555 research outputs found

    Produção de mudas micropropagadas de mandioca (Manihot esculenta Crantz) em larga escala: uma inovação tecnológica.

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    Um protocolo e inovador para a micropropagação em escala comercial da mandioca foi estabelecido pelo Instituto Biofábrica de Cacau, localizado em Ilhéus, Bahia, Brasil. Os procedimentos utilizados para a realização do processo de produção de mudas de mandioca em escala comercial apresentam elevados padrões técnicos, tais como, fidelidade genética e alta qualidade fitossanitária. As elevadas taxas demortalidade verificada em apenas cinco das 31 variedades multiplicadas estão relacionadas diretamente ao genótipo, ao ambiente in vitro e a diversos fatores que podem influenciar na aclimatização das mudas micropropagadas. O manejo adequado da irrigação, isto é, a quantidade de água e a frequência de aplicação, possibilita o desenvolvimento vigoroso das mudas micropropagadas, otimizando o processo de aclimatização. No entanto, mesmo o sistema apresentando uma eficiência muito grande, existe a preocupação em se adotar medidas para reduzir os custos e aprimorar a produção de mudas micropropagadas de mandioca com qualidade genética e fitossanitária, bem como o procedimento de multiplicação rápida a partir de plantas enviveirada

    Development and evaluation of antimicrobial and modulatory activity of inclusion complex of euterpe oleracea mart oil and \u3b2-cyclodextrin or HP-\u3b2-cyclodextrin

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    The development of inclusion complexes is used to encapsulate nonpolar compounds and improve their physicochemical characteristics. This study aims to develop complexes made up of Euterpe oleracea Mart oil (EOO) and \u3b2-cyclodextrin (\u3b2-CD) or hydroxypropyl-\u3b2-cyclodextrin (HP-\u3b2-CD) by either kneading (KND) or slurry (SL). Complexes were analyzed by molecular modeling, Fourier-transform infrared spectroscopy, scanning electron microscopy, powder X-ray diffraction, thermogravimetry analysis and differential scanning calorimetry. The antibacterial activity was expressed as Minimum Inhibitory Concentration (MIC), and the antibiotic resistance modulatory activity as subinhibitory concentration (MIC/8) against Escherichia coli, Streptomyces aureus, Pseudomonas aeruginosa and Enterococcus faecalis. Inclusion complexes with \u3b2-CD and HP-\u3b2-CD were confirmed, and efficiency was proven by an interaction energy between oleic acid and \u3b2-CD of 1241.28 \ub1 0.57 kJ/mol. MIC values revealed higher antibacterial activity of complexes compared to the isolated oil. The modulatory response of EOO and EOO-\u3b2-CD prepared by KND as well as of EOO-\u3b2-CD and EOO-HP-\u3b2-CD prepared by SL showed a synergistic effect with ampicillin against E. coli, whereas it was not significant with the other drugs tested, maintaining the biological response of antibiotics. The antimicrobial response exhibited by the complexes is of great significance because it subsidizes studies for the development of new pharmaceutical forms

    Mycobacterium leprae Recombinant Antigen Induces High Expression of Multifunction T Lymphocytes and Is Promising as a Specific Vaccine for Leprosy

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    Leprosy is a chronic disease caused by M. leprae infection that can cause severe neurological complications and physical disabilities. A leprosy-specific vaccine would be an important component within control programs but is still lacking. Given that multifunctional CD4 T cells [i.e., those capable of simultaneously secreting combinations of interferon (IFN)-γ, interleukin (IL)-2, and tumor necrosis factor (TNF)] have now been implicated in the protective response to several infections, we tested the hypothesis if a recombinant M. leprae antigen-specific multifunctional T cells differed between leprosy patients and their healthy contacts. We used whole blood assays and peripheral blood mononuclear cells to characterize the antigen-specific T cell responses of 39 paucibacillary (PB) and 17 multibacillary (MB) leprosy patients and 31 healthy household contacts (HHC). Cells were incubated with either crude mycobacterial extracts (M. leprae cell sonicate–MLCS) and purified protein derivative (PPD) or recombinant ML2028 protein, the homolog of M. tuberculosis Ag85B. Multiplex assay revealed antigen-specific production of IFN-γ and IL-2 from cells of HHC and PB, confirming a Th1 bias within these individuals. Multiparameter flow cytometry then revealed that the population of multifunctional ML2028-specific T cells observed in HHC was larger than that observed in PB patients. Taken together, our data suggest that these multifunctional antigen-specific T cells provide a more effective response against M. leprae infection that prevents the development of leprosy. These data further our understanding of M. leprae infection/leprosy and are instructive for vaccine development

    Hemoglobin Uptake by Paracoccidioides spp. Is Receptor-Mediated

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    Iron is essential for the proliferation of fungal pathogens during infection. The availability of iron is limited due to its association with host proteins. Fungal pathogens have evolved different mechanisms to acquire iron from host; however, little is known regarding how Paracoccidioides species incorporate and metabolize this ion. In this work, host iron sources that are used by Paracoccidioides spp. were investigated. Robust fungal growth in the presence of the iron-containing molecules hemin and hemoglobin was observed. Paracoccidioides spp. present hemolytic activity and have the ability to internalize a protoporphyrin ring. Using real-time PCR and nanoUPLC-MSE proteomic approaches, fungal growth in the presence of hemoglobin was shown to result in the positive regulation of transcripts that encode putative hemoglobin receptors, in addition to the induction of proteins that are required for amino acid metabolism and vacuolar protein degradation. In fact, one hemoglobin receptor ortholog, Rbt5, was identified as a surface GPI-anchored protein that recognized hemin, protoporphyrin and hemoglobin in vitro. Antisense RNA technology and Agrobacterium tumefaciensmediated transformation were used to generate mitotically stable Pbrbt5 mutants. The knockdown strain had a lower survival inside macrophages and in mouse spleen when compared with the parental strain, which suggested that Rbt5 could act as a virulence factor. In summary, our data indicate that Paracoccidioides spp. can use hemoglobin as an iron source most likely through receptor-mediated pathways that might be relevant for pathogenic mechanisms

    Production of enzymatic extract with high cellulolytic and oxidative activities by co-culture of Trichoderma reesei and Panus lecomtei.

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    This work aimed to produce enzymatic fungi extracts with hydrolytic and oxidative activities to hydrolyze lignocellulosic biomasses efficiently. For this, the fungi Trichoderma reesei and Panus lecomtei were co-cultured using the vegetable biomasses oil palm decanter cake, wheat bran, and cottonseed cake as substrates in submerged fermentation. T. reesei and P. lecomtei showed partially compatible positive interaction on plates. The co-cultures respond positively to variations of temperature and inoculum interval, generating extracts responsible for higher hydrolysis yield when grown at 25 °C, and P. lecomtei is inoculated 24 h after T. reesei. The enzymatic extract production of co-cultures was also improved by modifying the components of the initial media and evaluating enzymatic activities, hydrolysis of sugarcane bagasse pretreated by autohydrolysis and ethanol production as a response. Five culture media were evaluated with variations in the composition of nutritional elements, minerals and substrates. The best extract showed a maximum cellulose hydrolysis efficiency of 68.7% compared with 44.8% of the initial medium. The ethanolic fermentation of hydrolysates obtained by co-culture extracts showed higher ethanol yields than monocultures. This work demonstrates the use of fungi co-cultures to produce enzymatic extracts composed of cellulolytic, hemicellulolytic, and ligninolytic enzymes complexes, which allow hydrolyzing pretreated lignocellulosic biomass with high efficiency, generating hydrolysates that are easier fermented by yeast
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