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Fabio Ribeiro Braga - One of the best experts on this subject based on the ideXlab platform.
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Extracellular biosynthesis of silver nanoparticles using the cell-free filtrate of Nematophagous Fungus Duddingtonia flagrans
International journal of nanomedicine, 2017Co-Authors: Laryssa Pinheiro Costa Silva, Jackson Victor De Araujo, Anderson Rocha Aguiar, Carolina Magri Ferraz, Jairo Pinto De Oliveira, Wanderson Juvencio Keijok, A. R. Silva, Marco Cesar Cunegundes Guimarães, Fernando Luiz Tobias, Fabio Ribeiro BragaAbstract:The biosynthesis of metallic nanoparticles (NPs) using biological systems such as fungi has evolved to become an important area of nanobiotechnology. Herein, we report for the first time the extracellular synthesis of highly stable silver NPs (AgNPs) using the Nematophagous Fungus Duddingtonia flagrans (AC001). The fungal cell-free filtrate was analyzed by the Bradford method and 3,5-dinitrosalicylic acid assay and used to synthesize the AgNPs in the presence of a 1 mM AgNO3 solution. They have been characterized by UV-Vis spectroscopy, X-ray diffraction, transmission electron microscopy, dynamic light scattering, Zeta potential measurements, Fourier-transform infrared, and Raman spectroscopes. UV-Vis spectroscopy confirmed bioreduction, while X-ray diffractometry established the crystalline nature of the AgNPs. Dynamic light scattering and transmission electron microscopy images showed approximately 11, 38 nm monodisperse and quasispherical AgNPs. Zeta potential analysis was able to show a considerable stability of AgNPs. The N-H stretches in Fourier-transform infrared spectroscopy indicate the presence of protein molecules. The Raman bands suggest that chitinase was involved in the growth and stabilization of AgNPs, through the coating of the particles. Our results show that the NPs we synthesized have good stability, high yield, and monodispersion.
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Interaction and activity of Nematophagous Fungus Duddingtonia flagrans on Haematobia irritans (Diptera: Muscidae)
African Journal of Microbiology Research, 2017Co-Authors: Anderson Rocha Aguiar, Jackson Victor De Araujo, Filippe Elias De Freitas Soares, Leticia Prates Martins, Gabriella Lima Santos, Aline Lisboa Bernardo Canal, Emy Hiura, Carolina Magri Ferraz, Fabio Ribeiro BragaAbstract:Haematobia irritans, also known as the horn fly, is a “plague” that spreads rapidly among cattle herds, especially in the southeast of Brazil. The aim of this study was to evaluate the interaction and activity of Nematophagous Fungus Duddingtonia flagrans (AC001) on H. irritans (Diptera: Muscidae). The experiment was conducted using the Nematophagous Fungus (AC001), which is harmless to animals, humans, and the environment. At the beginning of the experimental trial, samples of adult H. irritans were collected manually, directly from the dorsal region of naturally infested cattle of the Nelore breed. The flies where divided into two groups: groups of adult flies treated with AC001 (treated group) and groups of flies that did not receive treatment (control group). During the trial, the experiment was monitored daily for five days and the results were recorded. The results showed that the AC001 fungal isolate grew, colonized, and consequently caused the death of the flies in the treated group, while in the control group, no interaction or growth was observed, and the flies remained alive. It was concluded that the Fungus D. flagrans interacted with adult flies, taking into consideration a “possible attack” by chitinase enzymes, since the fungal isolate drew on the chitin contained in the exoskeletons of the insects. In addition, attention should be focused on new studies that can demonstrate that, in the future, biological control of the horn fly could be an effective and safe method when compared with other methods. Key words: Biological control, Duddingtonia flagrans, horn fly, Nelore, Brazil.
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Nematocidal activity of extracellular enzymes produced by the Nematophagous Fungus Duddingtonia flagrans on cyathostomin infective larvae.
