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| Registros recuperados: 11 | |
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| Palma,Mauri Sergio Alves; Horn,Harald; Zilli,Mario; Pigatto,Gisele; Converti,Attilio. |
| This work aimed to develop a new economic enzymatic process to treat the phenolic pollutants using pure tyrosinase in stirred vessel and adopting temperature (T), pH, rotational speed (N), initial phenol (C P,o) and enzyme (C T) concentrations as independent variables. Experimental data of the residual phenol concentration (C P) were used to calculate the oxidation efficiency (η), initial oxidation rate (-r o) and time required to reach the end of reaction (t) that were selected as the responses. Under the optimal conditions (T = 45°C, pH 6.6, N = 400 rpm, C P,o = 100 ppm and C T = 50 U/mL), η was 88.1%, -r o = 10.2 mg L-1 min-1, t = 40 min. These results suggested that tyrosinase-rich crude extracts from vegetable byproducts could be quite promising. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Phenols; Tyrosinase; Wastes; Enzymatic treatment. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132013000400016 |
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| Max,Belén; Salgado,José Manuel; Rodríguez,Noelia; Cortés,Sandra; Converti,Attilio; Domínguez,José Manuel. |
| This work provides a review about the biotechnological production of citric acid starting from the physicochemical properties and industrial applications, mainly in the food and pharmaceutical sectors. Several factors affecting citric acid fermentation are discussed, including carbon source, nitrogen and phosphate limitations, pH of culture medium, aeration, trace elements and morphology of the fungus. Special attention is paid to the fundamentals of biochemistry and accumulation of citric acid. Technologies employed at industrial scale such as surface or submerged cultures, mainly employing Aspergillus niger, and processes carried out with Yarrowia lipolytica, as well as the technology for recovering the product are also described. Finally, this review... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Citric acid; Fermentation; Review; Aspergillus niger. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822010000400005 |
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| Torrado,Ana María; Cortés,Sandra; Salgado,José Manuel; Max,Belén; Rodríguez,Noelia; Bibbins,Belinda P; Converti,Attilio; Domínguez,José Manuel. |
| Valencia orange (Citrus sinensis) peel was employed in this work as raw material for the production of citric acid (CA) by solid-state fermentation (SSF) of Aspergillus niger CECT-2090 (ATCC 9142, NRRL 599) in Erlenmeyer flasks. To investigate the effects of the main operating variables, the inoculum concentration was varied in the range 0.5·10³ to 0.7·10(8) spores/g dry orange peel, the bed loading from 1.0 to 4.8 g of dry orange peel (corresponding to 35-80 % of the total volume), and the moisture content between 50 and 100 % of the maximum water retention capacity (MWRC) of the material. Moreover, additional experiments were done adding methanol or water in different proportions and ways. The optimal conditions for CA production revealed to be an... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Orange peel; Citric acid; Aspergillus niger; Solid-state fermentation. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822011000100049 |
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| Arias,Cesar Andres Diaz; Marques,Daniela de Araujo Viana; Malpiedi,Luciana Pellegrini; Maranhão,Andrea Queiroz; Parra,Dulcineia Abdalla Saes; Converti,Attilio; Pessoa Junior,Adalberto. |
| Abstract Antibodies and antibody fragments are nowadays among the most important biotechnological products, and Pichia pastoris is one of the most important vectors to produce them as well as other recombinant proteins. The conditions to effectively cultivate a P. pastoris strain previously genetically modified to produce the single-chain variable fragment anti low density lipoprotein (-) under the control of the alcohol oxidase promoter have been investigated in this study. In particular, it was evaluated if, and eventually how, the carbon source (glucose or glycerol) used in the preculture preceding cryopreservation in 20% glycerol influences both cell and antibody fragment productions either in flasks or in bioreactor. Although in flasks the volumetric... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Pichia pastoris; ScFv antibody fragment; Cryopreservation; Expression; Carbon source. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822017000300419 |
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| Palazzi,Emilio; Molinari,Francesco; Fabiano,Bruno; Pessoa Jr,Adalberto; Converti,Attilio. |
