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1.
Braz J Microbiol ; 54(4): 2651-2661, 2023 Dec.
Article de Anglais | MEDLINE | ID: mdl-37642890

RÉSUMÉ

Endophytic fungi produce a range of known metabolites and several others, not yet explored, which present important biological activities from the pharmaceutical and industrial perspective. Several studies have reported the diversity of endophytes in Coffea arabica plants, although few have been described in organic cultures. In the current paper, we describe the chemical profile of specialized metabolites in the ethyl acetate phase in a strain of the endophytic fungus Colletotrichum siamense associated with coffee (Coffea arabica L.) (Rubiaceae) and its potential against tumor cells and bacteria of medical and food importance. Cytotoxicity assays in tumor cells MCF-7 and HepG2/C3A were performed by MTT and microdilution in broth to evaluate the antibacterial action of metabolic extract. The antiproliferative assay showed promising results after 24 h of treatment, with 50% injunction concentrations for the two cell types. UHPLC-MS/MS analyses with an electrospray ionization source were used to analyze the extracts and identify compounds of species Colletotrichum siamense, which is still little explored as a source of active metabolites. Many of these compounds observed in the endophytic need to be chemically synthesized in industry, at high costs, while production by the fungus becomes a chemically and economically more viable alternative. Pyrocatechol, gentisyl alcohol, and alpha-linolenic acid, associated with different mechanisms of action against tumor cells, were detected among the main compounds. The extract of the endophytic fungus Colletotrichum siamense presented several compounds with pharmacological potential and antibacterial activity, corroborating its potential in biotechnological applications.


Sujet(s)
Coffea , Colletotrichum , Coffea/microbiologie , Café/métabolisme , Spectrométrie de masse en tandem , Antibactériens/pharmacologie , Antibactériens/métabolisme , Extraits de plantes/pharmacologie , Extraits de plantes/métabolisme , Endophytes
2.
Chemosphere ; 340: 139956, 2023 Nov.
Article de Anglais | MEDLINE | ID: mdl-37640209

RÉSUMÉ

The incorrect disposal of textile dyes, such as Reactive Black 5 (RB5), causes several problems for living beings and the quality of the environment. Nanobiocomposites (NBC) produced from endophytic fungi (potentially remediation dyes-agents) and magnetic nanoparticles have high biotechnological potential due to their superparamagnetic behavior, which would allow their recovery through the magnetic field after the bioremediation process. This work aimed to obtain a new nanobiocomposite from the interaction of magnetite nanoparticles (Fe3O4) with the endophyte Aspergillus flavus (Af-CL-7) to evaluate its bioremediation capacity and to reduce the toxicity of RB5 and its reuse. Before obtaining the NBC, Af-CL-7 showed discoloration of RB5 and it was tolerant to all tested concentrations of this dye. The discovery of the nanobiocomposite textile dye bioremediator product presents a significant environmental advantage by addressing the issue of water pollution caused by textile dyes. The NBC called Af-Fe3O4 was successfully obtained with the magnetized endophyte, and their magnetic properties were verified by VSM analysis and by action of magnetic fields generated by Nd-Fe-B magnets SEM analyzes showed that the nanoparticles did not cause any damage to the hypha morphology, and TEM analyzes confirmed the presence of nanoparticles in the fungus wall and also inside the cell. The NBC Af-Fe3O4 and Af-CL-7 showed, respectively, 96.1% and 92.2% of RB5 discoloration in the first use, 91.1% e 86.2% of discoloration in the validation test, and 89.0% in NBC reuse. In the toxicological bioassay with Lactuca sativa seeds, NBC showed a positive reduction in the toxicity of RB5 after treatment, allowing the hypocotyl growth to be statistically similar to the control with water. Thus, we highlight the promising obtaining process of NBC that could be applied in bioremediation of contaminated waters, wherein the industrial economic cost will depend on the fermentation efficiency, biomass production and nanoparticle synthesis.


Sujet(s)
Aspergillus flavus , Nanoparticules de magnétite , Dépollution biologique de l'environnement , Champignons , Agents colorants , Endophytes
3.
Mycology ; 13(4): 257-270, 2022.
Article de Anglais | MEDLINE | ID: mdl-36405335

RÉSUMÉ

The protective and growth-promoting activities of Colletrotrichum and Diaporthe endophytes on tomato plants (Lycopersicon esculentum Mill.) are underexplored. We screened 40 endophytic fungi associated with Mexican shrimp plant (Justicia brandegeana) using an in vitro dual culture assay for Fusarium oxysporum, one of the most important phytopathogens of tomato plants. The three best antagonists, Colletotrichum siamense (JB224.g1), C. siamense (JB252.g1), and Diaporthe masirevicii (JB270), were identified based on multilocus sequence analysis. They were assessed in vitro for their inhibition of F. oxysporum and phosphate solubilisation capacity, and for the production of indole acetic acid. Greenhouse experiments verified the growth-promoting effects of these endophytes and the suppression of F. oxysporum symptoms in tomato plants.   Under greenhouse conditions, the JB252.g1 and JB270 isolates showed positive results for seedling emergence speed. The radicular system depth of plants inoculated with JB270 was greater than that in uninoculated plants (27.21 vs 21.95 cm). The soil plant analysis development chlorophyll metre (SPAD) index showed statistically significant results, especially for the endophyte JB224.g1 (36.99) compared to the control plants (30.90) and plants infected solely with F. oxysporum (33.64).

