Navegando por Palavras-chave "Yeast"

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    Characterization of paracoccidioides brasiliensis by ft-ir spectroscopy and nanotechnology
    (Univ Brasilia, 2016) Ferreira, Isabelle; Ferreira-Strixino, Juliana; Castilho, Maiara L.; Campos, Claudia Barbosa Ladeira de [UNIFESP]; Tellez, Claudio; Raniero, Leandro
    Paracoccidioides brasiliensis, the etiological agent of paracoccidioidomycosis, is a dimorphic fungus existing as mycelia in the environment (or at 25 degrees C in vitro) and as yeast cells in the human host (or at 37 degrees C in vitro). Because mycological examination of lesions in patients frequently is unable to show the presence of the fungus and serological tests can misdiagnose the disease with other mycosis, the development of new approach's for molecular identification of P. brasiliensis spurges is needed. This study describes the use of a gold nanoprobe of a known gene sequence of P. brasiliensis as a molecular tool to identify P. brasiliensis by regular polymerase chain reaction (PCR) associated with a colorimetric methods. This approach is suitable for testing in remote areas because it does not require any further step than gene amplification, being safer and cheaper than electrophoresis methods. The proposed test showed a color change of the PCR reaction mixture from red to blue in negative samples, whereas the solution remains red in positive samples. We also performed a Fourier Transform Infrared (FT-IR) Spectroscopy analysis to characterize and compare the chemical composition between yeast and mycelia forms, which revealed biochemical differences between these two forms. The analysis of the spectra showed that differences were distributed in chemical bonds of proteins, lipids and carbohydrates. The most prominent difference between both forms was vibration modes related to 1,3-beta-glucan usually found in mycelia and 1,3-alpha-glucan found in yeasts and also chitin forms. In this work, we introduce FT-IR as a new method suitable to reveal overall differences that biochemically distinguish each form of P. brasiliensis that could be additionally used to discriminate biochemical differences among a single form under distinct environmental conditions. (C) 2015 Elsevier B.V. All rights reserved.
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    Degradação de resíduo de levedura empregado em biossorção por processos eletro-oxidativos avançados
    (Universidade Federal de São Paulo, 2017-10-06) Bargas, Maria Francisca Ribeiro de Aguiar [UNIFESP]; Rodrigues, Christiane de Arruda [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    The use of agroindustrial waste as adsorbents has been evaluated as an alternative treatment of textile effluents, mainly for color removal. However, solutions are required for the proper fate of the adsorbent after sorption of the organic compound. In this way, the Advanced Oxidative Processes (POA) appear as an alternative of clean destination of the solid residues containing organic compound. The objective of this work was to evaluate the efficiency in the treatment of the degradation of dry yeast biomass, biosorbent from the residue of the sugar and alcohol industry, after the sorption of methylene blue reactive dye by means of photo-Fenton and heterogeneous photocatalysis (photocatalysis and photoelectrocatalysis) using a TiO2 nanotubular oxide layer as catalyst. The study was carried out with three yeast biomasses, washed yeast biomass (WYB), in nature Yeast Biomass (YB) and yeast biomass after the sorption of the methylene blue reactive dye (SYB). Initially the BL was washed with distilled water to remove the soluble residue in order to quantify the reduction of mass and mineralization only of the solid fraction. The optimization studies of the best conditions of degradation and mineralization of the organic matter were obtained with the WYB. The optimization studies of the best conditions of degradation and mineralization of the organic matter were obtained with the WYB. In the photo-Fenton process, the optimized condition was 2,500 mg L-1 of H2O2 and 40 mg L-1 of Fe2+ and 100 mg of biomass mass, with sequential addition of H2O2 during the degradation process, at 15 min intervals, during 2 hours of treatment, with a percentage of mineralization around 45% and destruction of the degraded biomass (lysed). While in heterogeneous photocatalysis, although there is no evidence of cell lysis, the photocatalytic treatment showed to be more efficient in reducing the organic load of the WYB and YB compared to the treatment by photoelectrocatalysis, with a mass reduction percentage of around 46,5% after 4 hours of treatment. In both studies, an irradiation source with a mercury vapor lamp of 80 W was used. Then, the combination of the optimized processes, photo-Fenton followed by photocatalysis, was employed in the treatment of YB and SYB. After the degradation, YB presented a reduction of mass and mineralization around 85% and SYB around 60% of mass reduction and 50% of mineralization. The combination of the photo-Fenton process followed by the heterogeneous photocatalysis showed to be a clean destination of solid residues formed by yeast biomass with adsorbed dye.
