Navegando por Autor "Soares, Filippe E. F."
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Item In vitro activity of a serine protease from Monacrosporium thaumasium fungus against first-stage larvae of Angiostrongylus vasorum(Parasitology Research, 2012-01-10) Braga, Fabio R.; Araújo, Jackson V.; Soares, Filippe E. F.; Lima, Walter dos Santos; Mozer, Lanuze R.; Queiróz, José H.A serine protease from the nematophagous fungus Monacrosporium thaumasium (NF34a) was purified, partially characterized and tested in vitro in control of the first larval stage of Angiostrongylus vasorum. NF34a grew in liquid culture medium, producing its crude extract that was purified by ion exchange chromatography. The fractions with high protease activity were collected in a pool, and elution of proteases was monitored by enzymatic assay and protein content. Purification steps were monitored by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Protease activity was determined under different pH and temperature conditions, and the inhibitor effects of metal ions and phenylmethylsulfonyl fluoride (PMSF) were assessed. In an experimental test, the infection process of NF34a on first-stage larvae of A. vasorum was investigated. A purified serine protease (Mt1) was identified, with an approximate molecular mass of 40 kDa and apparent homogeneity in SDS-PAGE, having optimal activity at pH 7.0 to 8.0 and temperature of 60°C. Mg2+ and Zn2+ partially inhibited the activity of Mt1 while PMSF inhibited it completely. Mt1 production was observed when NF34a was grown using first-stage larvae of A. vasorum as the only source of carbon and nitrogen. These results show that the enzyme may have a possible role in the infection process of the larvae. In the in vitro test of applicability against A. vasorum L1, we observed a reduction in the number of larvae of 23.9% (p < 0.05) in the group treated with Mt1 compared with the control group. However, even this low reduction demonstrates that the Mt1 is important in the infection process.Item Nematicidal activity of three novel extracellular proteases of the nematophagous fungus Monacrosporium sinense(Parasitology Research, 2013-01-31) Soares, Filippe E. F.; Braga, Fabio R.; Araújo, Jackson V.; Geniêr, Hugo L. A.; Gouveia, Angélica S.; Queiroz, José H.Extracellular proteases are an important virulence factor for the nematophagous fungi Monacrosporium. The objective of this study was to optimize, purify, partially characterize, and to evaluate the nematicidal activity of the proteases produced by the nematophagous fungus Monacrosporium sinense (SF53) by solid-state fermentation. Wheat bran was used as substrate for protease production. The variables moisture, pH, incubation time, temperature, glucose, yeast extract, and the number of conidia were tested for their influences on protease production by SF53. To determine the optimal level of the selected variables the central composite design was applied. The crude extract obtained was purified in two steps, an ion exchange chromatography and a gel excision. SDS-PAGE and zymogram were performed for analysis of the purification process. Proteolytic activity was also tested at different pHs and temperatures. In the in vitro assay, the nematicidal activity of the three proteases was evaluated. pH and incubation time showed a significant effect (p < 0.05) on production of protease. The highest value of activity was 38.0 (U/ml) under the conditions of pH 5.0 and incubation time of 211 h. SF53 produced three different proteases (Ms1, Ms2, and Ms3) which were directly purified from the zymogram. Ms1, Ms2, and Ms3 showed the following percentage of reduction (p < 0.05) on the number of Panagrellus redivivus compared to control after 24 h: 76.8, 68.1, and 92.1 %. This is the first report of the use of proteases of the isolate SF53 on a phytonematode, which may be a research tool in future works.Item Otimização do pré-tratamento hidrotérmico da palha de cana-de-açúcar visando à produção de etanol celulósico(Química Nova, 2013-08-21) Santos, Fernando A.; Queiroz, José H. de; Colodette, Jorge L.; Manfredi, Mauro; Queiroz, Maria Eliana L. R.; Caldas, Celso S.; Soares, Filippe E. F.The sugarcane industry has huge potential for biorefinery concept application, given its development in recent years. In this context, cane sugar straw has become an attractive raw material for biofuel production. This study aims to investigate the chemical composition of cane sugar straw from different regions of Brazil, and to optimize a hydrothermal pretreatment stage for cellulosic ethanol production. Results of chemical characterization of the cane sugar straw for the regions assessed indicated little influence of place on straw chemical composition. Hydrothermal pretreatment showed high efficiency in hemicellulose removal. Hydrothermal pretreatments operating with temperatures of 190 and 210 oC presented satisfactory results, reaching values close to 100% hydrolysis.Item Predatory capability of the nematophagous fungus Arthrobotrys robusta preserved in silica gel on infecting larvae of Haemonchus contortus(Tropical Animal Health and Production, 2014-02-08) Braga, Fabio R.; Carvalho, Rogério O.; Silva, André R.; Araújo, Jackson V.; Frassy, Luiza N.; Lafisca, Andrea; Soares, Filippe E. F.Biological control of gastrointestinal nematodiasis in ruminants is an alternative to reduce the number of infective larvae. The fungal isolates predatory activity preservation is a basic requirement for the success of this control type. The aim of this work is to evaluate the predatory capacity of the fungus Arthrobotrys robusta (isolate I-31), preserved on silica gel on infective larvae of Haemonchus contortus under laboratory conditions on 2 % water agar (2 % WA). In this essay, A. robusta storage on silica gel showed successful predatory activity on H. contortus L3 larvae (p < 0.01) compared to the control group. Nematophagous fungi were not observed in the control group during the experiment. There was a significant reduction (p < 0.01) of 73.84 % in the means of H. contortus (L3) recovered from treatment with isolate I-31 compared to the control without fungi. Results indicate that A. robusta (I-31) could survive stored on silica gel for at least 7 years and keep its predatory activity on H. contortus (L3).