4.
Metabolites ; 12(8)2022 Jul 26.
Article de Anglais | MEDLINE | ID: mdl-35893260

RÉSUMÉ

Endophytic microorganisms show great potential for biotechnological exploitation because they are able to produce a wide range of secondary compounds involved in endophyte−plant adaptation, and their interactions with other living organisms that share the same microhabitat. Techniques used to chemically extract these compounds often neglect the intrinsic chemical characteristics of the molecules involved, such as the ability to form conjugate acids or bases and how they influence the solubilities of these molecules in organic solvents. Therefore, in this study, we aimed to evaluate how the pH of the fermented broth affects the process used to extract the secondary metabolites of the Diaporthe citri strain G-01 endophyte with ethyl acetate as the organic solvent. The analyzed samples, conducted by direct-infusion electrospray-ionization mass spectrometry, were grouped according to the pH of the fermented broth (i.e., <7 and ≥7). A more extreme pH (i.e., 2 or 12) was found to affect the chemical profile of the sample. Moreover, statistical analysis enabled us to determine the presence or absence of ions of high importance; for example, ions at 390.7 and 456.5 m/z were observed mainly at acidic pH, while 226.5, 298.3, and 430.1 m/z ions were observed at pH ≥ 7. Extraction at a pH between 4 and 9 may be of interest for exploring the differential secondary metabolites produced by endophytes. Furthermore, pH influences the chemical phenotype of the fungal metabolic extract.

5.
Nat Prod Res ; 36(12): 3158-3162, 2022 Jun.
Article de Anglais | MEDLINE | ID: mdl-34227409

RÉSUMÉ

This study was to evaluate the biological activity of the extract of Botryosphaeria fabicerciana isolated from leaves of Morus nigra. The volatile compounds from the crude extract were analysed by GC-MS which demonstrate that mellein and ß-orcinaldehyde were are the major compounds. The best minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extract was observed against Gram-positive bacteria, with a MIC of 15.6 µg/mL towards B. cereus and MIC of 62.5 µg/mL towards S. aureus and B. subtilis. MBC values of 31.25 µg/mL, 62.5 µg/mL, and 250 µg/mL were observed towards B. cereus, B. subtilis, and S. aureus, respectively. The cytotoxicity analyses showed CC50 of 115 µg/mL. The crude extract showed antioxidant activity by the DPPH, ABTS, and FRAP assays. Therefore, the extract of the endophytic fungus presented biotechnological potential as an antibacterial and antioxidant agent.


Sujet(s)
Anti-infectieux , Ascomycota , Morus , Antibactériens/composition chimique , Anti-infectieux/pharmacologie , Antioxydants/composition chimique , Ascomycota/métabolisme , Bactéries/métabolisme , Tests de sensibilité microbienne , Morus/métabolisme , Extraits de plantes/composition chimique , Staphylococcus aureus/métabolisme
6.
Braz J Microbiol ; 52(4): 2179-2192, 2021 Dec.
Article de Anglais | MEDLINE | ID: mdl-34491570

RÉSUMÉ

The composition of endophytic communities is dynamic and demonstrates host specificity; besides, they have great intra- and interspecific genetic variability. In this work, we isolated leaf endophytic fungi from Serjania laruotteana, identify them using multilocus analysis, and evaluate the genetic variability using IRAP (inter-retrotransposon amplified polymorphism) and REMAP (retrotransposon-microssatellite amplified polymorphism). A total of 261 fungi were isolated and 58 were identified. Multilocus phylogenetic analysis using the partial sequences from the ITS1-5.8S-ITS2 regions, elongation factor 1-alpha, ß-tubulin, actin, glyceraldehyde-3-phosphate dehydrogenase, and calmodulin genes identify that most strains belonged to the Colletotrichum and Diaporthe genera, other isolated genera were Xylaria, Phyllosticta, Muyocopron, Fusarium, Nemania, Plectosphaerella, Corynespora, Bipolaris, and Curvularia. The IRAP and REMAP analyzes were performed with Colletotrichum and Diaporthe genera and showed 100% of polymorphism and high intra- and interspecific variability. This is the first report of the diversity of endophytic fungi from S. laruotteana. In addition, it demonstrated that the IRAP and REMAP can be used to distinguish morphologically similar lineages, revealing differences even strains of the same species.


