997 resultados para Brazilian plant extract


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The filamentous fungus Aspergillus terreus secretes both invertase and beta-glucosidase when grown under submerged fermentation containing rye flour as the carbon source. The aim of this study was to characterize the co-purified fraction, especially the invertase activity. An invertase and a beta-glucosidase were co-purified by two chromatographic steps, and the isolated enzymatic fraction was 139-fold enriched in invertase activity. SDS-PAGE analysis of the co-purified enzymes suggests that the protein fraction with invertase activity was heterodimeric, with subunits of 47 and 27 kDa. Maximal invertase activity, which was determined by response surface methodology, occurred in pH and temperature ranges of 4.0-6.0 and 55-65 A degrees C, respectively. The invertase in co-purified enzymes was stable for 1 h at pH 3.0-10.0 and maintained full activity for up to 1 h at 55 A degrees C when diluted in water. Invertase activity was stimulated by 1 mM concentrations of Mn2+ (161 %), Co2+ (68 %) and Mg2+ (61 %) and was inhibited by Al3+, Ag+, Fe2+ and Fe3+. In addition to sucrose, the co-purified enzymes hydrolyzed cellobiose, inulin and raffinose, and the apparent affinities for sucrose and cellobiose were quite similar (K-M = 22 mM). However, in the presence of Mn2+, the apparent affinity and V-max for sucrose hydrolysis increased approximately 2- and 2.9-fold, respectively, while for cellobiose, a 2.6-fold increase in V-max was observed, but the apparent affinity decreased 5.5-fold. Thus, it is possible to propose an application of this multifunctional extract containing both invertase and beta-glucosidase to degrade plant biomass, thus increasing the concentration of monosaccharides obtained from sucrose and cellobiose.

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Conveyor belts are widely used in food handling areas, especially in poultry processing plants. Because they are in direct contact with food and it is a requirement of the Brazilian health authority, conveyor belts are required to be continuously cleaned with hot water under pressure. The use of water in this procedure has been questioned based on the hypothesis that water may further disseminate microorganisms but not effectively reduce the organic material on the surface. Moreover, reducing the use of water in processing may contribute to a reduction in costs and emission of effluents. However, no consistent evidence in support of removing water during conveyor belt cleaning has been reported. Therefore, the objective of the present study was to compare the bacterial counts on conveyor belts that were or were not continuously cleaned with hot water under pressure. Superficial samples from conveyor belts (cleaned or not cleaned) were collected at three different times during operation (T1, after the preoperational cleaning [5 a.m.]; T2, after the first work shift [4 p.m.]; and T3, after the second work shift [1:30 a.m.]) in a poultry meat processing facility, and the samples were subjected to mesophilic and enterobacterial counts. For Enterobacteriaceae, no significant differences were observed between the conveyor belts, independent of the time of sampling or the cleaning process. No significant differences were observed between the counts of mesophilic bacteria at the distinct times of sampling on the conveyor belt that had not been subjected to continuous cleaning with water at 45 degrees C. When comparing similar periods of sampling, no significant differences were observed between the mesophilic counts obtained from the conveyor belts that were or were not subjected to continuous cleaning with water at 45 degrees C. Continuous cleaning with water did not significantly reduce microorganism counts, suggesting the possibility of discarding this procedure in chicken processing.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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A high incidence of plants with mosaic, chlorotic spots, ringspots, necrosis, smaller leaves, and stunting was observed on peanut crops (Arachis hypogaea L.) in Itapolis, So Paulo State, Brazil. Transmission electron microscope examination of thin sections of infected leaves revealed the presence of spheroidal particles, ca. 80 nm in diameter, suggestive of Tospovirus. A DNA fragment of similar to 600 bp was amplified by RT-PCR from total RNA extracted from infected tissues using primers specific for the nucleocapsid gene of Groundnut ringspot virus (GRSV). Nucleotide and deduced amino acid sequences of the fragments showed high identities with known GRSV isolates.

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Brazilian Campos grasslands are ecosystems under high frequency of disturbance by grazing and fires. Absence of such disturbances may lead to shrub encroachment and loss of plant diversity. Vegetation regeneration after disturbance in these grasslands occurs mostly by resprouting from belowground structures. We analyzed the importance of bud bank and belowground bud bearing organs in Campos grasslands. We hypothesize that the longer the intervals between disturbances are, the smaller the size of the bud bank is. Additionally, diversity and frequency of belowground organs should also decrease in areas without disturbance for many years. We sampled 20 soil cores from areas under different types of disturbance: grazed, exclusion from disturbance for two, six, 15 and 30 years. Belowground biomass was sorted for different growth forms and types of bud bearing organs. We found a decrease in bud bank size with longer disturbance intervals. Forbs showed the most drastic decrease in bud bank size in the absence of disturbance, which indicates that they are very sensitive to changes in disturbance regimes. Xylopodia (woody gemmiferous belowground organs with hypocotyl-root origin) were typical for areas under influence of recurrent fires. The diversity of belowground bud bearing structures decreased in the absence of disturbance. Longer intervals between disturbance events, resulting in decrease of bud bank size and heterogeneity of belowground organs may lead to the decline and even disappearance of species that relay on resprouting from the bud bank upon disturbance. (C) 2014 Elsevier GmbH. All rights reserved.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The study of allelopathic activity has been aim of research that evaluates mainly species used in green fertilization. Raphanus sativus L. stands out among these species, because it shows high capacity for nutrient recycling, specially nitrogen and phosphorus, what makes it an advantageous cover plant in crop rotation systems. Considering the exposed, the present study had as objective the evaluation of the allelopathic and phytotoxic potentials of different concentrations of the R. sativus leaves ethanolic extract by mean of seeds germination analyses and development of lettuce seedlings, evaluating the phytotoxicity by determination of the mitotic index of lettuce root cells, realizing the phytochemical profile and investigating the antioxidant activity. It was possible to verify that the R. sativus extract interferes in the germination index, decreasing the germinability (5 mg. mL(-1) = 9.84%; 10 mg. mL(-1) = 11.91% and 20 mg. mL(-1)= 57.51%). In the lettuce seedlings growth, the extract of this species affected the roots and hypocotyls growth. It was possible to observe phenols and total flavonoids in the extract for the concentration of 1000 mu g. mL(-1)(161mg and 83.57 mg, respectively). It was also observed, higher antioxidant activity for the concentration of 1000 mu g. mL(-1) (89.76%). In the phytotoxicity assay was observed a dose dependent effect in the mitotic index and in the cellular events during cellular division. In this study it was possible to conclude that this species has allelochemical compounds which are able to interfere directly on the stabilization and development of other species.