Veterinary parasitology, 2015Co-Authors: Fabio Ribeiro Braga, Filippe Elias Freitas Soares, Thais Zanotti Giuberti, Aline Del Carmen Garcias Lopes, Tracy Lacerda, Tiago De Hollanda Ayupe, Paula Viana Queiroz, Angélica De Souza Gouveia, Larissa Pinheiro, Andreia Luíza AraújoAbstract:Duddingtonia flagrans produces chitinases, however, optimization of the production of these enzymes still needs to be explored, and its nematocidal activity should still be the subject of studies. The objective of the present study was to optimize chitinase production, and evaluate the nematocidal activity of extracellular enzymes produced by the Nematophagous Fungus D. flagrans on cyathostomin infective larvae. An isolate from D. flagrans (AC001) was used in this study. For the production of enzymes (protease and chitinase), two different culture media were inoculated with AC001 conidia. Both enzymes were purified. The statistical Plackett-Burman factorial design was used to investigate some variables and their effect on the production of chitinases by D. flagrans. After that, the design central composite (CCD) was used in order to determine the optimum levels and investigate the interactions of these variables previously observed. Only two variables (moisture and incubation time), in the evaluated levels, had a significant effect (p
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Nematocidal activity of extracellular enzymes produced by the Nematophagous Fungus Duddingtonia flagrans on cyathostomin infective larvae.
Veterinary Parasitology, 2015Co-Authors: Fabio Ribeiro Braga, Filippe Elias De Freitas Soares, Angélica De Souza Gouveia, Thais Zanotti Giuberti, Tracy Lacerda, Paula Viana Queiroz, Larissa Pinheiro, Aline Del Carmen Garcias Lopes, Tiago De Hollanda Ayupe, Andreia Luíza AraújoAbstract:Abstract Duddingtonia flagrans produces chitinases, however, optimization of the production of these enzymes still needs to be explored, and its nematocidal activity should still be the subject of studies. The objective of the present study was to optimize chitinase production, and evaluate the nematocidal activity of extracellular enzymes produced by the Nematophagous Fungus D. flagrans on cyathostomin infective larvae. An isolate from D. flagrans (AC001) was used in this study. For the production of enzymes (protease and chitinase), two different culture media were inoculated with AC001 conidia. Both enzymes were purified. The statistical Plackett–Burman factorial design was used to investigate some variables and their effect on the production of chitinases by D. flagrans . After that, the design central composite (CCD) was used in order to determine the optimum levels and investigate the interactions of these variables previously observed. Only two variables (moisture and incubation time), in the evaluated levels, had a significant effect ( p D. flagrans , individually or together (after 24 h), led to a significant reduction ( p 3 , when compared to the control, with following reduction percentage values: 19.4% (protease), 15.5% (chitinase), and 20.5% (protease + chitinase). Significant differences were observed ( p
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Proteolytic activity of the Nematophagous Fungus Arthrobotrys sinensis on Angiostrongylus vasorum larvae
BMC research notes, 2014Co-Authors: Filippe Elias De Freitas Soares, Fabio Ribeiro Braga, José Humberto De Queiroz, Walter Dos Santos Lima, Tatiana Tonini Zamprogno, Jackson Victor De AraujoAbstract:The predatory Nematophagous Fungus Arthrobotrys sinensis (SF53) produces three proteases with nematicidal activity when grown on solid media culture. However, the proteolytic profile produced by this Fungus, when grown in liquid culture medium remains unknown. Thus, the objective of this work was to evaluate the production of proteases from Nematophagous Fungus Arthrobotrys sinensis in liquid medium and its nematicidal activity on first stage larvae of A. vasorum. Proteases were obtained in its crude form, using Whatman no.1 filter paper, followed by centrifugation for 5 min at 10 × g and 4°C. A zymogram was performed with co-polymerized casein in an acrylamide gel as substrate. An in vitro assay to evaluate the nematicidal action of the proteases of A. sinensis (SF53) produced in liquid medium on A. vasorum L1 was conducted. By the analysis of the zymogram, it was observed a single halo at the beginning of digestion of the gel, suggesting that the three proteases of SF53 are produced in an enzymatic complex of large molecular weight. Regarding nematicidal activity, within 24 hours, the proteases produced in liquid medium of A. sinensis (SF53) showed a percentage reduction of 64% on the number of L1 of A. vasorum. In the present work, it is suggested that the three proteases of SF53 are produced in an enzymatic complex and was also demonstrated that these enzymes were effective in destroying A. vasorum L1.