Sujet(s)
Biodiversité , Champignons , Sapindaceae , Champignons/classification , Champignons/génétique , Typage par séquençage multilocus , Phylogenèse , Rétroéléments/génétique , Sapindaceae/microbiologie
7.
Nat Prod Res ; 35(21): 4148-4153, 2021 Nov.
Article de Anglais | MEDLINE | ID: mdl-32174195

RÉSUMÉ

In the present study, the biological activity of an extract of the secondary metabolites (E-G6-32) produced by the Curvularia sp. G6-32 endophyte (isolated from the medicinal plant Sapindus saponaria L.) was investigated. The antioxidant potential was confirmed by the DPPH (22.5%) and ABTS (62.7%) assays, and the total phenolic compound content was 40 µg gallic acid equivalents/mg. The extract E-G6-32 displayed good inhibitory activity toward butyrylcholinesterase (BuChE; IC50 = 110 ± 0.05 µg mL-1). The extract E-G6-32 was subjected to spectroscopic and mass spectrometry analyses. Comparison with the literature data confirmed that (-)-asperpentyn (1) was a major component. Asperpentyn belongs to the epoxyquinone family, which has attractive structural complexity, diverse functional groups, and a broad range of biological activities, including specific enzyme inhibitory activity. Our results suggest that Curvularia sp. G6-32 is a promising source of bioactive secondary metabolites and contains (-)-asperpentyn, which has potential pharmaceutical interest.[Figure: see text].


Sujet(s)
Antioxydants/pharmacologie , Anticholinestérasiques/pharmacologie , Curvularia (genre)/composition chimique , Sapindus , Butyrylcholine esterase , Endophytes/composition chimique , Sapindus/microbiologie , Métabolisme secondaire
8.
Int J Food Microbiol ; 338: 109019, 2021 Jan 02.
Article de Anglais | MEDLINE | ID: mdl-33310341

RÉSUMÉ

In this work, the antibacterial activity of a crude extract of the endophytic fungus Flavodon flavus (JB257), isolated from leaves of Justicia brandegeana, was evaluated against both the vegetative and sporulated forms of Alicyclobacillus acidoterrestris. The microdilution technique was performed in order to determine the antibacterial activity of the crude extract alone as well as in combination with the bacteriocin, nisin. The minimum inhibitory concentration (MIC) of the crude extract and nisin alone against A. acidoterrestris vegetative forms were 250 µg/mL and 31.5 µg/mL, respectively, while the minimum bactericidal concentrations (MBC) were 1000 µg/mL and 62.5 µg/mL,respectively. For A. acidoterrestris spores, treatment with the crude extract at a concentration of 500 µg/mL caused a 47% reduction in growth, while nisin at 62.5 µg/mL could reduce 100% of the growth. The in vitro evaluation of the crude extract combined with nisin against A. acidoterrestris by the Checkerboard method showed a synergistic interaction between the two compounds. In addition, greater selectivity towards bacterial cells over host cells, a human hepatocyte cell line, was achieved when the crude extract was combined with nisin, Using scanning electron microscopy, interferences in the cell membrane of A. acidoterrestris could be observed after treatment with the crude extract. The results presented in this study indicate that the crude extract of the endophyte F. flavus has biotechnological potential in the food industry, especially for the treatment of orange juices through the control of A. acidoterrestris.


Sujet(s)
Alicyclobacillus/effets des médicaments et des substances chimiques , Citrus sinensis/microbiologie , Microbiologie alimentaire/méthodes , Jus de fruits et de légumes/microbiologie , Adhatoda/composition chimique , Adhatoda/microbiologie , Polyporales/composition chimique , Antibactériens/pharmacologie , Tests de sensibilité microbienne , Nisine/pharmacologie
9.
Acta sci., Biol. sci ; 43: e51737, 2021. tab, ilus
Article de Anglais | LILACS, VETINDEX | ID: biblio-1460974

RÉSUMÉ

Endophytes are growth-promoting agents capable of synthesizing phytohormones, uptaking nutrients, and controlling pathogens. There is a strong potential to exploit them in the agriculture field like biofertilizers and biocontrol agents. In this work, we aimed to evaluate endophytic fungi isolated from Pachystachys lutea for their potential to solubilize phosphate, synthesise indole acetic acid (IAA), antagonize phytopathogens, and promote plant growth under greenhouse conditions. The phosphate solubilization efficiency was assessed on Pikovskaya’s agar medium. For analysis of IAA production, mycelia plugs of endophytes were cultured in Potato Dextrose Broth medium supplemented with L-tryptophan, with Salkowski Reagent, and the absorbance of the culture was measured. The antagonism evaluation of strain Alternaria sp. PL75 against phytopathogens was performed using the paired-culture technique. The promotion of plant growth provided by Alternaria sp. PL75 was evaluated in tomato plants. All strains evaluated were able to solubilize phosphate; however, the strain Alternaria sp. PL75 was the most effective (4.29). Two strains, Nemania sp. PL27 and Alternaria sp. PL75, produced 1.86 and 1.73 & 956;g mL-1 of IAA, respectively. In the antagonism assay, the endophyte Alternaria sp. PL75 and its fungal extract showed the best results against the pathogen Moniliophthora perniciosa. The greenhouse experiment result showed the endophyte Alternaria sp. PL75 increased the plantlets emergency speed index and the percentage of germination from 60 to 81.63%. It was also observed a statistical significance in the shoot length of the treated plants with the endophyte suspension (55.38 cm) compared to the control (41.67 cm).


