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This study investigated the impact of a support matrix and active group on the support to the nutritional properties of orange juice after juice clarification. Pectinase was immobilized on chitosan and aminated silica supports, activated with genipin or glutaraldehyde, and applied for juice clarification. The effects on various juice properties, including reducing sugars, total soluble solids, vitamin C, and phenolic compounds, juice color, and pH, were evaluated. The results revealed that the immobilization on chitosan activated using genipin resulted in the highest biocatalyst activity (1211.21 U·g-1). The juice treatments using the biocatalysts led to turbidity reduction in the juice (up to 90%), with the highest reductions observed in treatments involving immobilized enzyme on chitosan. Importantly, the enzymatic treatments preserved the natural sugar content, total soluble solids, and pH of the juice. Color differences between treated and raw juice samples were especially relevant for those treated using enzymes, with significant differences in L* and b*, showing loss of yellow vivid color. Analysis of phenolic compounds and vitamin C showed no significant alterations after the enzymatic treatment of the raw juice. According to our results, the clarification of orange juice using immobilized enzymes can be a compromise in turbidity reduction and color reduction to maintain juice quality.
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Antecedentes: La Diafanización dental es una técnica que permite transparentar los dientes haciendo visible la anatomía interna de los conductos radiculares ofreciendo una herramienta pedagógica económica y confiable; sin embargo, la literatura no reporta protocolos estandarizados para obtener una diafanización dental predecible. Objetivo: Obtener un protocolo estandarizado para diafanización dental, como modelo educativo, a partir de la revisión de la literatura y la realización de un estudio piloto. Materiales y Métodos: Se realizó una búsqueda sistemática en las bases de datos Scopus y Medline con los términos Mesh "root canal", "diaphonization", "clearing", "morphology" anatomy", y se estructuró una tabla de extracción con las variables más representativas para establecer las 3 fases de la Diafanización, a. Descalcificación, se evaluó Ácido Nítrico 5% (HNO3), Ácido Fórmico 10% (CH2O2) y EDTA 10%, b. Deshidratación, se empleó Alcoholes etílicos ascendentes, c. Clarificación, se evaluó Metil Salicilato y Aceite de Inmersión Sintético. Se seleccionaron 54 dientes, 36 sin endodoncia, y 18 con endodoncia, y se distribuyeron en dos grupos: Grupo A. Dientes sin endodoncia, Grupo B. Dientes con endodoncia, constituidos por 18 subgrupos que estaban definidos de acuerdo al tipo de descalcificante, momento de aplicación medio de contraste y medio de Clarificación. Resultados: El Ácido Nítrico al 5% pese a que fue el más corrosivo, permitió el mayor flujo y accesibilidad para el medio de contraste (Tinta China) en especímenes sin endodoncia. De igual manera, el Ácido Fórmico al 10%, preservó la estructura de los dientes tratados endodónticamente. El Metil Salicilato como clarificante, brindó mejores resultados visuales alcanzando una mayor transparencia. Conclusiones: El desarrollo de un estudio piloto para estandarizar técnicas de diafanización en odontología, permite la estructuración de un protocolo educativo que posibilita conocer la gran variabilidad anatómica de los dientes y la comprensión y análisis de los dientes que han si do tratados endodóncicamente, aportando una herramienta pedagógica para la comprensión de la anatomía radicular. El uso de Ácido Fórmico al 10%, en dientes con tratamiento de endodoncia y de Ácido Nítrico 5% en dientes sin endodoncia, c on una transparencia alcanzada por el uso del Metil Salicilato, muestran los mejores resultados visuales en anatomía y obturación endodóntica.
