972 resultados para ASPERGILLUS SPP


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A freqüência de contaminação de parques e praças públicas de Botucatu, São Paulo, Brasil, por ovos de Toxocara spp foi estudada durante 12 meses, com colheitas mensais de amostras de solo de dez praças, que foram processadas pela técnica de concentração em solução decinormal de hidróxido de sódio. Das 120 amostras analisadas, 21 estavam contaminadas, correspondendo a 17,5%, em um total de seis praças. A maioria desses ovos porém apresentaram características de inviabilidade infectiva. Embora a chance de aquisição dessa zoonose nas praças estudadas seja pequena, existe o risco de infecção da população.

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Five species of titi monkey (Callicebus brunneus, Callicebus caligatus, Callicebus cinerascens, Callicebus donacophilus, and Callicebus moloch) were recorded in surveys of primate populations at 26 sites throughout the Brazilian state of Rondonia. The distribution of the two species, C. cinerascens and C. donacophilus (recorded in the state for the first time), appeared to be related to that of non-forest ecosystems, the former in the cerrado woodlands, and the latter in gallery forests of the Guapore grasslands. The results of the surveys also indicate that C. brunneus has a more restricted distribution in southern Rondonia than was previously thought, whereas C. moloch is more widespread. However, the ecological factors that determine species distribution in the south of the state remain unclear on the basis of the available data. All species were observed in small social groups of no more than five individuals, which are typical of the genus, generally in the middle and lower forest strata.

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Pathogenic variation in Colletotrichum gloeosporioides infecting species of the tropical pasture legume Stylosanthes at its center of diversity was determined from 296 isolates collected from wild host population and selected germ plasm of S. capitata, S. guianensis, S. scabra, and S. macrocephala in Brazil. A putative host differential set comprising 11 accessions was selected from a bioassay of 18 isolates on 19 host accessions using principal component analysis. A similar analysis of anthracnose severity data for a subset of 195 isolates on the 11 differentials indicated that an adequate summary of pathogenic variation could be obtained using only five of these differentials. of the five differentials, S. seabrana 'Primar' was resistant and S. scabra 'Fitzroy' was susceptible to most isolates. A cluster analysis was used to determine eight natural race clusters using the 195 isolates. Linear discriminant functions were developed for eight race clusters using the 195 isolates as the training data set, and these were applied to classify a test data set of the remaining 101 isolates. All except 11 isolates of the test data set were classified into one of the eight race clusters. Over 10% of the 296 isolates were weakly pathogenic to all five differentials and another 40% were virulent on just one differential. The unclassified isolates represent six new races with unique virulence combinations, of which one isolate is virulent on all five differentials. The majority of isolates came from six field sites, and Shannon's index of diversity indicated considerable variation between sites. Pathogenic diversity was extensive at three sites where selected germ plasm were under evaluation, and complex race clusters and unclassified isolates representing new races were more prevalent at these sites compared with sites containing wild Stylosanthes populations.

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After exposure of Solenopsis saevissima colonies maintained in plastic trays to phorid attack in the field, and subsequent transfer of colonies to covered plastic buckets, we confirmed that P. wasmanni and P. litoralis are indeed parasitoids of fire ant workers. The period from attack to emergence of phorid adults ranged from 35 to 46 days. Adult phorids were maintained live in glass vials with sugar water as a food source for 5 days. These results indicate that Pseudaceton can be reared for biological control release programs with minimal difficulty. Furthermore, parasitized workers could be easily transferred from South America to quarantine laboratories within the egg to adult emergence time period.

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The purpose of this study was to isolate yeast (Candida) from the quarter milk of cow udders from 37 dairy farms in Brazil and to identify the different species involved in mastitis. The samples were collected between October 2002 and February 2003. Two-hundred-and-sixty milk samples from cows with clinical and subclinical mastitis were examined. Milk samples were plated onto Blood agar, Mac Conkey agar and Sabouraud dextrose agar. Forty-five (17.3%) samples were positive for the genus Candida. The Candida species isolated were C. krusei (44.5%), C. rugosa (24.5%), C. albicans (8.9%), C. guilliermondii (8.9%), and others (13.2%). We also isolated Escherichia coli (26.5%), coagulase-positive Staphylococcus (25.0%), Streptococcus spp. (8.1%), Enterobacter spp. (8.1%), and other fungi (8.1%), among others.

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This work describes fructose oligosaccharide (FOS) production by the immobilized mycelia (IM) of a strain of Aspergillus japonicus, isolated from soil. The microorganism was inoculated into 50 mi of medium composed of sugar cane molasses (5.0% of total sugars); yeast powder; 2.0%; K2HPO4, 0.5%; NaNO3, 0.2%; MgSO4. 7H(2)O, 0.05%; KCl, 0.05%, final pH 5.0, and the flasks were agitated in an orbital shaker at 200 rpm for 60 h, at 30 degrees C. The beta-fructofuranosidase activity (Uf), transfructosylating activity (Ut), hydrolyzing activity (Uh), and FOS production were analyzed by high performance liquid chromatography. FOS production was performed in a batch process in a 2-l jar fermenter by IM in calcium alginate beads. The optimum pH and temperature were 5.0-5.6 and 55 degrees C, respectively No loss of activity was observed when the mycelium was maintaned at 60 degrees C for 60 min. Maximum production was obtained using 5.75% (cellular weight/volume) of mycelia (122.4 Ut g(-1)) and 65% sucrose solution (w:v) for 4 h of reaction when the final product reached 61.28% of fetal FOS containing GF(2) (30.56%), GF(3) (26.45%), GF(4) (4.27%), sucrose (9.6%) and glucose (29.10%). In the assay conditions, 23 batches were performed without loss of activity of the IM, showing that the microorganism and the process utilized have potential for industrial applications. (C) 1998 Elsevier B.V. Ltd. All rights reserved.