Sujet(s)
Endophytes , Phosphates , Lamiales/croissance et développement , Acide acétique/analyse
10.
Biosci. j. (Online) ; 36(5): 1742-1749, 01-09-2020. tab, graf
Article de Anglais | LILACS | ID: biblio-1147925

RÉSUMÉ

We have previously reported that ß-(1→3,1→6)-ᴅ-glucans produced by endophytes Diaporthe sp. G27-60 and G65-65 (GenBank accession codes JF766998 and JF767007, respectively) are promising anti-proliferation agents against human breast carcinoma (MCF-7) and hepatocellular carcinoma (HepG2-C3A) cells. However, the literature fails to describe the effects of Diaporthe exopolysaccharides (EPS) on eukaryotic healthy cells. The fungus Metarhiziumanisopliae has been employed as model-system to evaluate the toxicity of pharmaceutical and agricultural-interest substances, taking into account, among other parameters, the speed of conidia germination. Current study verified the effect of different concentrations of Diaporthe ß-glucans on the germination speed of M. anisopliae. Conidia were incubated with ß-glucans treatments (50, 200 and 400 µg/mL) at 28ºC, sampled during 24 h and analyzed by light microscopy. At the end of a 24-h incubation, the amount of germinated conidia reached ≈99% for controls and ranged between 97.7 and 98.6% for treatments. Bayesian analysis indicated that Diaporthe glucans had no toxicity on M. anisopliaeand the curve of germination occurred as expected for this fungal strain. Considering the validity of filamentous fungi as model-systems, results are important data on the toxicity of endophytic EPS on healthy cells and may be associated with our previous results obtained for these polymers against tumor cells.


Anteriormente, um estudo mostrou que ß-(1→3,1→6)-ᴅ-glucanas produzidas pelos endófitos Diaporthe sp. G27-60 e G65-65 (códigos de acesso no GenBank JF766998 e JF767007, respectivamente) são agentes promissores com ação antiproliferativa contra células HepG2-C3A (hepatoma humano) e MCF-7 (adenocarcinoma mamário humano). No entanto, os efeitos de exopolissacarídeos (EPS) produzidos por fungos do gênero Diaporthe em células eucarióticas sadias não estão descritos na literatura atual. O fungo Metarhiziumanisopliae tem sido utilizado como sistema-modelo para avaliar a toxicidade de substâncias de interesse farmacêutico e agronômico, considerando, entre outros parâmetros, a velocidade de germinação de conídios. O presente estudo teve como objetivo verificar os efeitos de diferentes concentrações de ß-glucanas produzidas por Diaporthe sp. sobre a velocidade de germinação de M. anisopliae. Os conídios foram incubados com os tratamentos de ß-glucanas (50, 200 e 400 µg/mL) a 28 ºC, com amostras coletadas ao longo de 24 h, e analisados por microscopia de luz. Ao final das 24 h de incubação, o total de conídios germinados nos controles foi de ≈99%, e variou entre 97,7 e 98,6% para os tratamentos. A análise bayesiana indicou que as glucanas de Diaporthe sp. não apresentaram toxicidade sobre M. anisopliae, e a curva de germinação atendeu ao esperado para essa linhagem fúngica. Considerando a validade dos fungos filamentosos como sistemas-modelo, esses resultados representam dados importantes sobre a toxicidade dos EPS de endófitos sobre células sadias e podem ser associados aos resultados anteriormente obtidos para esses polímeros em testes contra células tumorais.


Sujet(s)
Théorème de Bayes , Endophytes , Champignons
11.
Braz J Microbiol ; 51(2): 557-569, 2020 Jun.
Article de Anglais | MEDLINE | ID: mdl-31872390

RÉSUMÉ

Endophytes are microorganisms that form symbiotic relationships with their own host. Included in this group are the species Phyllosticta capitalensis, a group of fungi that include saprobes that produce bioactive metabolites. The present study aimed to identify the cultivable endophytic fungal microbiota present in healthy leaves of Tibouchina granulosa (Desr.) Cogn. (Melastomataceae) and investigate secondary metabolites produced by a strain of P. capitalensis and their effects against both Leishmania species and Trypanossoma cruzi. Identification of the strains was accomplished through multilocus sequencing analysis (MLSA), followed by phylogenetic analysis. The frequency of colonization was 73.66% and identified fungi belonged to the genus Diaporthe, Colletotrichum, Phyllosticta, Xylaria, Hypoxylon, Fusarium, Nigrospora, and Cercospora. A total of 18 compounds were identified by high-resolution mass spectrum analysis (UHPLC-HRMS), including fatty acids based on linoleic acid and derivatives, from P. capitalensis. Crude extracts had activity against Leishmania amazonensis, L. infantum, and Trypanosoma cruzi, with inhibitory concentration (IC50) values of 17.2 µg/mL, 82.0 µg/mL, and 50.13 µg/mL, respectively. This is the first report of the production of these compounds by the endophytic P. capitalensis isolated from T. granulosa.