Background: Dental diaphonization is a technique that allows the teeth to be made transparent, making the internal anatomy of the root canals visible, offering an economical and reliable pedagogical tool; however,the literature does not report standardized protocols to obtain a predictable dental clearance. Aim: obtain a standardized protocol for dental diaphonization as an educative model from the review of the literature and the realization of a pilot study. Materials and methods: A systematic search was made on databases Scopus and Medline, with the Mesh terms "root canal", "diaphonization", "clearing", "morphology" and, "anatomy", and an extraction table was structured wit h the most representative variables to establish the three diaphanization phases, a. Decalcification, 5% Nitric Acid, 10% Formic Acid (TBD-2) and 10% EDTA were evaluated, b. Dehydration, ascending Ethyl Alcohols were used, c. Clarification, Methyl Salicylate, a nd Immersion synthetic oil were evaluated. 54 teeth were selected, 36 without root canal treatment and 18 with root canal treatment, then they were distributed into two groups: Group A, Teeth without root canal treatment, and Group B, Teeth with root canal treatment. Each group was constituted of 18 subgroups defined in order of the decalcification agent type, moment of the contrast medium application, and clarification agent type. Results: Even though 5% Nitric Acid was the most corrosive agent, it allowed a better flow and accessibility for the contrast medium (Chinese ink) in teeth without root canal treatment. Likewise, 10% Formic Acid preserved the structure of the endodontic tooth. As a clarification agent, the Methyl Salicylate showed better visual results, achieving greater transparency. Conclusion: The development of a pilot study aimed to standardize diaphonization techniques in dentistry allows the structuring of educative protocols that permit knowing the great tooth anatomic variability and the comprehension as well as the analysis of the root canal treated teeth, contributing to a pedagogic tool for the root anatomy awareness. Using 10% Formic Acid on root canal-treated teeth and 5% Nitric Acid on root canal not treated teeth, with transparency achieved by using Methyl Salicylate, showed better visual results on anatomy and endodontic filling
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The recovery of valuable compounds like phenolic compounds and sugars from grape marc extracts implies different steps, including clarification. In this study, a response surface methodology (RSM) was used as a statistical tool to study the effects of operating conditions such as transmembrane pressure (TMP), temperature and feed flow rate on the performance of a microfiltration (MF) monotubular ceramic membrane with a pore size of 0.14 µm in the clarification of grape marc extract from the Carménère variety, as well to optimize the process conditions by implementing the Box-Behnken statistical design. The desirability function approach was applied to analyze the regression model equations in order to maximize the permeate flux and concentration of malvidin-3-O-glucoside, glucose and fructose in the clarified extract. The optimal operating conditions were found to be 1 bar, 29.01 °C and 5.64 L/min. Under these conditions, the permeate flux and concentration of malvidin-3-O-glucoside, glucose and fructose resulted in 65.78 L/m2h, 43.73 mg/L, 305.89 mg/L, and 274.85 mg/L, respectively.
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This study evaluates both the occurrence and removal of 24 compounds, including drugs and endocrine disruptors, in 8 water treatment plants (WTP) located in the metropolitan region of Belo Horizonte (Minas Gerais State, Brazil). The compounds 4-nonylphenol, 4-octylphenol, 17α-ethinylestradiol, 17ß-estradiol, acyclovir, bisphenol A, bezafibrate, caffeine, dexamethasone, diclofenac sodium, diltiazem, estrone, estriol, gemfibrozil, ibuprofen, linezolid, loratadine, losartan, metformin, naproxen, paracetamol, promethazine, propranolol and sulfamethoxazole were monitored at 3 sampling points (raw water, filtered water, treated water) over 10 or 12 collection campaigns for each WTP. The results showed that bisphenol A occurred at higher concentrations during the dry period with a maximum concentration of 3257.1 ng L-1, while the compounds 4-nonylphenol and losartan exhibited higher concentrations in the rainy period with maximum concentrations of 8577.2 ng L-1 and 705.8 ng L-1, respectively. Regarding the removal of compounds in the monitored WTPs, the clarification step demonstrated better removals for 4-nonylphenol, bisphenol-A, paracetamol, and sulfamethoxazole, whereas the disinfection step mainly removed the compounds 4-octylphenol and estrone. Margin of exposure (ME) assessment results indicated that only dexamethasone, ethinyl estradiol, diclofenac, estradiol, and estrone were classified as imminent risk or alert considering the 95th percentile concentration found in the samples of treated water.