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An endoxylanase (beta-1,4-xylan xylanohydrolase, EC 3.2.1.8) was purified from the culture filtrate of a strain of Aspergillus versicolor grown on oat wheat. The enzyme was purified to homogeneity by chromatography on DEAE-cellulose and Sephadex G-75. The purified enzyme was a monomer of molecular mass estimated to be 19 kDa by SDS-PAGE and gel filtration. The enzyme was glycoprotein with 71% carbohydrate content and exhibited a pI of 5.4. The purified xylanase was specific for xylan hydrolysis. The enzyme had a K-m of 6.5 mg ml(-1) and a V-max of 1440 U (mg protein)(-1). (C) 1998 Federation of European Microbiological Societies. Published by Elsevier B.V. B.V. All rights reserved.

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Sera from 961 horses from Brazil were tested for antibodies against the major surface antigens SnSAG4 and NhSAG1 to determine the seroprevalence of Sarcocystis neurona and Neospora hughesi, respectively. Antibodies against SnSAG4 were detected in 669 (69.6%) of the horses, while antibodies against NhSAG1 were detected in only 24 (2.5%) of the horses. These serologic results suggest that there is a high concentration of S. neurona in the environment of Brazil, which results in marked exposure of horses to this parasite. Additionally, the data further confirm that infection with Neospora spp. is relatively uncommon in horses. (c) 2005 Elsevier B.V. All tights reserved.

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Different concentrations of sucrose (3-25% w/v) and peptone (2-5% w/v) were studied in the formulation of media during the cultivation of Aspergillus japonicus-FCL 119T and Aspergillus niger ATCC 20611. Moreover, cane molasses (3.5-17.5% w/v total sugar) and yeast powder (1.5-5% w/v) were used as alternative nutrients for both strains' cultivation. These media were formulated for analysis of cellular growth, P-Fructosyltransferase and Fructooligosaccharides (FOS) production. Transfructosylating activity (U-t) and FOS production were analyzed by HPLC. The highest enzyme production by both the strains was 3% (w/v) sucrose and 3% (w/v) peptone, or 3.5% (w/v) total sugars present in cane molasses and 1.5% (w/v) yeast powder. Cane molasses and yeast powder were as good as sucrose and peptone in the enzyme and FOS (around 60% w/w) production by studied strains.

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This study reports on the effects of growth temperature on the secretion and some properties of the xylanase and beta-xylosidase activities produced by a thermotolerant Aspergillus phoenicis. Marked differences were observed when the organism was grown on xylan-supplemented medium at 25 degreesC or 42 degreesC. Production of xylanolytic enzymes reached maximum levels after 72 h of growth at 42 degreesC; and levels were three- to five-fold higher than at 25 degreesC. Secretion of xylanase and beta-xylosidase was also strongly stimulated at the higher temperature. The optimal temperature was 85 degreesC for extracellular and 90 degreesC for intracellular beta-xylosidase activity, independent of the growth temperature. The optimum temperature for extracellular xylanase increased from 50 degreesC to 55 degreesC when the fungus was cultivated at 42 degreesC. At the higher temperature, the xylanolytic enzymes produced by A. phoenicis showed increased thermo stability, with changes in the profiles of pH optima. The chromatographic profiles were distinct when samples obtained from cultures grown at different temperatures were eluted from DEAE-cellulose and Biogel P-60 columns.

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Aspergillus niger on paramorphogenic form showed to be efficient adsorbent to reactive azo dye Procion Blue MX-G, where it has obtained rates of colour removal above 99% in acid pH, at 120 minutes of equilibrium time. Temperature did not exert expressive influence in the process, and the applicability of Freundlich's, isotherm suggest the occurrence of various molecules layers of adsorbed dye on the substratum surface.

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Brazilian isolates of Colletotrichum spp. from citrus orchards affected by postbloom fruit drop were examined for colony colour, mycelial growth, benomyl-resistance, pathogenicity, and genetic variability by random amplified polymorphic DNA (RAPD) analysis. All isolates were obtained from flowers and persistent calyxes from different citrus hosts from São Paulo, Brazil. DNA polymorphisms detected after amplification with random 10-mer primers were used to classify the isolates into two groups. Group I isolates grew rapidly on potato-dextrose agar (PDA) and were sensitive to benomyl, and group II isolates grew slowly on PDA and were benomyl-resistant. Colletotrichum acutatum was analyzed by RAPD and had high genetic similarity with group II isolates of Colletotrichum from citrus. Probably, the group I is C, gloeosporioides and group II is C. acutatum.