growth promotion.


Assuntos
Antifúngicos/metabolismo , Agentes de Controle Biológico/metabolismo , Endófitos/metabolismo , Fusarium/crescimento & desenvolvimento , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/microbiologia , Doenças das Plantas/prevenção & controle , Withania/microbiologia , Amilases/metabolismo , Quitinases/metabolismo , Doenças das Plantas/microbiologia , Folhas de Planta/microbiologia , Raízes de Plantas/microbiologia , Caules de Planta/microbiologia , Proteólise
13.
J Sci Food Agric ; 99(9): 4338-4343, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30828809

RESUMO

BACKGROUND: Contamination of date fruit with mycotoxigenic fungi is a hazardous threat. The present study investigated the effectiveness of natural derivatives for controlling this. Chitosan (Cts) was produced from Aspergillus niger mycelia and characterized and then nanochitosan (NCt) particles were synthesized from fungal Cts. Edible-coating films were formulated based on Cts, NCt, pomegranate peel extract (PPE) and their composites and these were evaluated as antifungal materials against mycotoxigenic fungi, Aspergillus flavus, Aspergillus ochraceus and Fusarium moniliforme. RESULTS: The Cts produced had 88.7% deacetylation, a molecular weight of 24.5 kDa and 98% solubility in diluted acetic acid, whereas the particle diameters of synthesized NCts ranged from 35 to 65 nm. The inhibition zone assay emphasized the antifungal effectiveness of the entire coating films. The most effective agent for preparing edible film was the blend of NCt + PPE followed by Cts + PPE based films. The practical application of antifungal films for date decontamination with respect to mycotoxigenic fungi demonstrates that the films were very effective for controlling the entire fungal strain and preventing growth on the fruits. CONCLUSION: The NCt + PPE and Cts + PPE based films were found to be the most effective because they could completely eliminate the growth of any fungal spore on date fruit after 48 h from the coating experiment. © 2019 Society of Chemical Industry.


Assuntos
Biopolímeros/química , Embalagem de Alimentos/instrumentação , Frutas/microbiologia , Phoeniceae/microbiologia , Extratos Vegetais/química , Aspergillus flavus/efeitos dos fármacos , Aspergillus flavus/crescimento & desenvolvimento , Aspergillus niger/química , Aspergillus niger/metabolismo , Aspergillus ochraceus/efeitos dos fármacos , Aspergillus ochraceus/crescimento & desenvolvimento , Biopolímeros/metabolismo , Biopolímeros/farmacologia , Quitosana/química , Quitosana/metabolismo , Quitosana/farmacologia , Contaminação de Alimentos/análise , Contaminação de Alimentos/prevenção & controle , Frutas/química , Fusarium/efeitos dos fármacos , Fusarium/crescimento & desenvolvimento , Phoeniceae/química , Extratos Vegetais/farmacologia
14.
Curr Microbiol ; 76(8): 930-938, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30859289

RESUMO

Phenolic (free, conjugated and bound) and carotenoid extracts from microalgae Nannochloropsis sp. and Spirulina sp. were investigated regarding their potential to mitigate contamination by Fusarium complex fungal pathogens. Free phenolic acid extracts from both microalgae were the most efficient, promoting the lowest mycelial growth rates of 0.51 cm day- 1 (Spirulina sp.) and 0.78 cm day- 1 (Nannochloropsis sp.). An experiment involving natural free phenolic acid extracts and synthetic solutions was carried out based on the natural phenolic acid profile. The results revealed that the synthetic mixtures of phenolic acids from both microalgae were less efficient than the natural extracts at inhibiting fungal growth, indicating that no purification is required. The half-maximal effective concentration (EC50) values of 49.6 µg mL- 1 and 33.9 µg mL- 1 were determined for the Nannochloropsis and Spirulina phenolic acid extracts, respectively. The use of phenolic extracts represents a new perspective regarding the application of compounds produced by marine biotechnology to prevent Fusarium species contamination.