Sujet(s)
Antiprotozoaires/pharmacologie , Ascomycota/composition chimique , Ascomycota/isolement et purification , Melastomataceae/microbiologie , Animaux , Antiprotozoaires/isolement et purification , Ascomycota/classification , Endophytes/composition chimique , Endophytes/classification , Endophytes/isolement et purification , Leishmania/effets des médicaments et des substances chimiques , Tests de sensibilité microbienne , Métabolisme secondaire , Trypanosoma/effets des médicaments et des substances chimiques
12.
Acta sci., Biol. sci ; 42: e48321, fev. 2020. tab, graf, ilus
Article de Anglais | LILACS, VETINDEX | ID: biblio-1460938

RÉSUMÉ

Endophytic microorganisms live inside the plants without causing any damage to their hosts. In the agricultural field, these endophytes might be a strategy of biological control for phytopathogens. We aimed to isolate endophytic fungifrom yellowpassion fruit (Passiflora edulis) leaves, evaluating its biocontrol capacity by in vitroantagonism against phytopathogen Colletotrichum sp. CNPU378. We also carried out greenhouse experiments in bean seedlings. A high colonization frequency was obtained (89%), and the molecular identification based on DNA sequencing attested Colletotrichumas the most frequent genus and minor occurrence of Curvulariaendophytes. The endophytes tested showed different types of competitive interactions in in vitro antagonism inhibition rate ranging from 28.8 to 48.8%. There were 10 promising antagonists tested for their antagonist activity of crude extracts of secondary metabolites, in which strain PE-36 (20.8%) stood out among the other strains evaluated. In the greenhouse assay, plants inoculated only with endophyte Colletotrichumsp. PE-36 was symptomless and suggest that the endophyte strengthened the growth promotion in common bean plants, especially in the root length and number of leaves when compared to control plantsand other treatments. Despite many fungiof Colletotrichumgenus being described as causative agents of anthracnose, in this study, the plant sampled was colonized predominantly by Colletotrichumendophytes living in asymptomatic relationship. By the way,we come across a Colletotrichumsp. endophyte able to antagonize a Colletotrichumsp. pathogen


Sujet(s)
Bioprospection , Phylogenèse , Passiflora/génétique , Passiflora/microbiologie , Colletotrichum , Champignons
13.
Ecotoxicol Environ Saf ; 184: 109642, 2019 Nov 30.
Article de Anglais | MEDLINE | ID: mdl-31539808

RÉSUMÉ

The relevance of Bacillus thuringiensis in pest control strategies have been increasing in recent decades. This entomopathogenic microorganism is considered safe, and its action is highly selective to target organisms. Its toxic effect is attributed to the toxins synthesized during sporulation. The nature of the produced toxins depends on the bacterial variety. Some varieties of B. thuringiensis can synthesize from one to eight distinct toxins, which have specific effects on different orders of susceptible insects. The sugarcane borer, Diatraea saccharalis, is a holometabolous lepidopteran that causes severe damage to sugar cane cultures during its larval phase. Therefore, to evaluate B. thuringiensis serovar Aizawai GC-91 efficiency and its effects on the midgut of first instar D. saccharalis larvae, we reared the insects with contaminated artificial diet for 144 h. Larvae mortality during this period revealed that 5, 10, and 20 g/L concentrations were the most efficient, resulting in 100% mortality of treated larvae, with LC50 and LC90 estimated at 0.307 and 1.330 g/L, respectively. Furthermore, histological and ultrastructural analyses revealed damage to midgut cells. Within the first 24 h of treatment, the midgut of infected insects presented peritrophic membrane degeneration, cytoplasmic vacuolization, and cellular hypertrophy; spherites and calcium granules were also observed. At 48 h of treatment, the digestive system had collapsed, with microvilli degeneration, basement membrane and muscular fiber bundles disruption, and cellular lysis. These results confirm the toxicity of the B. thuringiensis serovar Aizawai GC-91 on D. saccharalis larvae and its potential use as a biocontroller against this pest species.


