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URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11847
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Item Nematicidal activity of Paecilomyces marquandii proteases on infective larvae of Ancylostoma spp(Brazilian Archives of Biology and Technology, 2016-01) Genier, Hugo Leonardo André; Queiroz, José Humberto de; Braga, Fabio Ribeiro; Soares, Filippe Elias de Freitas; Araújo, Jackson Victor de; Pinheiro, Iara RebouçasThe present study aimed to evaluate the action of Paecilomyces marquandii proteases on Ancylostoma spp L3. White halos in the zymogram confirmed the proteolytic action. Difference (p <0.01) between the number of L3 in the differents groups was found, with 41.4% of reduction of Ancylostoma spp. L3 before 24 hours.Item Characterization of a heat-resistant extracellular protease from Pseudomonas fluorescens 07A shows that low temperature treatments are more effective in deactivating its proteolytic activity(Journal of Dairy Science, 2016-10) Alves, Maura P.; Salgado, Rafael L.; Eller, Monique R.; Vidigal, Pedro Marcus P.; Carvalho, Antonio Fernandes deThis work discusses the biological and biochemical characterization of an extracellular protease produced by Pseudomonas fluorescens. The enzyme has a molecular weight of 49.486 kDa and hydrolyzes gelatin, casein, and azocasein, but not BSA. Its maximum activity is found at 37°C and pH 7.5, but it retained almost 70% activity at pH 10.0. It was shown to be a metalloprotease inhibited by Cu2+, Ni2+, Zn2+, Hg2+, Fe2+, and Mg2+, but induced by Mn2+. After incubation at 100°C for 5 min, the enzyme presented over 40% activity, but only 14 to 30% when submitted to milder heat treatments. This behavior may cause significant problems under conditions commonly used for the processing and storage of milk and dairy products, particularly UHT milk. A specific peptide sequenced by mass spectrometer analysis allowed the identification of gene that encodes this extracellular protease in the genome of Pseudomonas fluorescens 07A strain. The enzyme has 477 AA and highly conserved Ca2+- and Zn2+-binding domains, indicating that Ca2+, the main ion in milk, is also a cofactor. This work contributes to the understanding of the biochemical aspects of enzyme activity and associates them with its sequence and structure. These findings are essential for the full understanding and control of these enzymes and the technological problems they cause in the dairy industry.Item The nematophagous fungus Monacrosporium thaumasium and its nematicidal activity on Angiostrongylus vasorum(Revista Iberoamericana de Micología, 2013-09-24) Soares, Filippe Elias de Freitas; Braga, Fabio Ribeiro; Araújo, Jackson Victor de; Lima, Walter dos Santos; Queiroz, José Humberto deThe dog acts as a reservoir and environmental disseminator of potentially zoonotic parasites. The objective of this work was to study the fungus Monacrosporium thaumasium regarding its nematicidal potential in laboratory trials and its proteolytic profile. 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. There was a reduction (p < 0.01) in the averages of larvae recovered from the treated groups (conidia and crude extract) in relation to control groups. The zymogram suggested that the nematophagous fungus M. thaumasium produces a protease of approximately 40 kDa. 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 L1. 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 L1 of this nematode.Item Proteolytic activity of the nematophagous fungus Arthrobotrys sinensis on Angiostrongylus vasorum larvae(BMC Research Notes, 2014-11-18) Soares, Filippe Elias de Freitas; Queiroz, José Humberto de; Braga, Fabio Ribeiro; Araújo, Jackson Victor de; Lima, Walter dos Santos; Zamprogno, Tatiana ToniniThe 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.Item Optimization of protease production by the fungus Monacrosporium thaumasium and its action againstAngiostrongylus vasorum larvae(Revista Brasileira de Parasitologia Veterinária, 2012-09-20) Soares, Filippe Elias de Freitas; Queiroz, José Humberto de; Braga, Fabio Ribeiro; Araújo, Jackson Victor de; Lima, Walter dos Santos; Mozzer, Lanuze RoseThe objectives of this study were to optimize protease production from the nematophagous fungus Monacrosporium thaumasium (NF34a) and evaluate its larvicidal activity and biological stability. An isolate of the nematophagous fungus Monacrosporium thaumasium (NF34a) was used to produce the enzyme. The Plackett-Burman design was used in order to scan which components of the culture medium could have a significant influence on protease production by the fungus NF34a. An in vitro assay was also performed to evaluate the larvicidal activity of NF34a. It was observed that only one component of the culture medium (yeast extract), at the levels studied, had any significant effect (p < 0.05) on protease production. There was a reduction (p < 0.01) in the mean number of larvae recovered from the treated groups, compared with the control groups. The results confirm previous reports on the efficiency of nematophagous fungi for controlling nematode larvae that are potentially zoonotic. Thus, given the importance of biological control, we suggest that further studies should be conducted on the protease produced by the fungus Monacrosporium thaumasium.