The effect of several carbon sources on the production of mycelial-bound β-glucosidase by Humicola grisea var. thermoidea in submerged fermentation was investigated. Maximum production occurred when ...cellulose was present in the culture medium, but higher specific activities were achieved with cellobiose or sugarcane bagasse. Xylose or glucose (1%) in the reaction medium stimulated β-glucosidase activity by about 2-fold in crude extracts from mycelia grown in sugarcane bagasse. The enzyme was purified by ammonium sulfate precipitation, followed by Sephadex G-200 and DEAE-cellulose chromatography, showing a single band in PAGE and SDS-PAGE. The β-glucosidase had a carbohydrate content of 43% and showed apparent molecular masses of 57 and 60 kDa, as estimated by SDS-PAGE and gel filtration, respectively. The optimal pH and temperature were 6.0 and 50℃, respectively. The purified enzyme was thermostable up to 60 min in water at 55℃ and showed half-lives of 7 and 14 min when incubated in the absence or presence of 50 mM glucose, respectively, at 60℃. The enzyme hydrolyzed p-nitrophenyl-β-D-glucopyranoside, p-nitrophenyl-β-D-galactopyranoside, p-nitrophenyl-β-D-fucopyranoside, p-nitrophenyl-β-D-xylopyranoside, o-nitrophenyl-beta-β-galactopyranoside, lactose, and cellobiose. The best synthetic and natural substrates were p-nitrophenyl-β-D-fucopyranoside and cellobiose, respectively. Purified enzyme activity was stimulated up to 2-fold by glucose or xylose at concentrations from 25 to 200 mM. The addition of purified or crude β-glucosidase to a reaction medium containing Trichoderma reesei cellulases increased the saccharification of sugarcane bagasse by about 50%. These findings suggest that H. grisea var. thermoidea β-glucosidase has a potential for biotechnological applications in the bioconversion of lignocellulosic materials.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A fitorremediação é uma alternativa na descontaminação do meio ambiente, no qual utilizam as plantas capazes de absorver os íons contaminantes. Deste modo, a pesquisa científica tem como objetivo de ...verificar se o milho consegue fitoextrair, acumular, hiperacumular e tolerar os metais tóxicos na biomassa vegetal em solos contaminados antropicamente. O delineamento experimental foi inteiramente casualizado, composto por quatro tratamentos com quatro repetições, totalizando dezesseis parcelas para cada contaminante. A aplicação dos metais e do EDTA foram realizados na forma de solução, contaminando o solo após 46 dias da maturação do milho em vasos. As concentrações foram acima dos valores de intervenção da CETESB. As análises do solo e dos tecidos vegetais foram realizadas pelo Espectrômetro de Absorção Atômica, no qual resultaram em concentrações significativas. Os resultados da Analise de Variância e Teste de Tukey post-hoc, sofreram uma redução da biomassa seca e um aumento da quantidade acumulada. O milho foi tolerante a maior dose de chumbo, porém foi intolerante as maiores doses de cádmio e cromo. Deste modo, os resultados indicaram que o milho fitoextraiu os contaminantes eficientemente, porém não pode ser utilizado como fitorremediadora em locais contaminados pois provocam a intoxicação alimentar para os seres vivos, uma vez que o milho é utilizado no Brasil e no mundo para alimentação animal e para indústria alimentícia de altas qualidades nutricionais e energéticas.
A mycelial β-glucosidase from the thermophilic mold
Humicola insolens was purified and biochemically characterized. The enzyme showed carbohydrate content of 21% and apparent molecular mass of 94
...kDa, as estimated by gel filtration. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis showed a single polypeptide band of 55
kDa, suggesting that the native enzyme was a homodimer. Mass spectrometry analysis showed amino acid sequence similarity with a β-glucosidase from
Humicola grisea var.