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    Identificação e caracterização de leveduras produtoras de micosporinas: uma abordagem biotecnológica para novos bloqueadores de radiação UV-A e UV-B
    (Universidade Federal de São Paulo, 2023-06-27) Silva, Gabriel Martins da [UNIFESP]; Pascon, Renata Castiglioni [UNIFESP]; Medeiros, Lívia Soman de [UNIFESP]; http://lattes.cnpq.br/7404733691134037; http://lattes.cnpq.br/4203540318082044; http://lattes.cnpq.br/6738128314527827
    A radiação ultravioleta causa diversos efeitos nocivos aos organismos vivos, em especial na epiderme humana, onde as lesões podem culminar em câncer de pele. As alternativas existentes para evitar ou retardar esses impactos na pele, são os protetores solares sintéticos artificiais, os quais são tóxicos, pois têm potencial carcinogênico e neurotóxico em humanos. Além disso, são citotóxicos e acumulam em organismos de ecossistemas aquáticos. Biomoléculas produzidas por algas, cianobactérias e fungos, conhecidas como micosporinas e aminoácidos tipo micosporinas, são capazes de converter radiação ultravioleta em calor, logo, podem compor um protetor solar alternativo com baixa ou nenhuma toxicidade. O Laboratório de Interações Microbianas da Universidade Federal de São Paulo, tem se dedicado a colecionar leveduras que possuam a capacidade de realizar a biossíntese de micosporinas. Atualmente foram reunidos 4 isolados produtores de micosporinas Com isso, o objetivo deste trabalho foi caracterizar fenotipicamente estes isolados, e testar a capacidade de produzir micosporinas. Foram empregadas técnicas de microscopia ótica, diluição seriada, PCR, sequenciamento de Sanger e Ultra High Performance Liquid Chromatography – High Resolution Mass Spectrometry. Foi possível fazer uma análise fenotípica da micromorfologia, testar as melhores temperaturas de crescimento, confirmar a identificação dos isolados pelo sequenciamento dos genes que codificam as subunidades maior e menor do ribossomo e região do espaçador interno transcrito. Também confirmamos o baixo potencial patogênico dos isolados, resistência deles ao estresse osmótico e houve a confirmação da produção de micosporinas em todos dos isolados investigados. Portanto, os isolados testados no trabalho apresentam potencial biotecnológico para a produção de um protetor solar sintético natural seguro para os humanos e para o meio ambiente.
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    Impacto da deleção de GPP2 sobre o processo de autofagia em Cryptococcus neoformans
    (Universidade Federal de São Paulo, 2021-09-30) Padilla, Adrian Alvarez Padilla [UNIFESP]; Vallim, Marcelo Afonso [UNIFESP]; http://lattes.cnpq.br/4039129182586680; http://lattes.cnpq.br/5182785443286188
    A criptococose é uma micose de caráter sistêmico de grande importância clínica. A doença é causada, sobretudo, pelas espécies dos complexos Cryptococcus neoformans e Cryptococcus gattii, esses fungos patogênicos, onipresentes e oportunistas causam infecção pulmonar, cutânea, renal, esplenomegalia e, mais importante dada a letariedade, a meningoencefalite. A criptococcose acomete, principalmente, pacientes com sistema imunológico debilitado. Durante a infecção, a levedura precisa se adaptar às condições desfavoráveis no hospedeiro como a alta temperatura (37° C) e a disponibilidade de nutrientes. O tratamento dessa micose compreende o uso prolongado de antifúngicos que, em sua maioria, são tóxicos para o paciente e o uso constante desses medicamentos induz o surgimento de cepas resistentes. Dessa forma, novas terapias antifúngicas são necessárias para aumentar as opções de tratamento. A autofagia atua como um sistema de degradação e reciclagem intracelular de macromoléculas e organelas que garante a homeostasia e a sobrevivência da célula diante de diferentes fatores de estresse. Análises de transcriptoma RNAseq em meio rico (YPD) em C. neoformans mostram que a deleção do gene GPP2 reprime e induz alguns genes chaves da autofagia tais como: ATG1, ATG2, ATG4, VPS15, ATG15, VPS30 e PEP4. Os nossos dados de qPCR validaram os resultados das análises de RNAseq. Trabalhos anteriores do nosso grupo mostraram que no mutante gpp2Δ ocorre a interrupção de várias vias biossintéticas e captação de aminoácidos que resulta na queda da viabilidade celular, incapacidade de lidar com vários tipos de estresses, redução da expressão de fatores de virulência, (melanina, fosfolipase e urease) e atenuação de virulência em Galleria mellonella, indicando que a biossíntese e absorção de aminoácidos sulfurosos é uma característica importante para a sobrevivência do patógeno in vivo e in vitro. Em Saccharomyces cerevisiae, o Gpp2 é induzido em resposta ao estresse hiperosmótico e oxidativo. Neste trabalho mostramos que em C. neoformans, Gpp2 é necessário para responder, principalmente, ao estresse osmótico, e que a via da autofagia encontra-se reprimida na presença do aminoácido metionina tanto na linhagem selvagem como no mutante gpp2Δ. Nossos dados em conjunto com os trabalhos anteriores, reportados pelo nosso grupo de pesquisa, sugerem que Gpp2 é um fator importante para a adaptação geral do patógeno a vários estresses e talvez possa ser um alvo interessante para uso terapêutico.