Jackson Victor De Araujo - One of the best experts on this subject based on the ideXlab platform.
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Extracellular biosynthesis of silver nanoparticles using the cell-free filtrate of Nematophagous Fungus Duddingtonia flagrans
International journal of nanomedicine, 2017Co-Authors: Laryssa Pinheiro Costa Silva, Jackson Victor De Araujo, Anderson Rocha Aguiar, Carolina Magri Ferraz, Jairo Pinto De Oliveira, Wanderson Juvencio Keijok, A. R. Silva, Marco Cesar Cunegundes Guimarães, Fernando Luiz Tobias, Fabio Ribeiro BragaAbstract:The biosynthesis of metallic nanoparticles (NPs) using biological systems such as fungi has evolved to become an important area of nanobiotechnology. Herein, we report for the first time the extracellular synthesis of highly stable silver NPs (AgNPs) using the Nematophagous Fungus Duddingtonia flagrans (AC001). The fungal cell-free filtrate was analyzed by the Bradford method and 3,5-dinitrosalicylic acid assay and used to synthesize the AgNPs in the presence of a 1 mM AgNO3 solution. They have been characterized by UV-Vis spectroscopy, X-ray diffraction, transmission electron microscopy, dynamic light scattering, Zeta potential measurements, Fourier-transform infrared, and Raman spectroscopes. UV-Vis spectroscopy confirmed bioreduction, while X-ray diffractometry established the crystalline nature of the AgNPs. Dynamic light scattering and transmission electron microscopy images showed approximately 11, 38 nm monodisperse and quasispherical AgNPs. Zeta potential analysis was able to show a considerable stability of AgNPs. The N-H stretches in Fourier-transform infrared spectroscopy indicate the presence of protein molecules. The Raman bands suggest that chitinase was involved in the growth and stabilization of AgNPs, through the coating of the particles. Our results show that the NPs we synthesized have good stability, high yield, and monodispersion.
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Interaction and activity of Nematophagous Fungus Duddingtonia flagrans on Haematobia irritans (Diptera: Muscidae)
African Journal of Microbiology Research, 2017Co-Authors: Anderson Rocha Aguiar, Jackson Victor De Araujo, Filippe Elias De Freitas Soares, Leticia Prates Martins, Gabriella Lima Santos, Aline Lisboa Bernardo Canal, Emy Hiura, Carolina Magri Ferraz, Fabio Ribeiro BragaAbstract:Haematobia irritans, also known as the horn fly, is a “plague” that spreads rapidly among cattle herds, especially in the southeast of Brazil. The aim of this study was to evaluate the interaction and activity of Nematophagous Fungus Duddingtonia flagrans (AC001) on H. irritans (Diptera: Muscidae). The experiment was conducted using the Nematophagous Fungus (AC001), which is harmless to animals, humans, and the environment. At the beginning of the experimental trial, samples of adult H. irritans were collected manually, directly from the dorsal region of naturally infested cattle of the Nelore breed. The flies where divided into two groups: groups of adult flies treated with AC001 (treated group) and groups of flies that did not receive treatment (control group). During the trial, the experiment was monitored daily for five days and the results were recorded. The results showed that the AC001 fungal isolate grew, colonized, and consequently caused the death of the flies in the treated group, while in the control group, no interaction or growth was observed, and the flies remained alive. It was concluded that the Fungus D. flagrans interacted with adult flies, taking into consideration a “possible attack” by chitinase enzymes, since the fungal isolate drew on the chitin contained in the exoskeletons of the insects. In addition, attention should be focused on new studies that can demonstrate that, in the future, biological control of the horn fly could be an effective and safe method when compared with other methods. Key words: Biological control, Duddingtonia flagrans, horn fly, Nelore, Brazil.