Assuntos
Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Fusarium/efeitos dos fármacos , Fusarium/crescimento & desenvolvimento , Spirulina/química , Estramenópilas/química , Misturas Complexas/isolamento & purificação , Misturas Complexas/farmacologia , Micélio/efeitos dos fármacos , Micélio/crescimento & desenvolvimento
15.
Microb Pathog ; 130: 232-241, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30851361

RESUMO

Biofilms are structures that confer adaptive ability to and facilitate the virulence of fungal pathogens. Certain multi-functional proteins have been shown to be involved in fungal pathogenesis and these proteins may also be implicated in biofilm formation. The aim of this study was to identify a fungal agent isolated from the human cornea, to analyze the ability of this organism to form biofilms in vitro and to investigate protein expression in this condition. The fungus was identified by phylogenetic inference analysis. Biofilm formation and structure were evaluated by colorimetric methods and by optical and electron microscopy. We also resolved proteins obtained from biofilms and planktonic cultures by two-dimensional gel electrophoresis and identified those proteins by mass spectrometry. The fungus was identified as Fusarium falciforme. Colorimetric analysis and microscopy revealed that the highest level of biofilm formation was obtained at a concentration of 1 × 106 conidia/mL with 96 h of incubation at 28 °C. The biofilm architecture consisted of an extracellular matrix that embedded fungal filaments. We found nineteen proteins that were over-expressed in biofilms, as compared with planktonic cultures, and six proteins with unique expression in biofilms. Among the more abundant proteins identified were: transketolase, a putative antigen 1, enolase, phosphoglycerate kinase and ATP-citrate synthase. Some of these proteins are involved in basal metabolism, function as multi-functional proteins or have been described as potential virulence factors. We focused on the expression in biofilm of the enzyme, enolase, which was determined by real-time PCR. Our findings provide a perspective on the proteins associated with the formation of biofilms in vitro by an F. falciforme keratitis isolate.


Assuntos
Biofilmes/crescimento & desenvolvimento , Proteínas Fúngicas/análise , Fusarium/química , Fusarium/crescimento & desenvolvimento , Proteoma/análise , Córnea/microbiologia , Eletroforese em Gel Bidimensional , Infecções Oculares Fúngicas/microbiologia , Fusariose/microbiologia , Fusarium/isolamento & purificação , Humanos , Ceratite/microbiologia , Espectrometria de Massas
16.
Phytopathology ; 109(6): 993-1002, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30714884

RESUMO

Characteristics or constituents of plant-associated microbiomes may assist in constraining disease development. To investigate this possibility for the wheat-Fusarium head blight pathosystem, we assessed seed weight, pathogen load, deoxynivalenol content, and microbiome profiles for individual wheat kernels collected over 2 years from a disease-conducive environment. We found that the microbiomes of individual, hulled wheat kernels consist of dozens to greater than a hundred bacterial taxa and up to several dozen fungal taxa, and that year-to-year variation in microbiome structure was large. Measures of microbial community diversity were negatively correlated with measures of disease severity, and had significant power to explain variation in pathogen load among seeds. Several operational taxonomic units belonging to the genus Sphingomonas demonstrated particularly strong negative relationships with pathogen load. This study illuminates the composition of microbiomes associated with wheat kernels under disease-conducive field conditions, and suggests relationships between microbiome characteristics and Fusarium head blight that warrant further study.


Assuntos
Fusarium , Tricotecenos , Fusarium/crescimento & desenvolvimento , Doenças das Plantas/microbiologia , Triticum/microbiologia
17.
Int Microbiol ; 22(2): 289-296, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30810992

RESUMO

Wheat gluten proteins are decisive for the industrial properties of flour, so alterations resulting from grain infection with Fusarium graminearum produce changes in the glutenin content that affect the baking properties. This work analyzes the high-molecular-weight glutenin changes from wheat flour with different degrees of F. graminearum infection at field, since these proteins are determinant for the quality properties of flour. Wheat cultivars-on field trials-infected with F. graminearum isolates of diverse aggressiveness showed severity values between 9.1 and 42.58% and thousand kernel weight values between 28.12 and 32.33 g. Negative correlations between severity and protein content and positive correlations between yield and protein content were observed, employing reversed-phase high-performance liquid chromatography and polyacrylamide gel electrophoresis. Furthermore, the protein signal changes were in agreement for both methodological approaches. Also, the degree of disease observed and the protein changes on infected wheat cultivars varied in relation with the aggressiveness of the isolate responsible for the infection. The principal component analysis showed a close arrangement among protein values obtained by HPLC. For each cultivar, two principal components were obtained, which explained 80.85%, 88.48%, and 93.33% of the total variance (cultivars Sy200, AGP Fast, and Klein Tigre respectively). To our knowledge, the approaches employed for the analysis of protein changes according to the degree of disease, as well as the thorough statistical analysis, are novel for the study of Fusarium Head Blight.


