378 resultados para Penicillium digitatum
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Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE
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Coffee husk is an abundant by-product generated by the coffee industry and it can be used for the production of-value-added phenolic compounds. Currently, this residue has no commercial use due to the presence of anti-nutritional compounds and it is returned to the soil or burned. The aim of this study was to evaluate the content of phenolic compounds in Robusta coffee husk, the adequacy of this residue as substrate for fermentation processes, as well as evaluating the influence of fungal solid state fermentation to obtain phenolic compounds from this residue. In the present study, the use of different solvents for the extraction of polyphenols was evaluated and the content was found to be in the range of 96.9-159.5 mg of galic acid (GA).g(-1) substrate, depending on the solvent used. The best solvent was acetone, therefore it was selected for extraction. Studies were carried out to evaluate the effect of solid-state fermentation in the release of phenolic compounds, using the filamentous fungi Penicillium purpurogenum. The total phenolic content increased from 159.5 up to 243.2 mg GA.g(-1) substrate as a result the solid-state fermentation.
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A survey to determine population trends and entomopathogenic fungi associated with the red palm mite (RPM), Raoiella indica, was conducted in Trinidad, Antigua, St. Kitts and Nevis and Dominica. RPM population density was evaluated by sampling a total of ten coconut palms per site in Antigua, St. Kitts and Nevis, Dominica, and Trinidad (Manzanilla and Icacos). Mites from the four islands were either surface sterilized or left unsterilized before being cultured on Tap Water Agar (TWA). A total of 318 fungal colonies were retrieved. A further 96 mites from Dominica were kept on sterile moist filter paper in a humidity chamber and a further 85 colonies were isolated. Based on morphological observations of all 403 isolates, a sample consisting of 32 colonies (8 %) was sent for identification at CABI-UK. Of the 27 fungi positively identified, 15 isolates belonged to the genera Cladosporium, three to Simplicillium spp., and one to Penicillium. Other fungi genera with limited or no entomopathogenic potential included: Aspergillus, Cochliobolus, Fusarium, Pestalotiopsis and Pithomyces. The results show a potential use of entomopathogenic fungi for population management of the red palm mite in the Caribbean region.
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Birds are hosts for a rich fungal microbiota which can act as potent pathogens for humans and other species of animals, causing thereby serious public health problems. The objective of this study was to evaluate the participation of birds kept in containers in the epidemiology of infectious diseases such as cryptococcosis and aspergillosis, thus verifying the maintenance and spread of pathogens in the environment. 36 samples of excretas of passeriformes were collected and were cultivated in Sabouraud Dextrose Agar 4% at room temperature and 37°C. The isolated fungal colonies were classified according to their morphological and staining characteristics. Subsequently, those in yeast form were peaked in Niger Agar, incubated at 30°C. In one sample showed growth of more than one type of colony and there was verified the presence of 25.0% of Penicillium spp., 19.4% of Trichosporon spp., 13.9% of C. gattii, 11.1% of C. neoformans, 11.1% of Candida spp., 8.3% of Rhizomucor spp., 8.3% of Aspergillus spp., 2.8% of Nigrospora spp. and 2,8% of Geotrichum spp. It can be conluded by the expost that birds shed continuously pathogenic microorganisms in their feces acting in definitive form in the infectious diseases ecoepidemiology.