| A relatively complex network of reactions has been investigated, using as a network model the isothermal batch esterification of acetic acid with ethanol in n-heptane catalyzed by lyophilized mycelium of Aspergillus oryzae. The kinetic analysis was firstly carried out on the whole system, without any simplification, by means of the well-known integral method. Owing to the poor results obtained by this way, we developed an alternative approach, combining initial rates and integral analysis and reducing the number of empirical parameters to be determined by the use of equilibrium data. All the values of the parameters calculated according to this "composite" approach to kinetic analysis well correlate with experimental data. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aspergillus oryzae; Complex network; Enzyme reactions; Esterification; Organic solvent. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822011000100048 |
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| Sene,Luciane; Converti,Attilio; Secchi,Geslaine Aparecida Ribeiro; Simão,Rita de Cássia Garcia. |
| The world practice of using agrochemicals for long periods, in an indiscriminated and abusive way, has been a concern of the authorities involved in public health and sustainability of the natural resources, as a consequence of environmental contamination. Agrochemicals refer to a broad range of insecticides, fungicides and herbicides, and among them stands out atrazine, a herbicide intensively used in sugarcane, corn and sorghum cultures, among others. Researches have demonstrated that atrazine has toxic effects in algae, aquatic plants, aquatic insects, fishes and mammals. Due to the toxicity and persistence of atrazine in the environment, the search of microbial strains capable of degrading it is fundamental to the development of bioremediation... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Atrazine; Biodegradation; Bacteria; Fungi; Microbial consortium. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132010000200030 |
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| Marques,Daniela A. Viana; Cunha,Márcia N. Carneiro; Araújo,Janete M.; Lima-Filho,José L.; Converti,Attilio; Pessoa-Jr,Adalberto; Porto,Ana L. Figueiredo. |
| Clavulanic acid is a β-lactam antibiotic which has a potent β-lactamase inhibiting activity. In order to optimize its production by the new isolate Streptomyces DAUFPE 3060, the influence of two independent variables, temperature and soybean flour concentration, on clavulanic acid and biomass concentrations was investigated in 250 mL-Erlenmeyers according to a 2² central composite design. To this purpose, temperature and soybean flour (SF) concentration were varied in the ranges 26-34°C and 10-50 g/L, respectively, and the results evaluated utilizing the Response Surface Methodology. The experimental maximum production of clavulanic acid (629 mg/L) was obtained at 32°C and 40 g/L SF after 48 h, while the maximum biomass concentration (3.9 g/L) at 30°C and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Clavulanic acid; Response surface methodology; Production; Optimization; Streptomyces sp. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822011000200030 |
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| Marques,Daniela A. Viana; Santos-Ebinuma,Valéria de Carvalho; Oliveira,Patrícia Maria Sobral de; Lima,Gláucia Manoella de Souza; Araújo,Janete M.; Lima-Filho,José L.; Converti,Attilio; Pessoa-Júnior,Adalberto; Porto,Ana L.F.. |
| The selection of new microorganisms able to produce antimicrobial compounds is hoped for to reduce their production costs and the side effects caused by synthetic drugs. Clavulanic acid is a β-lactam antibiotic produced by submerged culture, which is widely used in medicine as a powerful inhibitor of β-lactamases, enzymes produced by bacteria resistant to antibiotics such penicillin and cephalosporin. The purpose of this work was to select the best clavulanic acid producer among strains of Streptomyces belonging to the Microorganism Collection of the Department of Antibiotics of the Federal University of Pernambuco (DAUFPE). Initially, the strains were studied for their capacity to inhibit the action of β-lactamases produced by Klebsiella aerogenes ATCC... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Clavulanic acid; Β-lactamases inhibitor; Streptomyces screening; Submerged culture; Growth kinetics. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822014000300022 |
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| Converti,Attilio; Faveri,Danilo de; Perego,Patrizia; Barghini,Paolo; Ruzzi,Maurizio; Sene,Luciane. |
| Vanillin production from ferulate was studied using different recombinant strains of Escherichia coli. To prevent the occurrence of aerobic conditions and then possible product oxidation, tests were performed in Erlenmeyer flasks under mild mixing (150 rpm). Among other transformants, E. coli JM109(pBB1) appeared to be the best vanillin producer, being able to convert no less than 95% of starting ferulate to the product within 1h. This yield decreased down to 72% after 72h, likely because of a non-specific oxidase activity responsible for vanillin oxidation to vanillate. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Vanillin; Ferulate; Escherichia coli JM109; Recombinant strains. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822003000500037 |
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| Registros recuperados: 11 | |
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