thermoidea, with about 22% coverage. Optima of temperature and pH were 60
°C and 6.0–6.5, respectively. The enzyme was stable up to 1
h at 50
°C and showed a half-life of approximately 44
min at 55
°C. The β-glucosidase hydrolyzed cellobiose, lactose, p-nitrophenyl-β-
d-glucopyranoside, p-nitrophenyl-β-
d-fucopyranoside, p-nitrophenyl-β-
d-xylopyranoside, p-nitrophenyl-β-
d-galactopyranoside, o-nitrophenyl-β-
d-galactopyranoside, and salicin. Kinetic studies showed that p-nitrophenyl-β-
d-fucopyranoside and cellobiose were the best enzyme substrates. Enzyme activity was stimulated by glucose or xylose at concentrations up to 400
mM, with maximal stimulatory effect (about 2-fold) around 40
mM. The high catalytic efficiency for the natural substrate, good thermal stability, strong stimulation by glucose or xylose, and tolerance to elevated concentrations of these monosaccharides qualify this enzyme for application in the hydrolysis of cellulosic materials.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The phytoremediation is an alternative in the decontamination of the environment, in which plants capable of absorbing contaminating ions are used. Thereby, the scientific research aims to verify if ...the corn can phytoextract, accumulate, hyperaccumulate and tolerate toxic metals in the plant biomass in anthropically contaminated soils. The experimental design was completely randomized, consisting of four treatments with four replications, totaling sixteen portions for each contaminant. The application of metals and EDTA were carried out in the form of a solution, contaminating the soil 46 days after maize maturation in pots. The concentrations were above the intervention values of CETESB. Soil and plant tissues analyzes were performed by the Atomic Absorption Spectrometer, which resulted in significant concentrations. The results of the Analysis of Variance and post-hoc Tukey's Test, suffered a reduction in dry biomass and an increase in the accumulated amount. Corn was tolerant to the highest dose of lead, but it was intolerant to the highest doses of cadmium and chromium. Thus, the results indicated that the maize phytoextracted contaminants efficiently, but it cannot be used as a phytoremediator in contaminated sites because they cause food poisoning for the living beings, once corn is used in Brazil and worldwide for animal feed and for the food industry of high nutritional and energy qualities.
A reunião de revista "Telemedicina Baseada em Evidência - Cirurgia do Trauma e Emergência" (TBE-CiTE) realizou uma revisão crítica da literatura e selecionou três artigos recentes sobre o uso de ...corticoide para a profilaxia da síndrome de embolia gordurosa. O foco desta revisão foi a indicação ou não do uso de corticoide nos pacientes admitidos na unidade de terapia intensiva (UTI) com risco de desenvolverem embolia gordurosa pós traumática. O primeiro artigo foi um estudo prospectivo com o objetivo de estabelecer fatores preditivos confiáveis, precoces e úteis associados ao aparecimento da síndrome da embolia gordurosa (SEG) em pacientes traumatizados. O segundo artigo foi uma revisão de literatura sobre o papel do corticoide como medida profilática à síndrome de embolia gordurosa. O último artigo foi uma meta-análise sobre a capacidade do corticoide em reduzir o risco de síndrome da embolia gordurosa nos pacientes com fraturas de ossos longos. As principais conclusões e recomendações foram que pacientes traumatizados devem ser monitorizados na UTI com oximetria de pulso e medida do lactato já que estes fatores podem predizer o aparecimento de SEG e que não existe evidência suficiente para recomendar o uso de corticoide para a profilaxia desta síndrome.
A mycelial b-glucosidase from the thermophilic mold Humicola insolens was purified and biochemically characterized. The enzyme showed carbohydrate content of 21% and apparent molecular mass of 94 ...kDa, as estimated by gel filtration. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis showed a single polypeptide band of 55 kDa, suggesting that the native enzyme was a homodimer. Mass spectrometry analysis showed amino acid sequence similarity with a b-glucosidase from Humicola grisea var. thermoidea, with about 22% coverage. Optima of temperature and pH were 60 C and 6.0-6.5, respectively. The enzyme was stable up to 1 h at 50 C and showed a half-life of approximately 44 min at 55 C. The b-glucosidase hydrolyzed cellobiose, lactose, p-nitrophenyl-b-d-glucopyranoside, p-nitrophenyl-b-d-fucopyranoside, p-nitrophenyl-b-d-xylopyranoside, p-nitrophenyl-b-d-galactopyranoside, o-nitrophenyl-b-d-galactopyranoside, and salicin. Kinetic studies showed that p-nitrophenyl-b-d-fucopyranoside and cellobiose were the best enzyme substrates. Enzyme activity was stimulated by glucose or xylose at concentrations up to 400 mM, with maximal stimulatory effect (about 2-fold) around 40 mM. The high catalytic efficiency for the natural substrate, good thermal stability, strong stimulation by glucose or xylose, and tolerance to elevated concentrations of these monosaccharides qualify this enzyme for application in the hydrolysis of cellulosic materials.