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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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The purpose of treating seeds chemically is to eradicate their pathogens and/or protect them against soil pathogens, mainly by germination time. However, there is little research on vegetables investigating the effect of this treatment on seed quality. Therefore, this study evaluates the effects of Carboxin + Thiram doses on germination and vigor of three lots of broccoli seeds, as well as on the incidence of fungi in treated seed. The 15 treatments were evaluated in a factorial system (3x5), with the first factor consisting of three lots of 'Avenger' broccoli seeds (lots 82744, 82745 and 82749), and the second factor consisting of five doses (0, 0.04, 0.06, 0.10 and 0.12% of a.i.) of Carboxin + Thiram fungicide (commercial name Vitavax-Thiran). The germination and seed vigor were evaluated, in addition to the presence of pathogens in seeds after treatment (blotter test). All lots showed high levels of germination and vigor. The lot 82749, however, showed higher value in plug test in substrate emergence (99%) than lot 82745 (95%). Regarding the treatment with Carboxin + Thiram, no changes in germination average (98%) and vigor were noticed (average for the first germination count, length, and dry weight of seedling, plug test at 10 days after sowing of 97%, 4.9 cm, 4.0 mg and 96%, respectively), showing that this fungicide, in the evaluated doses, does not affect the quality of broccoli seeds. As to seeds health, the pathogens Alternaria spp. and Fusarium spp. were detected, in addition to saprophytic species such as Penicillium, Aspergillus, Trichoderma, and Rhizopus. The higher incidence of Fusarium spp. was noticed in lot 82744, and the lowest in lot 82749. As to Penicillium spp., lot 82479 was the most contaminated. Regarding other fungi, the general incidence was very low and there was no difference between lots and doses used.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Black fungi are able to adapt to extreme environmental conditions, such as: high temperatures, the presence of toxic chemical substances and lack of nutrients. Besides, they are also potential pathogens to humans. The natural environment of many black fungi is still unknown and some studies are being conducted to evaluate the biodiversity of this group and their different habitats. This study aimed to isolate black fungi in domestic environments and facilities, such as toothbrushes, fridge sealing rubbers, bathroom strainers and divisions, windows, wall tiles and bath sponge. For the collection, material surfaces were scratched with a scalpel and the resulting fragments were sewed in Mycosel agar (DifcoTM), supplemented with actidione to inhibit the growth of highly-sporulating fungi. Plates were incubated at 25ºC for three weeks. The 46 isolated fungi were maintained on MA2% slants at 8ºC and cryopreserved at -80ºC. Fungal identification was performed through the analysis of macro and microscopic features and ITS rDNA sequencing. The following black fungi taxa were found: Ascomycota sp., Cladosporium spp., Dothideomycete sp., Exophiala alcalophila, Ochroconis mirabilis and Rhinocladiella atrovirens. Non-melanized fungi were also found, such as Geosmithia sp., Penicillium sp. and Rhodotorula mucilaginosa. The temperature tests showed that isolated black fungi were not able to grow at 37°C, however, this temperature proved to be fungistatic to 43% of them. According to literature, all black fungi isolated in this study are opportunistic pathogens and additional studies are necessary to evaluate the risk that these micro-organisms offer to health, once they were isolated from domestic environments
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Pós-graduação em Ciências Biológicas (Microbiologia Aplicada) - IBRC
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Black fungi are able to adapt to extreme environmental conditions, such as: high temperatures, the presence of toxic chemical substances and lack of nutrients. Besides, they are also potential pathogens to humans. The natural environment of many black fungi is still unknown and some studies are being conducted to evaluate the biodiversity of this group and their different habitats. This study aimed to isolate black fungi in domestic environments and facilities, such as toothbrushes, fridge sealing rubbers, bathroom strainers and divisions, windows, wall tiles and bath sponge. For the collection, material surfaces were scratched with a scalpel and the resulting fragments were sewed in Mycosel agar (DifcoTM), supplemented with actidione to inhibit the growth of highly-sporulating fungi. Plates were incubated at 25ºC for three weeks. The 46 isolated fungi were maintained on MA2% slants at 8ºC and cryopreserved at -80ºC. Fungal identification was performed through the analysis of macro and microscopic features and ITS rDNA sequencing. The following black fungi taxa were found: Ascomycota sp., Cladosporium spp., Dothideomycete sp., Exophiala alcalophila, Ochroconis mirabilis and Rhinocladiella atrovirens. Non-melanized fungi were also found, such as Geosmithia sp., Penicillium sp. and Rhodotorula mucilaginosa. The temperature tests showed that isolated black fungi were not able to grow at 37°C, however, this temperature proved to be fungistatic to 43% of them. According to literature, all black fungi isolated in this study are opportunistic pathogens and additional studies are necessary to evaluate the risk that these micro-organisms offer to health, once they were isolated from domestic environments