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Proteolytic activity of the Nematophagous Fungus Arthrobotrys sinensis on Angiostrongylus vasorum larvae
BMC research notes, 2014Co-Authors: Filippe Elias De Freitas Soares, Fabio Ribeiro Braga, José Humberto De Queiroz, Walter Dos Santos Lima, Tatiana Tonini Zamprogno, Jackson Victor De AraujoAbstract:The predatory Nematophagous Fungus Arthrobotrys sinensis (SF53) produces three proteases with nematicidal activity when grown on solid media culture. However, the proteolytic profile produced by this Fungus, when grown in liquid culture medium remains unknown. Thus, the objective of this work was to evaluate the production of proteases from Nematophagous Fungus Arthrobotrys sinensis in liquid medium and its nematicidal activity on first stage larvae of A. vasorum. Proteases were obtained in its crude form, using Whatman no.1 filter paper, followed by centrifugation for 5 min at 10 × g and 4°C. A zymogram was performed with co-polymerized casein in an acrylamide gel as substrate. An in vitro assay to evaluate the nematicidal action of the proteases of A. sinensis (SF53) produced in liquid medium on A. vasorum L1 was conducted. By the analysis of the zymogram, it was observed a single halo at the beginning of digestion of the gel, suggesting that the three proteases of SF53 are produced in an enzymatic complex of large molecular weight. Regarding nematicidal activity, within 24 hours, the proteases produced in liquid medium of A. sinensis (SF53) showed a percentage reduction of 64% on the number of L1 of A. vasorum. In the present work, it is suggested that the three proteases of SF53 are produced in an enzymatic complex and was also demonstrated that these enzymes were effective in destroying A. vasorum L1.
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An isolate of the Nematophagous Fungus Monacrosporium thaumasium for the control of cattle trichostrongyles in south-eastern Brazil.
Journal of helminthology, 2014Co-Authors: R.c.l. Assis, Jackson Victor De Araujo, Fabio Ribeiro Braga, F.d. Luns, R.l. Assis, J.l. Marcelino, P.c. Freitas, M.a.s. AndradeAbstract:A mycelial formulation in sodium alginate pellets of the Nematophagous Fungus Monacrosporium thaumasium (isolate NF34A) was assessed in the biological control of beef cattle trichostrongyles in tropical Brazil. Two groups of ten male Nellore calves aged 6 months, a Fungus-treated group and a control group, were fed on a pasture of Brachiaria decumbens naturally infected with larvae of cattle trichostrongyles. The Fungus-treated group received doses of sodium alginate mycelial pellets orally (1 g pellets (0.2 g Fungus)/10 kg live weight) twice a week for 12 months. At the end of the study there was a significant reduction (P< 0.01) in the number of eggs per gram of faeces and coprocultures of the Fungus-treated group--47.8% and 50.2%, respectively--in relation to the control group. There was a 47.3% reduction in herbage samples, collected up to 0-20 cm from faecal pats, between the Fungus-treated and control groups, and a 58% reduction when the sampling distance was 20-40 cm from faecal pats (P< 0.01). The treatment with sodium alginate pellets containing the nematode-trapping Fungus M. thaumasium reduced trichostrongyles in tropical south-eastern Brazil and could be an effective tool for the biological control of this parasitic nematode in beef cattle. However, in such a tropical climate with low rainfall the fungal viability can be reduced.
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The Nematophagous Fungus Monacrosporium thaumasium and its nematicidal activity on Angiostrongylus vasorum.
Revista iberoamericana de micologia, 2013Co-Authors: Filippe Elias De Freitas Soares, Jackson Victor De Araujo, Fabio Ribeiro Braga, Walter Dos Santos Lima, José Humberto De QueirozAbstract:Abstract Background The dog acts as a reservoir and environmental disseminator of potentially zoonotic parasites. Aims The objective of this work was to study the Fungus Monacrosporium thaumasium regarding its nematicidal potential in laboratory trials and its proteolytic profile. Methods The in vitro test was carried out through two assays (A and B). In assay A, conidia of the Fungus N34a were added in positive coprocultures for Angiostrongylus vasorum . In assay B, crude extract (treated group) and distilled water (control group) were added to coprocultures. Next, the proteolytic profile of crude extract of the Nematophagous Fungus M. thaumasium (NF34a) was revealed by performing a zymogram. Results There was a reduction ( p M. thaumasium produces a protease of approximately 40 kDa. Conclusions The results of this work confirm that the conidia as well as the crude extract of the Fungus M. thaumasium may be used to control A. vasorum L 1 . The proteolytic profile suggested the presence of one protease (Mt1) of approximately 40 kDa that in the future may be used in biological control of L 1 of this nematode.