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Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The effect of several carbon sources on the production of mycelial-bound β-glucosidase by Humicola grisea var. thermoidea in submerged fermentation was investigated. Maximum production occurred when ...cellulose was present in the culture medium, but higher specific activities were achieved with cellobiose or sugarcane bagasse. Xylose or glucose (1%) in the reaction medium stimulated β-glucosidase activity by about 2-fold in crude extracts from mycelia grown in sugarcane bagasse. The enzyme was purified by ammonium sulfate precipitation, followed by Sephadex G-200 and DEAE-cellulose chromatography, showing a single band in PAGE and SDS-PAGE. The β-glucosidase had a carbohydrate content of 43% and showed apparent molecular masses of 57 and 60 kDa, as estimated by SDS-PAGE and gel filtration, respectively. The optimal pH and temperature were 6.0 and 50°C, respectively. The purified enzyme was thermostable up to 60 min in water at 55°C and showed half-lives of 7 and 14 min when incubated in the absence or presence of 50 mM glucose, respectively, at 60°C. The enzyme hydrolyzed p-nitrophenyl-β-D-glucopyranoside, p-nitrophenyl-β-Dgalactopyranoside, p-nitrophenyl-β-D-fucopyranoside, p-nitrophenyl-β-D-xylopyranoside, o-nitrophenyl-β-Dgalactopyranoside, lactose, and cellobiose. The best synthetic and natural substrates were p-nitrophenyl-β-Dfucopyranoside and cellobiose, respectively. Purified enzyme activity was stimulated up to 2-fold by glucose or xylose at concentrations from 25 to 200 mM. The addition of purified or crude β-glucosidase to a reaction medium containing Trichoderma reesei cellulases increased the saccharification of sugarcane bagasse by about 50%. These findings suggest that H. grisea var. thermoidea β-glucosidase has a potential for biotechnological applications in the bioconversion of lignocellulosic materials.PUBLICATION ABSTRACT
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A reunião de revista "Telemedicina Baseada em Evidência - Cirurgia do Trauma e Emergência" (TBE-CiTE) realizou uma revisão crítica da literatura e selecionou três artigos recentes sobre o uso de ...corticoide para a profilaxia da síndrome de embolia gordurosa. O foco desta revisão foi a indicação ou não do uso de corticoide nos pacientes admitidos na unidade de terapia intensiva (UTI) com risco de desenvolverem embolia gordurosa pós traumática. O primeiro artigo foi um estudo prospectivo com o objetivo de estabelecer fatores preditivos confiáveis, precoces e úteis associados ao aparecimento da síndrome da embolia gordurosa (SEG) em pacientes traumatizados. O segundo artigo foi uma revisão de literatura sobre o papel do corticoide como medida profilática à síndrome de embolia gordurosa. O último artigo foi uma meta-análise sobre a capacidade do corticoide em reduzir o risco de síndrome da embolia gordurosa nos pacientes com fraturas de ossos longos. As principais conclusões e recomendações foram que pacientes traumatizados devem ser monitorizados na UTI com oximetria de pulso e medida do lactato já que estes fatores podem predizer o aparecimento de SEG e que não existe evidência suficiente para recomendar o uso de corticoide para a profilaxia desta síndrome.
The "Evidence-based Telemedicine - Trauma & Acute Care Surgery" (EBT-TACS) Journal Club conducted a critical review of the literature and selected three recent studies on the use of corticosteroids for the prophylaxis of fat embolism syndrome. The review focused on the potential role of corticosteroids administration to patients admitted to the intensive care unit (ICU) at risk of developing post-traumatic fat embolism. The first study was prospective and aimed at identifying reliable predictors, which occurred early and were associated with the onset of fat embolism syndrome in trauma patients. The second manuscript was a literature review of the role of corticosteroids as a prophylactic measure for fat embolism syndrome (FES). The last manuscript was a meta-analysis on the potential for corticosteroids to prophylactically reduce the risk of fat embolism syndrome in patients with long bone fractures. The main conclusions and recommendations reached were that traumatized patients should be monitored with non-invasive pulse oximetry and lactate levels since these factors may predict the development of FES, and that there is not enough evidence to recommend the use of steroids for the prophylaxis of this syndrome.
