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| Registros recuperados: 112 | |
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| Fileti,Ana Maria Frattini; Fischer,Gilvan Anderson; Santana,José Carlos Curvelo; Tambourgi,Elias Basile. |
| The main aim of this study was to optimize the conditions for bromelain extraction by reversed micelles from pineapple juice (Ananas comosus). The purification was carried out in batch extraction and a micro-column with pulsed caps for continuous extraction. The cationic micellar solution was made of BDBAC as a surfactant, isooctane as a solvent and hexanol as a co-solvent. For the batch process, a purification factor of 3 times at the best values of surfactant agent, co-solvent and salt concentrations, pH of the back and forward extractions were, 100 mM, 10% v/v, 1 M, 3.5 and 8, respectively. For the continuous operation, independent variables optimal point was determined: ratio between light phase flow rate and total flow rate equal to 0.67 and 1 second... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Reversed micelles; Liquid-liquid extraction; Bromelain; Pineapple; Optimization; Surface response. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132009000500021 |
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| Garlapati,Vijay Kumar; Vundavilli,Pandu Ranga; Banerjee,Rintu. |
| The aim of this work was to apply a modeling integrated optimisation approach for a complex, highly nonlinear system for an extracellular lipase extraction process. The model was developed using mutation, crossover and selection variables of Differential Evolution (DE) based on central composite design of Response Surface Methodology. The experimentally validated model was optimized by DE, a robust evolutionary optimization tool. A maximum lipase activity of 134.13 U/gds (more than 36.28 U/gds compared to one variable at a time approach) was observed with the DE-stated optimum values of 25.01% dimethyl sulfoxide concentration, 40 mM buffer, 128.52 min soaking time and 35ºC with the DE control parameters, namely number of population, generations, crossover... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Modeling; Optimization; Lipase extraction; Response surface methodology; Differential evolution; Solid state fermentation. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132013000500001 |
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| Mrudula,Soma; Shyam,Nidhi. |
| Optimization of culture conditions and immobilization parameters for alkaline protease production was carried out by employing Bacillus megaterium MTCC2444. The partially purified enzyme was tested for its stability in the presence of oxidants, surfactants and commercial detergents. The optimum temperature, pH, incubation time and inoculum size were 55 ºC, 11, 48 h, 1 %, respectively. Calcium alginate was used as the immobilization matrix and the effects of gel concentration, bead size, age of immobilized cells, solidification period and initial biomass concentration on alkaline protease production and cell leakage were investigated. The results indicated that the immobilization was most effective with 4 % gel concentration, bead size of 3 mm, 24 h aged... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Optimization; Immobilized cells; Cell leakage; Detergent; Oxidant stability. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132012000100017 |
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| Sambiassi,César; Escalada,Andrea M.; Schmalko,Miguel E.. |
| The objective of this research was the extraction optimization of water soluble compounds of yerba maté. Measures variables were extract concentration and weight of leaves and twigs. Controlled variables were time and temperature of extraction and water/solid relation. A surface response method of three variables was used as experimental design, with 20 experiences in each case. The range of each variable, defined in the experimental design, was: extraction time, 13.2 to 46.8 minutes; temperature, 48.2 to 81.8°C and water solid relation, 4.64 to 11.36 g water/100 g of dry solid. Extract weight varied from 13.14 to 29.56 g in leaves and 8.98 to 16.32 g in twigs (each one per 100 g of dry solid). Extract concentration varied between 2.17 and 3.43 g/100 ml in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Yerba maté; Soluble compounds; Optimization. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132002000200010 |
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| Kumari,Annapurna; Mahapatra,Paramita; Banerjee,Rintu. |
| Optimization of lipase production by Enterobacter aerogenes was carried out using response surface methodology (RSM) where the statistical model was obtained by fractional factorial central composite design. The influence of various physico-chemical parameters, viz. temperature, oil concentration, inoculum volume, pH and incubation period on lipase production was examined. Optimization of physico-chemical parameters resulted 1.4- fold increase in lipase activity. The optimum levels of parameters were 34°C, oil concentration 3%, inoculum volume 7%, pH 7 and incubation time 60 h for obtaining a maximum lipase activity of 27.25 U/ml. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Central composite design; Enterobacter aerogenes; Lipase; Optimization; Parameter; Response Surface Methodology. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132009000600005 |
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| Xavier,Marcelo Fonseca; Lopes,Toni Jefferson; Quadri,Mara Gabriela Novy; Quadri,Marintho Bastos. |
| The aim of this work was to extract anthocyanins from the red cabbage. Batch studies under several extraction conditions indicated that acetic acid in aqueous solution (10% V/V) was the best solvent, used in the proportion of 0.25 g of red cabbage mL-1. At this condition, column assays were carried out to evaluate the influence of the ionic force, pH, solvent flow rate, recirculated volume of red cabbage juice and the mass of red cabbage. Results showed that the pH, recirculation and mass of red cabbage had statistically significant effects, where the optimum operation conditions found for the process were pH 2.3, recirculation volume of the solvent 0.83 L and mass of red cabbage 50 g. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Anthocyanins; Extraction; Red cabbage; Experimental design; Optimization. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132008000100018 |