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    Prospecção de leveduras de compostagem tolerantes à disruptores endócrinos inorgânicos
    (Universidade Federal de São Paulo, 2013-11-28) Trama, Bianca [UNIFESP]; Vallim, Marcelo Afonso [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    The input of inorganic endocrine disruptors of anthropogenic origin in the environment has been pointed out by scientists, nongovernmental agencies and government as an imminent public health problem. Among the innovative solutions for contaminated water treatment is the use of biological materials like living or dead microorganisms as biosorbent. Yeasts exhibit the ability to adapt to extreme condition such as temperature, pH and levels of organic and inorganic contaminants that make them a potential material to be used as biosorbent for contaminated environment application. The aim of this project was to access the tolerance of several yeast strains isolated from the São Paulo Zoo composting unit to the presence of inorganic endocrine disruptors such as Pb2+ and Mn2+. Four yeast strains (BY4742, PE-2, CAT-1 and BG-1) were employed as source of comparison for tolarence and sorption ability. As a result we found one yeast with high potencial for Pb biosorption and nine isolates with high tolerance to Mn which can be utilized in sorption process.
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    Sialoglycoproteins in Morphological Distinct Stages of Mucor polymorphosporus and their Influence on Phagocytosis by Human Blood Phagocytes
    (Springer, 2013-10-01) Almeida, Catia Amancio; Campos-Takaki, Galba Maria de; Portela, Maristela Barbosa; Travassos, Luiz R. [UNIFESP]; Alviano, Celuta Sales; Alviano, Daniela Sales; Universidade Federal do Rio de Janeiro (UFRJ); Univ Catolica Pernambuco; Universidade Federal Fluminense (UFF); Universidade Federal de São Paulo (UNIFESP)
    The possible role of sialic acids in host cells-fungi interaction and their association with glycoproteins were evaluated using a clinical isolate of the dimorphic fungus Mucor polymorphosporus. Lectin-binding assays with spores and yeast cells denoted the presence of surface sialoglycoconjugates containing 2,3- and 2,6-linked sialylglycosyl groups. Western blotting with peroxidase-labeled Limulus polyphemus agglutinin revealed the occurrence of different sialoglycoprotein types in both cell lysates and cell wall protein extracts of mycelia, spores, and yeasts of M. polymorphosporus. Sialic acids contributed to the surface negative charge of spores and yeast forms as evaluated by adherence to a cationic substrate. Sialidase-treated spores were less resistant to phagocytosis by human neutrophils and monocytes from healthy individuals than control (untreated) fungal suspensions. the results suggest that sialic acids are terminal units of various glycoproteins of M. polymorphosporus, contributing to negative charge of yeasts and spore cells and protecting infectious propagules from destruction by host cells.
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    Wine Aroma Improvement Using a beta-Glucosidase Preparation from Aureobasidium pullulans
    (Humana Press Inc, 2013-01-01) Baffi, Milla Alves; Tobal, Thaise; Ghilardi Lago, Joao Henrique [UNIFESP]; Boscolo, Mauricio; Gomes, Eleni; Da-Silva, Roberto; Universidade Federal de Uberlândia (UFU); São Paulo State Univ UNESP; Universidade Federal de São Paulo (UNIFESP)
    Microbial beta-glucosidases have been used for the enhancement of wine aroma. Nevertheless, few enzymes are active in the conditions of winemaking. in this work, the production of a beta-glucosidase by an Aureobasidium pullulans strain (Ap-beta-gl) isolated from grape ecosystems was evaluated. the maximum enzymatic synthesis using submerged fermentation was after 96 h of growth in complex media containing 20 g/L of cellobiose as the sole carbon source. the crude enzyme (Ap-beta-gl) showed optimal pH at 5.5 and two peaks of optimum temperature (at 45 and 70 A degrees C). It showed a wide range of pH stability, stability at low temperatures, and tolerance to ethanol, showing suitable characteristics for winemaking conditions. the hydrolysis of glycosidic terpenes by Ap-beta-gl was studied, and its ability to efficiently release free terpenols was demonstrated by gas chromatography/mass spectrometry. the enzymatic treatment notably increased the amount of monoterpenes, showing good prospects for its potential application for the development of aroma in wines.