Sujet(s)
Bacillus thuringiensis , Agents de lutte biologique/pharmacologie , Système digestif/effets des médicaments et des substances chimiques , Papillons de nuit/effets des médicaments et des substances chimiques , Saccharum/microbiologie , Animaux , Protéines bactériennes/pharmacologie , Système digestif/croissance et développement , Endotoxines/pharmacologie , Hémolysines/pharmacologie , Larve/effets des médicaments et des substances chimiques , Larve/croissance et développement , Papillons de nuit/croissance et développement , Lutte biologique contre les nuisibles/méthodes , Saccharum/croissance et développement
14.
Acta biol. colomb ; 24(2): 322-330, May-ago. 2019. tab, graf
Article de Anglais | LILACS-Express | LILACS | ID: biblio-1010860

RÉSUMÉ

ABSTRACT Endophyte microorganisms have great biotechnological interest, with features applicable to different areas and are potentially useful in agriculture. The current study determines the biotechnological potential of endophytic fungi, isolated from leaves of Sapindus saponaria, to control phytopathogenic fungi and evaluate their enzyme production. Molecular taxonomy was performed by sequencing of the ITS1-5.8S-ITS2 ribosomal DNA region, identifying the genera Phomopsis, Sordariomycetes, Diaporthe, and Colletotrichum. In vitro antagonism against phytopathogens showed better results against Fusarium solani and provided inhibition indices between 41.8 % and 67.5 %. The endophytic strain SS81 (Diaporthe citri) presented the highest antagonism index against the pathogen. Against Glomerella sp. and Moniliophthora perniciosa, inhibition rates ranged between 18.7 % and 57.4 % and between 38.3 % and 64.8 %, respectively. Enzyme assays revealed that strain SS65 (Diaporthe sp.) produced 1.16 UI μmol/min of amylase; strain SS77 (Diaporthe sp.) produced 2.74 UI μmol/min of pectinase, and strain SS08 (Diaporthe sp.) produced 1.51 UI μmol/min of cellulase. Thus, the current study shows evidence the importance of isolated endophytes with phytoprotective properties of plants with medicinal properties as alternatives for biological control and natural sources of products with biotechnological interest.


RESUMEN Los microorganismos endofíticos tienen gran interés biotecnológico, con características aplicables a diferentes áreas y potencialmente útiles en la agricultura. El presente estudio determinó el potencial biotecnológico de los hongos endofíticos, aislados de las hojas de Sapindus saponaria, en el control de hongos fitopatógenos y evaluación de su producción de enzimática. La taxonomía molecular fue realizada por la secuencia de la región ITS1-5.8S-ITS2 del ADN ribosomal, identificando los géneros Phomopsis, Sordariomycetes, Diaporthe y Colletotrichum. El antagonismo in vitro contra fitopatógenos mostró mejores resultados contra Fusarium solani y proporcionó índices de inhibición de entre el 41,8 % y el 67,5 %. El linaje endofítico SS81 (Diaporthe citri) presentó el mayor índice de antagonismo contra los patógenos. Contra Glomerella sp. y Moniliophthora perniciosa, las tasas de inhibición variaron entre el 18,7 % y el 57,4 % y entre el 38,3 % y el 64,8 %, respectivamente. El ensayo enzimático reveló que el linaje SS65 (Diaporthe sp.) produjo 1,16 UI μmol / min de amilasa; el linaje SS77 (Diaporthe sp.) produjo 2,74 UI μmol / min de pectinasa; y el linaje SS08 (Diaporthe sp.) produjo 1,51 UI μmol / min de celulasa. Así, el presente estudio evidencia la importancia de los endófitos aislados con propiedades fitoprotectoras como alternativas para el control biológico y como fuentes naturales de productos con interés biotecnológico.

15.
Biosci. j. (Online) ; 35(3): 933-940, may./jun. 2019. tab
Article de Anglais | LILACS | ID: biblio-1048705

RÉSUMÉ

Endoglucanases are enzymes widely employed in different industrial fields, albeit with high production costs. Studies on new microbial sources and low-cost substrates are highly relevant, including those on agro-industrial. Current analysis evaluates peanut hull (PH) and sawdust (SD) as substrates for submerged cultures of 14 endophytic fungi isolated from grapevine (Vitis labrusca L.) cultivars Bordô and Concord. Endophytes were grown on a carboxymethylcellulose (CMC) medium and the cup plate assay showed that eight strains (belonging to genera Cochliobolus, Diaporthe, Fusarium and Phoma) had positive results: enzymatic halos ranged from 10.8±0.02to 15.5±0.07 mm in diameter. Diaporthe sp. strains (GenBank accession codes KM362392, KM362368 and KM362378) and Fusariumculmorum KM362384 were highlighted as the most promising sources. Further, PH and SD as substrates for the fermentation of these fungi were evaluated by the cup plate assay and endoglucanase activity assay. Highest halo diameters were obtained for Diaporthe sp. KM362392: 16.1±0.01 mm (CMC), 14.5±0.01 mm (PH) and 14.7±0.03 mm (SD). The fungus also presented the highest levels of endoglucanase activity: analysis of variance revealed that CMC (3.52±0.98 µmol/min), PH (2.93±0.23 µmol/min) and SD (3.26±0.38 µmol/min) were similarly efficient as substrates. Results deepen knowledge on V. labrusca endophytes that may be endoglucanase sources, eventhough further optimizations in submerged cultures with PH and SD should be undertaken to increase theenzymatic production from these wastes.