Ke-qin Zhang - One of the best experts on this subject based on the ideXlab platform.
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Functional Characterization of Core Regulatory Genes Involved in Sporulation of the Nematophagous Fungus Purpureocillium lavendulum
mSphere, 2020Co-Authors: He-yu Yang, Yan-ru Cao, Quan-quan Hui, Hai-feng Fan, Chen-chen Zhang, Jing-jing Han, Zhi-yi Guo, Ke-qin ZhangAbstract:ABSTRACT The Nematophagous Fungus Purpureocillium lavendulum is a natural enemy of plant-parasitic nematodes, which cause severe economic losses in agriculture worldwide. The production of asexual spores (conidia) in P. lavendulum is crucial for its biocontrol activity against nematodes. In this study, we characterized the core regulatory genes involved in conidiation of P. lavendulum at the molecular level. The central regulatory pathway is composed of three genes, P. lavendulumbrlA (PlbrlA), PlabaA, and PlwetA, which regulate the early, middle, and late stages of asexual development, respectively. The deletion of PlbrlA completely inhibited conidiation, with only conidiophore stalks produced. PlAbaA determines the differentiation of conidia from phialides. The deletion of PlwetA affected many phenotypes related to conidial maturation, including abscission of conidia from conidium strings, thickening of the cell wall layers, vacuole generation inside the cytoplasm, production of trehalose, tolerance to heat shock, etc. Comparative analyses showed that the upstream regulators of the core regulatory pathway of conidiation, especially the “fluffy” genes, were different from those in Aspergillus. Besides their roles in conidiation, the central regulators also influence the production of secondary metabolites, such as the leucinostatins, in P. lavendulum. Our study revealed a set of essential genes controlling conidiation in P. lavendulum and provided a framework for further molecular genetic studies on Fungus-nematode interactions and for the biocontrol of plant-parasitic nematodes. IMPORTANCE Plant-parasitic nematodes cause serious damage to crops throughout the world. Purpureocillium lavendulum is a Nematophagous Fungus which is a natural enemy of nematodes and a potential biocontrol agent against plant-parasitic nematodes. The conidia play an important role during infection of nematodes. In this study, we identified and characterized genes involved in regulating asexual development of P. lavendulum. We found that these genes not only regulate conidiation but also influence secondary-metabolite production. This work provides a basis for future studies of Fungus-nematode interactions and nematode biocontrol.
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The pH sensing receptor AopalH plays important roles in the Nematophagous Fungus Arthrobotrys oligospora
Fungal biology, 2019Co-Authors: Meng Wang, James Borneman, Jinkui Yang, Ke-qin ZhangAbstract:There is well-conserved PacC/Rim101 signaling among ascomycete fungi to mediate environmental pH sensing. For pathogenic fungi, this pathway not only enables fungi to grow over a wide pH range, but it also determines whether these fungi can successfully colonize and invade the targeted host. Within the pal/PacC pathway, palH is a putative ambient pH sensor with a seven-transmembrane domain. To characterize the function of a palH homolog, AopalH, in the Nematophagous Fungus Arthrobotrys oligospora, we knocked out the encoding gene of AopalH through homologous recombination, and the transformants exhibited slower growth rates, greater sensitivities to cationic and hyperoxidation stresses, as well as reduced conidiation and reduced trap formation, suggesting that the pH regulatory system has critical functions in Nematophagous fungi. Our results provide novel insights into the mechanisms of pH response and regulation in fungi.
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Multiple gene genealogical analyses of a Nematophagous Fungus Paecilomyces lilacinus from China.