RESUMO As fosfatases alcalinas sao enzimas que participam da atividade catalitica na hidrolise de ésteres fosfóricos. Nesta Dissertação, investigou-se a sua adsorção em monocamadas de Langmuir e ...também em filmes do tipo Langmuir-Blodgett (LB) de fosfolipídios em diferentes temperaturas. Esses sistemas são considerados como modelos para membranas biológicas. O efeito de um dissacarídeo (trealose), bem como as impurezas contidas na amostra do açúcar, foi testado na subfase que suporta a monocamada,. Constatou-se que a trealose nao purificada altera a isoterma superficial de monocamadas do sal de sódio do acido dimiristoilglicerofosfatidico, DMPA, e atua como um bom agente de ligação entre camadas sucessivas do fosfolipídio para a obtenção de filmes LB. Já para trealose purificada nao se observaram esses efeitos. A caracterização das impurezas foi realizada por espectroscopia na região do infravermelho e por absorção atômica, detectando-se a presença de moléculas anfifílicas e de íons metálicos (Na+, K+, Ca2+, Mg2+), respectivamente. Dois tipos de fosfatases alcalinas foram usadas: uma purificada de placa óssea de ratos por extração com tensoativo nâo-iônico, chamada de DSAP e outra purificada de conídia de Neurospora crassa, denominada CNCAP. As interações com o fosfolipídio foram estudas por meio das mudanças nas curvas -A e a adsorção em filmes LB de DMPA/Zn2+ e DMPA/trealose, por meio da técnica de microbalança a cristal de quartzo (QCM). A presença das enzimas nos filmes foi também comprovada pela detecção de suas atividades catalíticas na hidrolise do PNPP (p-nitrofenilfosfato). Para a DSAP, a melhor atividade foi obtida quando a imobilização da proteína ocorreu a baixa temperatura (10º C).
ABSTRACT Alkaline phosphatases (AP) are unspecific enzymes that hydrolyze phosphate esthers. In this Dissertation we have studied the adsorption of two forms of AP in phospholipid Langmuir monolayers and Langmuir-Blodgett films, considered as biomembrane models, at different temperatures. Further, the effect of the presence of a disaccharide, trehalose, as well as some impurities present in its commercial form, in the subphase of the monolayers was tested. We concluded that the use of trehalose without further purification alters the surface pressure-area (Pi-A) curves of the monolayers. In addition, it acts as a good linking agent between successive layers in the Langmuir-Blodgett films of the sodium salt of 1,2-dimirystoyl-sn-glicero-3-phosphate acid, DMPA. In the presence of purified trehalose instead, these effects were not observed. No difference was noticed in the Pi-A curves of DMPA for trehalose concentrations between 10-3 mmol L-1 to 0.1 mmol L-1. The characterization of the impurities by atomic absorption and infrared spectroscopy reveal the presence of amphiphilic compounds as well as electrolytes such as: sodium, magnesium, calcium and potassium Two forms of AP were used: one purified from rat osseous plates using detergent solubilization, named DSAP, and the other from Neurospora crassa conidia, CNCAP. Enzyme interaction with phospholipids was followed by changes in Pi-A curves, and their adsorption on DMPA/Zn2+ or DMPA/trehalose LB films using the quartz crystal microbalance technique, QCM. Their presence within the films was also monitored by catalytic activity assays, using PNPP (p-nitrophenylphosphate) as hydrolysis substrate. For DSAP, the highest enzymatic activity was observed when the immobilization was carried out at low temperature (10o C).
The "Evidence-based Telemedicine - Trauma & Acute Care Surgery" (EBT-TACS) Journal Club conducted a critical review of the literature and selected three recent studies on the use of corticosteroids ...for the prophylaxis of fat embolism syndrome. The review focused on the potential role of corticosteroids administration to patients admitted to the intensive care unit (ICU) at risk of developing post-traumatic fat embolism. The first study was prospective and aimed at identifying reliable predictors, which occurred early and were associated with the onset of fat embolism syndrome in trauma patients. The second manuscript was a literature review of the role of corticosteroids as a prophylactic measure for fat embolism syndrome (FES). The last manuscript was a meta-analysis on the potential for corticosteroids to prophylactically reduce the risk of fat embolism syndrome in patients with long bone fractures. The main conclusions and recommendations reached were that traumatized patients should be monitored with non-invasive pulse oximetry and lactate levels since these factors may predict the development of FES, and that there is not enough evidence to recommend the use of steroids for the prophylaxis of this syndrome.
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