Endoglucanases são enzimas amplamente empregadas em diferentes setores industriais; embora sua produção apresente custos elevados. Estudos sobre novas fontes microbianas e substratos mais baratos são de grande importância, incluindo os resíduos agroindustriais. Nesse estudo, casca de amendoim (CA) e serragem (SE) foram testadas como substratos para o cultivo submerso de 14 fungos endofíticos isolados das cultivares Bordô e Concord de videira (Vitis labrusca L.) Os endófitos foram crescidos em meio contendo carboximetilcelulose (CMC) e o ensaio cup plate mostrou resultados positivos para oito fungos (pertencentes aos gêneros Cochliobolus, Diaporthe, Fusarium and Phoma); os halos enzimáticos variaram entre 10,8±0,02 e 15,5±0,07 mm de diâmetro. Linhagens de Diaporthe sp. (códigos de acesso no GenBank KM362392, KM362368 e KM362378) e Fusariumculmorum KM362384 se destacaram como produtores mais promissores. Então, o uso de CA e SE como substratos para a fermentação desses fungos foi avaliado pelo ensaio cup plate e pela quantificação da atividade de endoglucanase. Os maiores halos enzimáticos foram obtidos para Diaporthe sp. KM362392: 16,1±0,01 mm (CMC), 14,5±0,01 mm (CA) e 14,7±0,03 mm (SE). Esse fungo também apresentou os maiores níveis de endoglucanase: a análise de variância revelou que CMC (3,52±0,98 µmol/min), CA (2,93±0,23 µmol/min) e SE (3,26±0,38 µmol/min) foram substratos similarmente eficientes. Esses resultados expandem o conhecimento sobre endófitos de V. labrusca que são fontes de endoglucanases; futuras otimizações quanto ao cultivo submerso com CA e SE podem ser utilizadas para aumentar a produção enzimática a partir do uso desses resíduos.


Sujet(s)
Déchets , Cellulase , Substrats pour Traitement Biologique , Enzymes , Agroindustrie , Endophytes
16.
Indian J Microbiol ; 59(2): 217-224, 2019 Jun.
Article de Anglais | MEDLINE | ID: mdl-31031437

RÉSUMÉ

Fungus-caused diseases are among the greatest losses in grapevine culture. Biological control of pathogens by endophytes may be used to decrease fungicide application rates and environmental impacts. Previously, Diaporthe sp. B46-64 and C27-07 were highlighted as antagonists of grapevine phytopathogens. Herein, molecular multigene (ITS-TUB-TEF1) identification and phylogenetic analysis allowed the identification of these endophytes as belonging to Diaporthe schini species. Agrobacterium tumefaciens-mediated transformation was employed for obtaining 14 stable and traceable gfp- or DsRed-expressing transformants, with high transformation efficiency: 96% for the pFAT-GFP plasmid and 98% for pCAM-DsRed plasmid. Transformants were resistant to hygromycin B with gene hph confirmed by polymerase chain reaction and proved to be mitotically stable, expressing the fluorescent phenotype, with morphological differences in the colonies when compared with wild strains. In vitro antagonism tests revealed an increased antagonistic activity of some transformant strains. The current genetic transformation of D. schini mediated by A. tumefaciens proved to be an efficient technique within the randomized insertion of reporter genes for the monitoring of the strain in the environment.

17.
World J Microbiol Biotechnol ; 34(4): 56, 2018 Mar 29.
Article de Anglais | MEDLINE | ID: mdl-29594576

RÉSUMÉ

Plant leaves (phyllosphere) have a great potential for colonization and microbial growth, consisting of a dynamic environment in which several factors can interfere with the microbial population structure. The use of genetically modified (GM) plants has introduced several traits in agriculture, such as the improvement of plant drought tolerance, as observed in the AtAREB1 transcription factor overexpression in soybean (Glycine max L. Merrill). The present study aimed at investigating the taxonomic and functional profile of the leaf microbial community of bacteria found in GM (drought-tolerant event 1Ea2939) and conventional (BR 16) soybean plants. Bacterial DNA was extracted from leaf samples collected from each genotype and used for microbial diversity and richness analysis through the MiSeq Illumina platform. Functional prediction was performed using the PICRUSt tool and the STAMP v 2.1.3 software. The obtainment of the GM event 1Ea2939 showed minimum effects on the microbial community and in the potential for chemical-genetic communication, i.e. in the potential for symbiotic and/or mutualistic interaction between plants and their natural microbiota.