Journal of microbiology (Seoul Korea), 2013Co-Authors: Ke-qin ZhangAbstract:Paecilomyces lilacinus is a geographically widespread Nematophagous Fungus and a promising biological control agent against plant parasitic nematodes. However, relatively little is known about its patterns of genetic variation through its broad geographic and ecological contexts. In this study, we analyzed the genetic variation of 2 virulence-associated genes (PLS and PLC) and 4 housekeeping gene fragments (ITS, RPB1, RPB2, and β-tubulin) among 80 P. lilacinus specimens collected from 7 locations in China. Various degrees of polymorphism and haplotype diversity were observed among the six gene fragments. However, no genetic differentiation was observed among the geographic populations, consistent with extensive gene flow among these geographic populations of P. lilacinus in China. Our analysis also suggested that clonal reproduction was the predominant mode of reproduction in natural populations of P. lilacinus.
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Regulation of subtilisin-like protease prC expression by nematode cuticle in the Nematophagous Fungus Clonostachys rosea
Environmental microbiology, 2010Co-Authors: Chenggang Zou, Xian-yong Liu, Nan Tao, Jinkui Yang, Wen-jing Liu, Xiaowei Huang, Zhongwei Gan, Ke-qin ZhangAbstract:Summary Nematophagous fungi have been used as biological control agents against nematodes parasitic to plants and animals. These fungi can secret subtilisin-like extracellular serine proteases during the infection of nematodes. The expression of these subtilisin-like serine proteases is regulated by nitrogen sources, including nematode cuticle. However, the mechanisms underlying the nitrogen sources-induced expression of these serine proteases is not well understood. In this study, we investigated the effect of nitrogen sources on the expression of a subtilisin-like extracellular protease, prC, in the Nematophagous Fungus Clonostachys rosea. Disruption of prC attenuated infection of the Fungus to nematodes, indicating that this gene functions as a virulence factor. The inhibition of basal expression of prC by the preferred nitrogen sources (glutamine, ammonia) occurred at the transcriptional level. In contrast, nematode cuticle induced the expression of prC at the post-transcriptional level. The inducible expression of prC by nematode cuticle was significantly suppressed by glutamine, ammonia and phenylmethylsulfonyl fluoride (an inhibitor of serine protease). Thus, the existence of active PrC, albeit at a low level in the medium, is probably essential for further induction of this gene by nematode cuticle. Moreover, the low molecule weight (
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regulation of subtilisin like protease prc expression by nematode cuticle in the Nematophagous Fungus clonostachys rosea
Environmental Microbiology, 2010Co-Authors: Chenggang Zou, Xian-yong Liu, Nan Tao, Jinkui Yang, Wen-jing Liu, Xiaowei Huang, Zhongwei Gan, Ke-qin ZhangAbstract:Summary Nematophagous fungi have been used as biological control agents against nematodes parasitic to plants and animals. These fungi can secret subtilisin-like extracellular serine proteases during the infection of nematodes. The expression of these subtilisin-like serine proteases is regulated by nitrogen sources, including nematode cuticle. However, the mechanisms underlying the nitrogen sources-induced expression of these serine proteases is not well understood. In this study, we investigated the effect of nitrogen sources on the expression of a subtilisin-like extracellular protease, prC, in the Nematophagous Fungus Clonostachys rosea. Disruption of prC attenuated infection of the Fungus to nematodes, indicating that this gene functions as a virulence factor. The inhibition of basal expression of prC by the preferred nitrogen sources (glutamine, ammonia) occurred at the transcriptional level. In contrast, nematode cuticle induced the expression of prC at the post-transcriptional level. The inducible expression of prC by nematode cuticle was significantly suppressed by glutamine, ammonia and phenylmethylsulfonyl fluoride (an inhibitor of serine protease). Thus, the existence of active PrC, albeit at a low level in the medium, is probably essential for further induction of this gene by nematode cuticle. Moreover, the low molecule weight (< 3 kD) degradation products of nematode cuticle could significantly induce the expression of prC. Ammonia suppresses the virulence of C. rosea against nematodes, probably by inhibiting prC expression. Thus, the Nematophagous fungi probably could not function well as biocontrol agents in fields fertilized with a large amount of ammonium salt.
G.r. Carvalho - One of the best experts on this subject based on the ideXlab platform.