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| Cunha,Fabíola Pessoa da; Costa,Luana Janine Lopes da; Fernandes,Ana Josane Dantas; Souza,Tatiane Pereira de; Soares,Luiz Alberto Lira. |
| The purpose of this study was to evaluate the influences from variables of preparation on dry residue and total tannins from macerates of Astronium urundeuva barks. Thus, a 3 ² factorial design was used to study the importance of plant proportion (10, 15 and 20 %, w/v) and the ethanol concentration (40, 60 and 80 %, v/v) on the selected response. Mathematical models were fitted according to experimental data. The validated equations were used to generate response surfaces. The analysis of the surfaces showed that the optimum conditions to obtain extractive preparations with high extractive efficiency for tannins were: 10 % (w/v) of plant with ethanol 40 % (v/v) as solvent. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Astronium urundeuva; Extraction; Optimization; Factorial Design. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132009000300017 |
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| Singh,Jagdish; Kaur,Pawandeep. |
| The aim of this work was to isolate the potent bacterial strains for the production of cellulose enzyme. A total 30 bacterial isolates showed positive results for the cellulase production but highest enzyme activity was shown by isolate JS 14. From the morphological and biochemical reactions, the isolate was identified as Bacillus sp. Cellulase production was studied by this strain using response surface methodology (RSM). A central composite design (CCD) quadratic response surface was applied to explicate the parameters that significantly affected cellulase production in solid substrate fermentation (SSF). The wheat bran concentration and incubation period were significant factors. The process parameters optimized with response surface methodology was... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cellulase; Response surface methodology; Optimization. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132012000400004 |
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| Manikandan,Muthu; Kannan,Vijayaraghavan; Velikonja,Blagajana Herzog; Paic,Lejla. |
| The production of halophilic thermostable protease by Haloferax lucentensis VKMM 007 was optimized using a statistical approach. In accordance with factorial design, soluble starch, gelatin, KCl and MgSO4 were selected among 27 variables tested. Next, a second-order quadratic model was estimated and optimal medium concentrations were determined based on quadratic regression equation generated by model. These were 5.14 g L-1 of KCl, 6.57 g L-1of MgSO4, 9.05 g L-1of gelatin and 5.27 g L-1of soluble starch in high salts media supplemented with 0.5% (w/v) of beef extract and peptone, respectively. In these optimal conditions, the obtained protease concentration of 6.80 U mL-1 was in agreement with the predicted protease concentration and was further improved... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cultivation media; Haloferax lucentensis; Response surface methodology; Optimization; Halophilic protease. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822011000200050 |
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| Malheiros,Patrícia S.; Sant’Anna,Voltaire; Todorov,Svetoslav D.; Franco,Bernadette D.G.M.. |
| Lactobacillus sakei subsp. sakei 2a is a bacteriocinogenic lactic acid bacterium isolated from Brazilian pork sausage, capable of inhibiting the growth of microbial pathogens, mainly Listeria monocytogenes. In order to optimize bacteriocin production for industrial applications, this study evaluated the effect of supplementation of MRS broth with glucose, Tween 20, Tween 80, sodium citrate, potassium chloride and cysteine, and effect of the initial pH and temperature of incubation of the medium on production of bacteriocins by L. sakei 2a. Adding glucose and Tween 20 to the medium, an initial pH of 5.0 or 5.5, and incubation temperatures of 25 °C or 30 °C resulted to the highest bacteriocin yields. Thus, a 24 factorial design with the four variables was... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lactobacillus sakei; Bacteriocin; Response surface methodology; Optimization. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822015000300825 |
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| Amena,S.; Vishalakshi,N.; Prabhakar,M.; Dayanand,A.; Lingappa,K. |
| L-asparaginase is an anti-neoplastic agent used in the lymphoblastic leukaemia chemotherapy. In the present study a novel strain, Streptomyces gulbargensis was explored for the production of extra-cellular L-asparaginase using groundnut cake extract. The optimum pH, temperature, inoculum size and agitation speed for enzyme production were pH 8.5, 40ºC, 1x10(8)spores/ml and 200 rev/min respectively. Maltose (0.5%) and L-asparagine (0.5%) proved to be the best carbon and nitrogen sources respectively. The enzyme was purified 82.12 fold and the apparent molecular weight of the enzyme was found to be 85 kDa. The optima pH and temperature for the enzyme were 9.0 and 40ºC respectively. The enzyme was more stable at the alkaline pH than at the acidic one and it... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: L-asparaginase; Streptomyces gulbargensis; Groundnut cake extract; Optimization; Purification. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822010000100025 |
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| Yuan,Baojing; Chi,Xiaoyan; Zhang,Rijun. |
| This study aimed at optimizing the medium of a new Ganoderma lucidum strain CAU5501 to enhance the yield of exopolysaccharides (EPS) and mycelial growth. Firstly, the suitable level of glucose, magnesium, phosphate and C/N ratio was determined by single factor experiment. Subsequently, the optimum concentrations of these medium components were investigated using the orthogonal matrix method. The results indicated that the higher levels of EPS were correlated with the level of cell growth when glucose concentration was studied (data no show). The optimum medium for EPS yield was found to be 70 g/l glucose, 5 C/N ratio, 2.5 g/l KH2PO4, 0.75 g/l MgSO4·7H2O, and for mycelial growth was 50 g/l glucose, 5 C/N ratio, 1.5 g/l KH2PO4, 0.5 g/l MgSO4·7H2O. When... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Optimization; Exopolysaccharides; Ganoderma lucidum; Orthogonal matrix method; Submerged culture. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822012000200009 |
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| Registros recuperados: 112 | |
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