Assuntos
Disruptores Endócrinos , Poluentes Químicos da Água , Acetaminofen , Brasil , Dexametasona , Disruptores Endócrinos/análise , Monitoramento Ambiental , Estradiol/análise , Estrona , Etinilestradiol/análise , Losartan , Sulfametoxazol , Poluentes Químicos da Água/análise , Abastecimento de ÁguaRESUMO
The misuse of antibiotics in the cattle sector can lead to milk contamination, with concomitant effects on the dairy industry and human health. Biosensors can be applied in this field; however, the influence of the milk matrix on their activity has been poorly studied in light of the preanalytical process. Herein, aptamer-conjugated gold nanoparticles (nanoaptasensors) were investigated for the colorimetric detection in raw milk of four antibiotics used in cattle. The effect of milk components on the colorimetric response of the nanoaptasensors was analyzed by following the selective aggregation of the nanoparticles, using the absorption ratio A520/A720. A preanalytical strategy was developed to apply the nanoaptasensors to antibiotic-contaminated raw milk samples, which involves a clarification step with Carrez reagents followed by the removal of cations through dilution, chelation (EDTA) or precipitation (NaHCO3). The colorimetric signals were detected in spiked samples at concentrations of antibiotics as low as 0.25-fold the maximum residue limits (MRLs) for kanamycin (37.5 µg/L), oxytetracycline (25 µg/L), sulfadimethoxine (6.25 µg/L) and ampicillin (1 µg/L), according to European and Chilean legislation. Overall, we conclude that this methodology holds potential for the semiquantitative analysis of antibiotic residues in raw milk obtained directly from dairy farms.
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Aptâmeros de Nucleotídeos , Nanopartículas Metálicas , Animais , Antibacterianos/análise , Bovinos , Colorimetria , Ouro , Limite de Detecção , Leite/químicaRESUMO
In this study, fresh orange prickly pear juice (Opuntia spp.) was clarified by a cross-flow microfiltration (MF) process on a laboratory scale. The viability of the process-in terms of productivity (permeate flux of 77.80 L/h) and the rejection of selected membranes towards specific compounds-was analyzed. The quality of the clarified juice was also analyzed for total antioxidants (TEAC), betalains content (mg/100 g wet base), turbidity (NTU) and colorimetry parameters (L, a*, b*, Croma and H). The MF process permitted an excellent level of clarification, reducing the suspended solids and turbidity of the fresh juice. In the clarified juice, a decrease in total antioxidants (2.03 TEAC) and betalains content (4.54 mg/100 g wet basis) was observed as compared to the fresh juice. Furthermore, there were significant changes in color properties due to the effects of the L, a*, b*, C and h° values after removal of turbidity of the juice. The turbidity also decreased (from 164.33 to 0.37 NTU).
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Muchos conceptos relativos al tema de la sexualidad contemporánea son controversiales y frecuentemente mal conocidos por los mismos especialistas en salud mental. Inmersos en vertiginosos cambios culturales, todos sufrimos el peso de prejuicios sociales y sesgos subjetivos que condicionan opiniones y conductas, incluso bajo apariencias profesionales y científicas. Por ello, a fin de esclarecer la información respecto de esas nociones e informar ciertos datos útiles a una mejor reflexión de los tópicos de este Dossier se presenta a continuación una breve selección de textos que pueden echar luz sobre una mejor comprensión de los mismos.
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The influence of membrane pore size on the permeate flux, fouling mechanism, and rejection of soluble and suspended solids, as well as of phenolics and anthocyanins, in the clarification of grape marc extract by microfiltration (MF) was studied. MF was operated by using three monotubular ceramic membranes with a pore size of 0.14, 0.2, and 0.8 µm, respectively, according to a batch concentration configuration in selected operating conditions (2.25 bar as operating pressure, 4.93 L/min as feed flow rate, and 25 °C as operating temperature). No significant differences in the permeate flux values were appreciated despite the difference in pore size. The mathematical analyses of the flux behavior revealed that intermediate pore blocking is the predominant mechanism for 0.14 and 0.2 µm membranes, whereas complete pore blocking prevails for the 0.8 µm membrane. Differences in the fouling mechanism were associated with differences in the total phenols rejection: the highest rejection was observed for the 0.8 µm membrane followed by 0.2 and 0.14 µm membranes. All selected membranes showed low rejection of sugars, with values lower than 10%, and no retention towards anthocyanins. All the clarified extracts showed a turbidity lower than 4.87 NTU. Based on the experimental results, the 0.14 µm membrane appeared as the best option for the clarification of grape marc extract.