Sujet(s)
Protéines d'Arabidopsis/génétique , Bactéries/classification , Facteurs de transcription à motif basique et à glissière à leucines/génétique , Endophytes/classification , Glycine max/génétique , Glycine max/microbiologie , Microbiote , Feuilles de plante/microbiologie , Végétaux génétiquement modifiés/génétique , Arabidopsis/génétique , Bactéries/génétique , Bactéries/isolement et purification , Biodiversité , ADN bactérien/génétique , Sécheresses , Endophytes/génétique , Endophytes/isolement et purification , Fabaceae/génétique , Fabaceae/microbiologie , Microbiote/génétique , Phylogenèse , ARN ribosomique 16S/génétique , Microbiologie du sol
18.
Curr Microbiol ; 75(5): 588-596, 2018 May.
Article de Anglais | MEDLINE | ID: mdl-29299623

RÉSUMÉ

Endophytes are fungi and bacteria that inhabit plant tissues without causing disease. Endophytes have characteristics that are important for the health of the plant and have been isolated from several plants of economic and medicinal interest but rarely from ornamental plants. The current study isolates and identifies endophytic fungi from the leaves of Pachystachys lutea and evaluates the antagonistic activity of these endophytes as well as cellulase production by the endophytes. Fungi were isolated by fragmentation from surface-disinfected leaves and were identified by the sequencing of the ITS gene and the genes coding for EF 1-α and ß-tubulin followed by multilocus sequence analysis. Molecular taxonomic analysis revealed that 78% of the identified fungi belonged to the genus Diaporthe. We also identified strains belonging to the genera Colletotrichum, Phyllosticta, Xylaria, Nemania, and Alternaria. Most of the strains tested were able to inhibit the growth of pathogenic fungi, especially PL09 (Diaporthe sp.), which inhibited the growth of Colletotrichum sp., and PL03 (Diaporthe sp.), which inhibited the growth of Fusarium oxysporum. The production of cellulase ranged from 0.87 to 1.60 µmol/min. Foliar endophytic fungal isolates from P. lutea showed promising results for the in vitro control of plant pathogens and for cellulase production. This paper is the first report on culturable endophytic fungi isolated from the ornamental plant P. lutea.


Sujet(s)
Endophytes/isolement et purification , Endophytes/physiologie , Champignons/isolement et purification , Champignons/physiologie , Magnoliopsida/microbiologie , Maladies des plantes/prévention et contrôle , Antibiose , Colletotrichum/physiologie , Endophytes/classification , Endophytes/génétique , Champignons/classification , Champignons/génétique , Fusarium/physiologie , Magnoliopsida/croissance et développement , Phylogenèse , Maladies des plantes/microbiologie , Feuilles de plante/microbiologie
19.
Nat Prod Res ; 32(23): 2783-2790, 2018 Dec.
Article de Anglais | MEDLINE | ID: mdl-28948837

RÉSUMÉ

In the present study, biological activity and chemical composition of two crude extracts of endophytic fungal strains of Bipolaris genera isolated from two species of aquatic macrophytes: Eichhornia azurea (Kunth) and Eichhornia crassipes (Mart.) were investigated. The nuclear magnetic resonance and mass spectrometry data provided the identification of three main compounds: curvulin (1), spirostaphylotrichin R (2) and U (3). The fragmentation mechanism of the precursor ions towards collision induced dissociation (CID) tandem mass spectrometry experiment (MS/MS) is also proposed. Furthermore, biological screening of the crude extracts displayed antileishmanial activity with IC50 values ranging from 70-84.2 µg.mL-1.


Sujet(s)
Eichhornia/composition chimique , Ascomycota , Eichhornia/microbiologie , Endophytes , Concentration inhibitrice 50 , Leishmania/effets des médicaments et des substances chimiques , Spectroscopie par résonance magnétique , Deuteromycota , Extraits de plantes/composition chimique , Extraits de plantes/toxicité , Spectrométrie de masse en tandem
20.
Environ Monit Assess ; 189(2): 88, 2017 Feb.
Article de Anglais | MEDLINE | ID: mdl-28144871

RÉSUMÉ

The current study investigates the potential for discolouration and degradation of Reactive Blue 19 and Reactive Black 5 textile dyes by endophytic fungi Phlebia sp. and Paecilomyces formosus as well as the potential cytotoxicity of products or by-products generated by the treatments in fish erythrocytes. It was observed at 30 days that both endophytes showed biodegradation activity with 0.1 g mL-1 of dyes. P. formosus showed highest extracellular and intracellular protein content levels after the 15th day, and Phlebia sp. stands out for production of extracellular laccase, indicating that this enzyme may be associated with the decolouration capacity. The dyes showed toxic effects in fishes at 0.01 g mL-1 concentration, resulting in the appearance of micronuclei in erythrocyte cells. When degraded dyes treated by endophytes were tested, the frequency of micronuclei reduced approximately 20%, indicating the effectiveness of these endophytic in the treatment of textile dyes with less environmental impact, thus indicating a potential for application of these fungi in bioremediation process.


Sujet(s)
Basidiomycota/métabolisme , Dépollution biologique de l'environnement , Agents colorants/métabolisme , Surveillance de l'environnement , Paecilomyces/métabolisme , Animaux , Anthraquinones/effets indésirables , Anthraquinones/métabolisme , Agents colorants/effets indésirables , Endophytes/métabolisme , Érythrocytes/effets des médicaments et des substances chimiques , Poissons , Protéines fongiques/métabolisme , Laccase/métabolisme , Tests de micronucleus/médecine vétérinaire , Naphtalènesulfonates/effets indésirables , Naphtalènesulfonates/métabolisme , Industrie textile , Élimination des déchets liquides
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