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Biological control of cyathostomin (Nematoda: Cyathostominae) with Nematophagous Fungus Monacrosporium thaumasium in tropical southeastern Brazil
Veterinary Parasitology, 2010Co-Authors: Alexandre De Oliveira Tavela, Sebastiao Rodrigo Ferreira, Jackson Victor De Araujo, Rogerio Oliva Carvalho, Andre R Silva, Fabio Ribeiro Braga, Juliana Milani Araujo, G.r. CarvalhoAbstract:Horses are hosts to a wide variety of helminthes; the most important are the cyathostomin, or small strongyles. The viability of a fungal formulation (pellets) using the nematode-trapping Fungus Monacrosporium thaumasium was assessed in biological control of horse cyathostomin. Two groups (Fungus-treated and control) consisted of six mares in each group, crossbred (ages of 2.5 and 3.5 years), were placed in pastures of Cynodon sp. naturally infected with horse cyathostomin larvae. In the treated group, each animal received 1 g/10 kg body weight (0.2 g/10 kg live weight of Fungus) of pellets of sodium alginate matrix containing the Fungus M. thaumasium orally, twice a week for 6 months. In the control group, animals received (1 g/10 kg body weight) of pellets without Fungus. The egg count per gram of feces showed difference (p 0.05) between the average weight gains in both animal groups. The treatment of horses with pellets containing the Nematophagous Fungus M. thaumasium can be effective in controlling cyathostomin in the tropical region of southeastern Brazil.
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Viability of the Nematophagous Fungus Pochonia chlamydosporia after passage through the gastrointestinal tract of horses.
Veterinary Parasitology, 2009Co-Authors: Fabio Ribeiro Braga, Sebastiao Rodrigo Ferreira, Jackson Victor De Araujo, Rogerio Oliva Carvalho, Andre R Silva, Juliana Milani Araujo, G.r. CarvalhoAbstract:Abstract The predatory capacity of the Nematophagous Fungus Pochonia chlamydosporia (isolate VC4) embedded in sodium alginate pellets after passage through the gastrointestinal tract of horses was assessed in vitro against Oxyuris equi eggs. Twelve previously dewormed crossbred mares, average weight of 362.5 kg (±21) were used in the experiment. Each animal of the treated group received an oral dose (100 g) of sodium alginate pellets containing P. chlamydosporia mycelial mass. The control group received pellets without Fungus. Faecal samples from Fungus-treated and control groups were collected at intervals of 8, 12, 24, 36, 48 and 72 h after pellet administration and placed in Petri dishes containing 2% water-agar. One thousand eggs of O. equi were plated in Petri dishes of both treated and control groups, with six replicates, and incubated in oven, 25 °C, in the dark, for 30 days. At the end of the experiment, one hundred eggs were removed from each Petri dish and classified according to the following parameters: type 1, physiological and biochemical effect without morphological damage to eggshell, with hyphae adhered to the shell; type 2, lytic effect with morphological change in the eggshell and embryo without hyphal penetration, and type 3, lytic effect with morphological change in the eggshell and embryo, with hyphal penetration and internal egg colonization. Chlamydospore production was observed in Petri dishes of the treated group. The isolate VC4 remained viable after passing through the gastrointestinal tract of horses and maintained the ovicidal activity against O. equi eggs when compared with the control group ( p P. chlamydosporia could be used as an effective biological control agent of O. equi eggs in natural conditions.
Luis Vicente Lopez-llorca - One of the best experts on this subject based on the ideXlab platform.
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Expression and specificity of a chitin deacetylase from the Nematophagous Fungus Pochonia chlamydosporia potentially involved in pathogenicity.