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Magnetic-chitosan particles were prepared following three different protocols enabling the preparation of particles with different sizes - nano (Nano-CMag, Micro (Micro-CMag) and Macro (Macro-CMag) - and used for pectinase immobilization and clarification of grape, apple and orange juices. The particle size had a great effect in the kinetic parameters, Nano-CMag biocatalyst presented the highest Vmax value (78.95â¯mg. min-1), followed by Micro-CMag and Macro-CMag, with Vmax of 57.20â¯mg.min-1 and 46.03â¯mg.min-1, respectively. However, the highest thermal stability was achieved using Macro-CMag, that was 8 and 3-times more stable than Nano-CMag and Micro-CMag biocatalysts, respectively. Pectinase immobilized on Macro-CMag kept 85% of its initial activity after 25 batch cycles in orange juice clarification. These results suggested that the chitosan magnetic biocatalysts presented great potential application as clarifying catalysts for the fruit juice industry and the great importance of the chitosan particles preparation on the final biocatalyst properties.
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AIMS: The aim of this work was to characterize and apply a polygalacturonase of Penicillium janthinellum new strain VI2R3M. METHODS AND RESULTS: The polygalacturonase obtained from P. janthinellum VI2R3M was incubated in cultures of passion fruit peel and was partially purified by ion-exchange chromatography and gel filtration. The enzyme showed a relative molecular mass of 102·0 kDa, maximum activity at pH 5·0, temperature of 50°C, 100% stablity at 50°C and 80% stablity at pH 3·0-5·0. The apparent Km , Vmax and Kcat values for hydrolyzing polygalacturonic acid were 2·56 mg ml-1 , 163·1 U mg-1 and 277 s-1 respectively. The polygalacturonase presented exo activity and was activated by Mg2+ . The juices treated with polygalacturonase presented increases in transmittance with reduction in colour. CONCLUSIONS: The results suggest that the new lineage P. janthinellum VI2R3M presents a high yield of an exo-polygalacturonase induced by agro-industrial residues, with excellent activity and stability in acidic pH and at 50°C. SIGNIFICANCE AND IMPACT OF THE STUDY: The use of agro-industrial residue to obtain the polygalacturonase can contribute to a decrease enzyme production cost. The results of the activity, stability to acidic pH and excellent performance in the clarification of juices show that the enzyme is promising for industrial application.
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Sucos de Frutas e Vegetais , Penicillium/enzimologia , Poligalacturonase/química , Poligalacturonase/metabolismo , Biotecnologia , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Hidrólise , Peso Molecular , Pectinas/metabolismo , Penicillium/metabolismo , Poligalacturonase/isolamento & purificação , TemperaturaRESUMO
This work analyzed the use of electrocoagulation as substitute for sugarcane clarification process using sulfitation. It was evaluated technological parameters (Icumsa color and turbidity), phenolic compounds content and CIELAB color parameters. Four kinetics of reduction color from sugarcane juice were carried out. The essays were divided according to the voltage applied: 35, 45, 55 and 65â¯V (also based on previous tests). Higher voltage treatments achieved greater reduction of Icumsa color, turbidity and total phenolic compounds. However, none of treatments impacted simple phenolic content analyzed in this work. Tristimulus analysis presented some pattern that went beyond technological analysis, including that 65â¯V essay changed the pigmentation of sugarcane juice and had an early stabilization on chroma. This kind of results could be useful for industry, once they could correlate quality with different color parameters and finally improve the clarification in general with finer settings of technique according to different situations.