Assuntos
Fusarium/crescimento & desenvolvimento , Fusarium/metabolismo , Glutens/análise , Doenças das Plantas/microbiologia , Proteínas de Plantas/análise , Triticum/química , Triticum/microbiologia , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Farinha/análise
18.
Microbiol Res ; 220: 1-11, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30744814

RESUMO

Continuous monocropping often influences negatively the soil microbial community and leads to the occurrence of soil-borne diseases. In this study, a pre-cultivation soil management strategy, reductive soil disinfestation (RSD), involving amendment by the use of reed straw, bagasse, and rice straw, and creating anaerobic soil conditions, was used to regulate the microbial community in a soil infested by Fusarium wilt of lisianthus and make it suitable for plant cultivation. The results showed that RSD significantly decreased F. oxysporum population by 97.1%-99.1% and the incidence of lisianthus wilt disease to 3.0%-14.3% compared with that of the untreated soil. The lowest disease incidence was found in the soil treated with RSD where bagasse was incorporated. The replantation of the host plant differently stimulated the pathogen proliferations across the different soils. MiSeq sequencing and culture-dependent investigation showed that the RSD treatments established distinct microbial communities compared to that of the untreated soil. Furthermore, the relative abundances of representatives of the families Cytophagaceae, Chitinophagaceae, Chaetomiaceae, and an unclassified family within Sordariomycetes, as well as soil microbial activity and the proportions of antagonists were significantly and negatively correlated with the pathogen population increase. Overall, the RSD treatment contributed to the reassembly of the soil microbiome which contained more beneficial agents that successfully controlled the pathogen inoculum level and lisianthus Fusarium wilt disease.


Assuntos
Antibiose/fisiologia , Fusariose/prevenção & controle , Fusarium/patogenicidade , Microbiota/fisiologia , Microbiologia do Solo , Ascomicetos/genética , Bactérias , China , DNA Bacteriano/análise , Fusarium/crescimento & desenvolvimento , Microbiota/genética , Oryza , Doenças das Plantas/microbiologia , Análise de Sequência de DNA , Solo/química
19.
Mycopathologia ; 184(2): 303-308, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30734128

RESUMO

Fusarium petroliphilum is a recently described species within the Fusarium solani species complex. Some strains of Fusarium species are capable of forming yeast-like structures in tissue as well as in culture through a process known as "adventitious sporulation." Here, we describe the formation of these yeast-like reproductive structures in infected nail tissue obtained from a case of onychomycosis. These structures were also observed in culture grown on RPMI 1640 agar supplemented with 2% glucose. The isolate was resistant to azoles and echinocandins. To the best of our knowledge, this is the first report describing adventitious sporulation in F. petroliphilum and its etiologic role in onychomycosis.


Assuntos
Fusariose/microbiologia , Fusarium/crescimento & desenvolvimento , Onicomicose/microbiologia , Esporos Fúngicos/crescimento & desenvolvimento , Meios de Cultura/química , Humanos , Unhas/microbiologia
20.
Molecules ; 24(4)2019 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-30795501

RESUMO

A rapid and convenient biochemometrics-based analysis of several cereal-derived extracts was used to identify n-alkyl(enyl)resorcinols (AR) as antifungals against Fusarium oxysporum. Total AR content and liquid chromatography/mass spectrometry (LC-MS)-based profiles were recorded for each extract, in addition to their antifungal activity, to help integrate these chemical and biological datasets by orthogonal partial least squares regression. In this study, we developed and used a micro-scale amended medium (MSAM) assay to evaluate the in vitro mycelial growth inhibition at low amounts of extracts. Triticale husk-derived extracts had the highest AR content (662.1 µg olivetol equivalent/g dry extract), exhibiting >79% inhibition at the highest doses (10.0⁻1.0 µg/µL). Correlation of the chemical and antifungal datasets using supervised metabolite profiling revealed that 5-n-nonadecanylresorcinol, 5-n-heneicosylresorcinol, and 5-n-tricosyl-resorcinol were the most active ARs occurring in cereal products from Colombia. Hence, we propose the biochemometrics-based approach as a useful tool for identifying AR-like antifungals against F. oxysporum.


Assuntos
Antifúngicos/metabolismo , Grão Comestível/metabolismo , Fusarium/efeitos dos fármacos , Micélio/efeitos dos fármacos , Resorcinóis/metabolismo , Antifúngicos/química , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Cromatografia Líquida/métodos , Cromatografia Líquida/estatística & dados numéricos , Grão Comestível/imunologia , Grão Comestível/microbiologia , Fusarium/crescimento & desenvolvimento , Humanos , Análise dos Mínimos Quadrados , Metaboloma/imunologia , Testes de Sensibilidade Microbiana , Micélio/crescimento & desenvolvimento , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Extratos Vegetais/química , Resorcinóis/química , Resorcinóis/isolamento & purificação , Resorcinóis/farmacologia , Espectrometria de Massas em Tandem/métodos , Espectrometria de Massas em Tandem/estatística & dados numéricos
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