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Pós-graduação em Ciências Biológicas (Microbiologia Aplicada) - IBRC
Marine Fungi Aspergillus sydowii and Trichoderma sp Catalyze the Hydrolysis of Benzyl Glycidyl Ether
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Whole cells of the marine fungi Aspergillus sydowii Gc12, Penicillium raistrickii Ce16, P. miczynskii Gc5, and Trichoderma sp. Gc1, isolated from marine sponges of the South Atlantic Ocean (Brazil), have been screened for the enzymatic resolution of (+/-)-2-(benzyloxymethyl)oxirane (benzyl glycidyl ether; 1). Whole cells of A. sydowii Gc12 catalyzed the enzymatic hydrolysis of (R,S)-1 to yield (R)-1 with an enantiomeric excess (ee) of 24-46% and 3-(benzyloxy)propane-1,2-diol (2) with ee values < 10%. In contrast, whole cells of Trichoderma sp. Gc1 afforded (S)-1 with ee values up to 60% and yields up to 39%, together with (R)-2 in 25% yield and an ee of 32%. This is the first published example of the hydrolysis of 1 by whole cells of marine fungi isolated from the South Atlantic Ocean. The hydrolases from the two studied fungi exhibited complementary regioselectivity in opening the epoxide ring of racemic 1, with those of A. sydowii Gc12 showing an (S) preference and those of Trichoderma sp. Gc1 presenting an (R) preference for the substrate.
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The scanning electron microscopy (SEM) analysis showed that whole living hyphal of marine fungi Aspergillus sclerotiorum CBMAI 849 and Penicillium citrinum CBMAI 1186 were immobilized on support matrices of silica gel, silica xerogel and/or chitosan. P. citrinum immobilized on chitosan catalyzed the quantitative reduction of 1-(4-methoxyphenyl)-ethanone (1) to the enantiomer (S)-1-(4-methoxyphenyl)-ethanol (3b), with excellent enantioselectivity (ee > 99%, yield = 95%). Interestingly, ketone 1 was reduced with moderate selectivity and conversion to alcohol 3b (ee = 69%, c 40%) by the free mycelium of P. citrinum. This free mycelium of P. citrinum catalyzed the production of the (R)-alcohol 3a, the antipode of the alcohol produced by the immobilized cells. P. citrinum immobilized on chitosan also catalyzed the bioreduction of 2-chloro-1-phenylethanone (2) to 2-chloro-1-phenylethanol (4a,b), but in this case without optical selectivity. These results showed that biocatalytic reduction of ketones by immobilization hyphal of marine fungi depends on the xenobiotic substrate and the support matrix used. (c) 2012 Elsevier B.V. All rights reserved.
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The screening. biomass growth of lipase-producing fungus isolated from different sources and available at URM (University Recife Mycologia). as well as, the immobilization and utilization of the whole cells for the transesterification of babassu oil were investigated. Rhizopus oryzae (URM 3231, 4692), Mucor circinelloides (URM 4140, 4182) and Penicillium citrinum URM 4216 were considered to be good intracellular lipase producers whereas those from Mucor hiemalis URM 4144 and Mucor piriformis URM 4145 were weaker. Fungi biomass containing high lipase activities was immobilized on different biomass support particles (BSPs) and with the exception of Penicillium citrinum URM 4216 all the other fungi strains exhibited high lipase activity (20-50 Ug(-1)) when immobilized in situ using polyurethane foam particles. Transesterification activities of the immobilized whole cells were evaluated in the ethanolysis reaction with babassu oil and the highest performance was attained by M. circinelloides URM 4182 giving 83.22 +/- 3.68% ester yield in less than 96 h reaction. The biocatalyst operational stability was also assessed and an inactivation profile was found to follow the Arrhenius model, revealing values of 26 days and 2.6 x 10(-2)day(-1), for half-life and a deactivation coefficient, respectively. The purified product (biodiesel) exhibited viscosity (6.63 cSt) close to the value to attend specifications by the ASTM 06751 to be used as biofuel. Results are favorable compared with data already reported in the literature and demonstrated that M. circinelloides URM 4182 whole cells is a cheaper biocatalyst that can be used in the biodiesel synthesis. (C) 2012 Elsevier B.V. All rights reserved.