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Eletrocoagulação/métodos , Fenóis/química , Saccharum/química , Enxofre/química , Brasil , Cor , Análise de Alimentos , Sucos de Frutas e Vegetais , CinéticaRESUMO
Endopolygalacturonase (EndoPG) from Stereum purpureum was expressed as a soluble protein in Pichia pastoris GS115, where after 3â¯days methanol induction the enzyme activity in the culture supernatant was 40â¯Uâ¯mL-1. After purification by IMAC, SDS-PAGE analysis showed that the molecular weight of EndoPG was approximately 60.0â¯kDa. The carbohydrate content of the recombinant enzyme was estimated to be 67.0% (w/w). The optimum temperature and pH of catalysis were 60-70⯰C and pH of 4.5, respectively. The enzyme was highly stable over the pH range 6.0-8.0 and retained approximately 60% of its initial activity after incubation at 70⯰C for 30â¯min. The enzyme showed a specific activity of 5040.0⯱â¯217â¯Uâ¯mg-1 and hydrolyzed citrus pectin with Vmax and a KM of 4947.10⯱â¯393.63â¯Uâ¯mg-1 and 2.45⯱â¯0.23â¯mgâ¯mL-1, respectively, and showed a catalytic efficiency of 2052.90⯱â¯193.54â¯mLâ¯mg-1â¯s-1. EndoPG alone reduced the viscosity of papaya juice by 20% after 30â¯min, and increased its transmittance about 50% with a concomitant reduction of the color by about 55% after 5â¯h of enzymatic treatment. For apple juice, the relative reduction of viscosity was 30% after 5â¯h, and the reduction of the color was 30% with a 12% increase in transmittance. Supplementation of a commercial enzymatic cocktail for lignocellulose saccharification with EndoPG increased total reducing sugar release by 8.6⯱â¯2.1% against sugar cane bagasse, indicating improved access of the cellulolytic enzymes to the biomass polysaccharides.
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Agaricales/enzimologia , Biotecnologia , Poligalacturonase/química , Poligalacturonase/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Carica/química , Parede Celular/metabolismo , Estabilidade Enzimática , Sucos de Frutas e Vegetais , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Malus/química , Poligalacturonase/genética , Proteínas Recombinantes/genética , Saccharum/citologia , Especificidade por Substrato , TemperaturaRESUMO
ß-glucosidases (BGLs) hydrolyze short-chain cellulooligosaccharides. Some BGLs can hydrolyze anthocyanins and be applied in the clarification process of food industries, especially grape juice and wine. Enzyme immobilization is a valuable tool to increase enzyme stabilization. In this work, Malbranchea pulchella BGL was immobilized on Monoaminoethyl-N-ethyl-agarose ionic support, MANAE-agarose, and Concanavalin A-Sepharose affinity support, Con-A-Sepharose. The formed biocatalysts, denominated BLG-MANAE and BLG-ConA, were applied in the grape juice and red wine clarification. BGL-MANAE and BGL-ConA hyperactivated M. pulchella BGL 10- and 3-fold, respectively. Both biocatalysts showed at least 70% activity at pH range 2-11, until 24â¯h incubation. BGL-MANAE and BGL-ConA showed activity of 60% and 100%, respectively, at 50⯰C, up to 24â¯h. Both biocatalysts were efficiently reused 20-fold. They were stable in the presence of up to 0.1â¯M glucose for 24â¯h incubation, and with 5%, 10% and 15% ethanol kept up to 70% activity. BGL-MANAE biocatalyst was 11% and 25% more efficient than BGL-ConA in clarification of concentrate and diluted wines, respectively. Likewise, BGL-MANAE biocatalysts were 14% and 33% more efficient than the BGL-ConA in clarification of diluted and concentrated juices, respectively. Therefore, the BGL-MANAE biocatalyst was especially effective in red wine and grape juice clarification.