Scientific reports, 2018Co-Authors: Almudena Aranda-martinez, Laia Grifoll-romero, Hugo Aragunde, Enea Sancho-vaello, Xevi Biarnés, Luis Vicente Lopez-llorca, Antoni PlanasAbstract:Chitin deacetylases (CDAs) act on chitin polymers and low molecular weight oligomers producing chitosans and chitosan oligosaccharides. Structurally-defined, partially deacetylated chitooligosaccharides produced by enzymatic methods are of current interest as bioactive molecules for a variety of applications. Among Pochonia chlamydosporia (Pc) annotated CDAs, gene pc_2566 was predicted to encode for an extracellular CE4 deacetylase with two CBM18 chitin binding modules. Chitosan formation during nematode egg infection by this Nematophagous Fungus suggests a role for their CDAs in pathogenicity. The P. chlamydosporia CDA catalytic domain (PcCDA) was expressed in E. coli BL21, recovered from inclusion bodies, and purified by affinity chromatography. It displays deacetylase activity on chitooligosaccharides with a degree of polymerization (DP) larger than 3, generating mono- and di-deacetylated products with a pattern different from those of closely related fungal CDAs. This is the first report of a CDA from a Nematophagous Fungus. On a DP5 substrate, PcCDA gave a single mono-deacetylated product in the penultimate position from the non-reducing end (ADAAA) which was then transformed into a di-deacetylated product (ADDAA). This novel deacetylation pattern expands our toolbox of specific CDAs for biotechnological applications, and will provide further insights into the determinants of substrate specificity in this family of enzymes.
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Chitosan enhances parasitism of Meloidogyne javanica eggs by the Nematophagous Fungus Pochonia chlamydosporia
Fungal biology, 2016Co-Authors: Nuria Escudero, Sebastiao Rodrigo Ferreira, Federico Lopez-moya, Miguel A. Naranjo-ortiz, Ana I. Marin-ortiz, Christopher R. Thornton, Luis Vicente Lopez-llorcaAbstract:Pochonia chlamydosporia (Pc), a Nematophagous Fungus and root endophyte, uses appressoria and extracellular enzymes, principally proteases, to infect the eggs of plant parasitic nematodes (PPN). Unlike other fungi, Pc is resistant to chitosan, a deacetylated form of chitin, used in agriculture as a biopesticide to control plant pathogens. In the present work, we show that chitosan increases Meloidogyne javanica egg parasitism by P. chlamydosporia. Using antibodies specific to the Pc enzymes VCP1 (a subtilisin), and SCP1 (a serine carboxypeptidase), we demonstrate chitosan elicitation of the fungal proteases during the parasitic process. Chitosan increases VCP1 immuno-labelling in the cell wall of Pc conidia, hyphal tips of germinating spores, and in appressoria on infected M. javanica eggs. These results support the role of proteases in egg parasitism by the Fungus and their activation by chitosan. Phylogenetic analysis of the Pc genome reveals a large diversity of subtilisins (S8) and serine carboxypeptidases (S10). The VCP1 group in the S8 tree shows evidence of gene duplication indicating recent adaptations to nutrient sources. Our results demonstrate that chitosan enhances Pc infectivity of nematode eggs through increased proteolytic activities and appressoria formation and might be used to improve the efficacy of M. javanica biocontrol.
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Use of light and scanning electron microscopy to examine colonisation of barley rhizosphere by the Nematophagous Fungus Verticillium chlamydosporium
Micron (Oxford England : 1993), 2002Co-Authors: Luis Vicente Lopez-llorca, J.j Bordallo, Jesús Salinas, Elena Monfort, M.l López-sernaAbstract:Barley roots were readily colonised by the Nematophagous Fungus Verticillium chlamydosporium. Light microscopy (LM) but also low temperature scanning electron microscopy (LTSEM) revealed details of the colonisation process. Hyphae were found on the rhizoplane often with dictyochlamydospores. Hyphae of V. chlamydosporium penetrated epidermal cells, often by means of appressoria. A hyphal network was formed in epidermal and cortical cells. Likewise, hyphal coils were found within root cells next to transverse cell walls. Cortical cells were the limits of fungal colonisation, since no hyphae were seen in the vascular cylinder. Modifications of root cell contents (phenolic droplets and callose appositions) were common three weeks after inoculation with V. chlamydosporium. These features may indicate induction of plant defence reactions in late stages of root colonisation by the Fungus. Both LTSEM and LM have proved extremely useful to describe root colonisation by the Fungus. The results found may have implications in the mode action of Nematophagous fungi against plant parasitic nematodes.