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Antocianinas/metabolismo , Ascomicetos/enzimologia , Sucos de Frutas e Vegetais/análise , Sefarose/análogos & derivados , Vitis/química , Vinho/análise , beta-Glucosidase/metabolismo , Biocatálise , Ativação Enzimática , Estabilidade Enzimática , Enzimas Imobilizadas/antagonistas & inibidores , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Glucose/farmacologia , Concentração de Íons de Hidrogênio , Hidrólise , Sefarose/química , Temperatura , beta-Glucosidase/antagonistas & inibidores , beta-Glucosidase/químicaRESUMO
RESUMEN El uso de polímeros orgánicos para el tratamiento de aguas residuales a través de procesos de coagulación/floculación presenta ventajas sobre el uso de coagulantes inorgánicos, debido a la biodegradabilidad y la baja toxicidad en el agua de estos. El quitosano es un biopolímero que se ha utilizado como coagulante en el tratamiento de aguas residuales. En este estudio, se evaluó el quitosano como coagulante natural utilizado en la clarificación de efluentes piscícolas en tecnología biofloc (BFT) y en sistema de recirculación acuícola (RAS). Se implementó un diseño experimental completamente aleatorizado, de una vía, con efectos fijos. Los ensayos del agua se llevaron a cabo por el método de jar-test, donde se aplicaron dosis de quitosano de 3, 6, 9, 12 y 15 mg/L. Se analizó el efecto estadístico de la dosis de quitosano en la eliminación de la turbidez, sólidos suspendidos totales (SST) y sólidos suspendidos volátiles (SSV) del agua. Se encontró efecto del quitosano sobre la turbidez, dosis de 9 mg/L logró remociones del 88% y valores de 3.9 NTU (con error < 0.05). Sin aplicar quitosano al efluente, se lograron remociones de 78.2 y 76.7% para SST, SSV respectivamente. El quitosano permitió eliminar turbidez del efluente (BFT).
ABSTRACT Using organic polymers for wastewater treatment through coagulation/flocculation processes is more advantageous than current approach based on inorganic coagulants, due to the former's biodegradability and low toxicity in the water. Chitosan is a biopolymer that has been used as coagulant in wastewater treatment. In this study, chitosan was evaluated as a natural coagulant used in the clarification of fish effluents in biofloc technology (BFT) and aquaculture recirculation system (RAS). A one-way completely randomized experimental design with fixed effects was implemented. The water clarification tests were conducted using the jar test method with chitosan doses of 3, 6, 9, 12 and 15 mg/L. The chitosan dose effect was analyzed as natural coagulant on the removal of the water's turbidity, total suspended solids (SST) and volatile suspended solids (SSV). The effect of the chitosan load on the turbidity removal was found, as optimal dose of 9 mg/L for 88% with final turbidity value of 3.9 NTU (with significance < 0.05). In absence of chitosan, only values of 78.2 and 76.7% for SST and SSV were reached, respectively. Chitosan allowed the removal of turbidity from the water (BFT).
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Haemophilus influenzae type b (Hib) is a Gram-negative bacterium, responsible for serious infections, such as pneumonia, sepsis and meningitis, especially in children younger than 5 years old and immunocompromised individuals. The main virulence factor of Hib is its polyribosyl-ribitol-phosphate capsular exopolysaccharide (PRP), which is used in the formulation of Hib vaccines, conjugated to a carrier protein. The production of the conjugated vaccine is complex and costly, particularly the PRP purification process, that comprises several steps of ethanol precipitation and centrifugation, and uses organic solvents and detergents. Targeting a more affordable vaccine that meets the public health systems demands, the Process Development Laboratory of Butantan Institute has been developing a simpler, economical and easily scalable purification process based on tangential flow filtration. In this process, one major bottleneck is the broth clarification step by microfiltration, which results in low PRP recovery and high variability, probably due to membrane fouling. Regarding this matter, a small scale study was previously performed, in order to identify the best operational conditions of relevant process variables, namely transmembrane pressure (TMP), feed flow, and permeate flow. The aim of this work was to scale up the broth clarification step using the defined conditions for these parameters and to perform a critical flux analysis, which is a very useful tool in tangential flow filtration optimization. Although PRP recovery was relatively smaller in the higher scale (68.5% against 97.5%), the permeate flow and TMP profiles were very similar. Analysis of PRP recovery profile indicated that extending dialysis might improve PRP yield. Critical flux of around 35 L.h-1 .m-2 was determined experimentally, which explains the high PRP recovery when a limit permeate flux of 25 L.h-1 .m-2 was employed in the cell clarification step. In conclusion, the process designed for broth clarification is quite promising in terms of product yield and scalability.
Haemophilus influenzae do tipo b (Hib) é uma bactéria Gram-negativa, responsável por infecções graves, como pneumonia, sepse e meningite, especialmente em crianças menores de 5 anos de idade e indivíduos imunocomprometidos. Seu principal fator de virulência é o exopolissacarídeo capsular de poliribosil-ribitol- fosfato (PRP), que é utilizado na formulação de vacinas contra Hib, conjugado a uma proteína carreadora. A produção da vacina conjugada é complexa e onerosa, principalmente o processo de purificação do PRP, caracterizado por várias etapas de precipitação com etanol, centrifugação e uso de solventes orgânicos e detergentes. Buscando uma vacina mais acessível, que possa atender à demanda de sistemas públicos de saúde, o Laboratório de Desenvolvimento de Processos vem desenvolvendo nos últimos anos um método de purificação mais simples, econômico e facilmente escalonável, baseado em filtração tangencial. Nesse processo, um dos gargalos identificados é a etapa de separação celular por microfiltração, que apresentava baixa recuperação de PRP e alta variabilidade dos resultados, provavelmente relacionados ao fenômeno de fouling. Um estudo em pequena escala foi realizado previamente para identificar as melhores condições de variáveis operacionais relevantes - pressão transmembrana (TMP), fluxo de entrada e fluxo do filtrado. O presente trabalho teve como objetivos escalonar o processo, mantendo essas condições, e realizar uma análise do fluxo crítico do filtrado, ferramenta bastante útil para a otimização da filtração tangencial. Embora a recuperação de PRP tenha sido relativamente menor no processo escalonado (68,5% contra 97,5%), os perfis de fluxo do filtrado e de TMP se mostraram muito semelhantes, e as análises da tendência de recuperação mostram que um aumento no número de diavolumes utilizado pode contornar essa questão. O valor de fluxo crítico determinado experimentalmente foi próximo de 35 L.h-1 .m-2 , o que corrobora os bons resultados obtidos com o uso de fluxo limite de 25 L.h-1 .m-2 para o filtrado no processo de separação celular. Os resultados obtidos mostram que o desenho de processo estabelecido para a clarificação de PRP é bastante promissor em termos de rendimento de PRP e escalabilidade do processo.
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In the present study, we prepared two different magnetic biocatalysts of pectinase and cellulase: carrier-free magnetic CLEAs (CLEA-MP*) and immobilization on glutaraldehyde-activated magnetite (Enz-Glu-MP*). The biocatalysts were compared to their magnetic properties, immobilization parameters, stability and grape juice clarification. Enz-Glu-MP* presented higher magnetic properties than CLEA-MP*, whereas this presented higher surface area and pore volume. The KM of the enzyme immobilized on Enz-Glu-MP* was 25.65mM, lower in comparison to the CLEA-MP* (33.83mM). On the other hand, CLEA-MP* was the most active and stable biocatalyst, presenting higher recovered activity (33.4% of cellulase), higher thermal stability (2.39 stabilization factor) and improved reusability (8cycles). The integration of magnetic technology with enzymatic immobilization emerges as a possibility to increase the recover and reuse of biocatalysts for application in juice technology.
Assuntos
Celulase/química , Celulase/metabolismo , Óxido Ferroso-Férrico/química , Sucos de Frutas e Vegetais/análise , Poligalacturonase/química , Poligalacturonase/metabolismo , Vitis/química , Biocatálise , Estabilidade Enzimática , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Glutaral/química , Cinética , Solubilidade , TemperaturaRESUMO
Este artículo de revisión ayudará a los odontólogos a mejorar su comprensión de los procedimientos de aclaramiento dental, tipos de aclaramientos, componentes activos, mecanismos de acción y sus efectos sobre las estructuras dentales, materiales de obturación y la adhesión. También se mostrará un nuevo sistema, el cual consiste en tres pasos denominados ABC que signifi ca Activate, Bleach and Condition (activación, blanqueamiento y acondicionamiento). Al realizar estas tres etapas se garantiza un tratamiento de aclaramiento muy efi caz, seguro y sobre todo sin dolor (AU)
This review article will help dentists to improve their understanding of dental clearance procedures, types of clearings, active components, mechanisms of action and their eff ects on dental structures, sealing materials and adhesion. It will also show a new system which consists of three steps called ABC that means Activate, Bleach, and Condition. Performing these three stages ensures a very effective, safe and especially painless clearance treatment (AU)
Assuntos
Humanos , Feminino , Adulto , Estética Dentária , Peróxido de Hidrogênio , Clareamento Dental , Resinas Compostas , Colagem Dentária , Esmalte Dentário , Infiltração Dentária , Propriedades de Superfície , Descoloração de DenteRESUMO
Viral vectors are important in medical approaches, such as disease prevention and gene therapy, and their production depends on efficient prepurification steps. In the present study, an aqueous two-phase micellar system (ATPMS) was evaluated to extract human adenovirus type 5 particles from a cell lysate. Adenovirus was cultured in human embryonic kidney 293 (HEK-293) cells to a concentration of 1.4 × 1010 particles/mL. Cells were lysed, and the system formed by direct addition of Triton X-114 in a 23 full factorial design with center points. The systems were formed with Triton X-114 at a final concentration of 1.0, 6.0, and 11.0% (w/w), cell lysate pH of 6.0, 6.5, and 7.0, and incubation temperatures at 33, 35, and 37 °C. Adenovirus particles recovered from partition phases were measured by qPCR. The best system condition was with 11.0% (w/w) of Triton X-114, a cell lysate pH of 7.0, and an incubation temperature at 33 °C, yielding 3.51 × 1010 adenovirus particles/mL, which increased the initial adenovirus particles concentration by 2.3-fold, purifying it by 2.2-fold from the cell lysate, and removing cell debris. In conclusion, these results demonstrated that the use of an aqueous two-phase micellar system in the early steps of downstream processing could improve viral particle extraction from cultured cells while integrating clarification, concentration, and prepurification steps.
Assuntos
Adenoviridae/isolamento & purificação , Extratos Celulares/química , Micelas , Água/química , Células Cultivadas , Vetores Genéticos/isolamento & purificação , Células HEK293 , HumanosRESUMO
Viral vectors are important in medical approaches, such as disease prevention and gene therapy, and their production depends on efficient prepurification steps. In the present study, an aqueous two-phase micellar system (ATPMS) was evaluated to extract human adenovirus type 5 particles from a cell lysate. Adenovirus was cultured in human embryonic kidney 293 (HEK-293) cells to a concentration of 1.4 × 1010 particles/mL. Cells were lysed, and the system formed by direct addition of Triton X-114 in a 23 full factorial design with center points. The systems were formed with Triton X-114 at a final concentration of 1.0, 6.0, and 11.0% (w/w), cell lysate pH of 6.0, 6.5, and 7.0, and incubation temperatures at 33, 35, and 37 °C. Adenovirus particles recovered from partition phases were measured by qPCR. The best system condition was with 11.0% (w/w) of Triton X-114, a cell lysate pH of 7.0, and an incubation temperature at 33 °C, yielding 3.51 × 1010 adenovirus particles/mL, which increased the initial adenovirus particles concentration by 2.3-fold, purifying it by 2.2-fold from the cell lysate, and removing cell debris. In conclusion, these results demonstrated that the use of an aqueous two-phase micellar system in the early steps of downstream processing could improve viral particle extraction from cultured cells while integrating clarification, concentration, and prepurification steps.
Assuntos
Humanos , Vetores Genéticos/isolamento & purificação , Água/químicaRESUMO
ABSTRACT The aim of this study is the production, purification, and characterisation of thermostable raw starch hydrolyzing α-amylase produced by Bacillus mojavensis SO-10. The maximum production conditions of α-amylase were found at 36th hour, 35 °C and pH 7.0. We utilized three steps to purify the thermostable α-amylase and as a result, 34-fold and 18% yield were obtained. The molecular weight of purified α-amylase was determined as 73 kD. The Km and Vmax rates were detected as 0.010 mM and 3.38 µmol min−1, respectively. This purified α-amylase exhibited the highest activity at pH 5.0-6.0 and 70 ºC and showed stability over a wide variety of pH and temperature at 4.0-8.0, and 40-50 ºC, respectively. The thermostable purified α-amylase exhibited stability in the presence of denaturing agents and heavy metal ions. The purified enzyme hydrolyzed the raw starches of corn and wheat grains in the ratio of 36.7% and 39.2% respectively. The end-yields of soluble starch hydrolysis were analyzed by thin-layer chromatography (TLC). In addition, the usage of purified α-amylase in clarification of apple juice and domestic washing detergent industries were evaluated.