Encontrados 11 documentos, a visualizar página 1 de 2
Studies on the interaction of the carbohydrate binding module 3 from the Clostr...
Machado, João; Araújo, Adriano; Pinto, João Ricardo; Gama, F. M.The adsorption of a carbohydrate binding module (CBM3) from the Clostridium thermocellum scaffolding protein (CipA) to cellulose was analysed in this work. The effect of CBM-PEG on the drainability of E. globulus and P. sylvestris pulps and on the physical properties of the respective papersheets was also studied. The CBM binding to cellulose is often described as “irreversible”, but this classification does no...
Quantification of the CBD-FITC conjugates surface coating on cellulose fibres
Pinto, João Ricardo; Amaral, A. L.; Ferreira, E. C.; Mota, M.; Vilanova, Manuel; Ruel, Katia; Gama, F. M.Background Cellulose Binding Domains (CBD) were conjugated with fluorescein isothiocyanate (FITC). The surface concentration of the Binding Domains adsorbed on cellulose fibres was determined by fluorescence image analysis. Results For a CBD-FITC concentration of 60 mg/L, a coating fraction of 78% and 110% was estimated for Portucel and Whatman fibres, respectively. For a saturating CBD concentration, using Wh...
Textile depilling : superior finishing using cellulose-binding domains with res...
Ramos, Reinaldo Rodrigues; Pinto, João Ricardo; Mota, M.; Sampaio, L.; Gama, F. M.Textile fabric depilling is an important industrial application of cellulases. The depilling effect and achievement of desirable touch properties are among the applications sought by users. This process, although effective, is associated with significant tensile strength loss. The depilling mechanism is still a subject of controversy. In this work, we introduce a new perspective in understanding of the depillin...
Development of a method using image analysis for the measurement of cellulose-b...
Pinto, João Ricardo; Amaral, A. L.; Carvalho, Joana; Ferreira, E. C.; Mota, M.; Gama, F. M.The surface concentration of CBD-FITC conjugates, adsorbed on cellulose fibers, was determined by image analysis. The program consists of two scripts, the first dedicated to the elaboration of the calibration curve. The emission of fluorescent light, detected by image analysis, is correlated with the concentration of CBD solutions. This calibration is then used (second script) to determine the concentration of ...
Production of cellulose-binding domains by proteolysis : studies on the adsorpt...
Pinto, João RicardoTese de Doutoramento em Engenharia Química e Biológica ; Most cellulose degrading enzymes are composed of modular structures. In the case of fungi, cellulases are formed by a catalytic domain (CD) and by a cellulose-binding domain (CBD), interconnected through a highly glycosylated protein linker. These enzymes are used for paper production, either to allow a more efficient refinement or to improve the paper s...
Large-scale production of cellulose-binding domains : adsorption studies using ...
Pinto, João Ricardo; Carvalho, Joana; Mota, M.; Gama, F. M.A method for the gram-scale production of cellulose-binding domains (CBD) through the proteolytic digestion of a commercial nzymatic preparation (Celluclast) was developed. The CBD obtained, isolated from Trichoderma reesei cellobiohydrolase I, is highly pure and heavily glycosylated. The purified peptide has a molecular weight of 8.43 kDa, comprising the binding module, a part of the linker, and about 30% gly...
Determinação da concentração de CBD-FITC adsorvidos em fibras por análise de im...
Amaral, A. L.; Pinto, João Ricardo; Carvalho, Joana; Ferreira, E. C.; Gama, F. M.Neste trabalho, foi elaborado um programa de processamento e análise de imagem para a determinação da quantidade de CBD-FITC adsorvido em fibras de celulose. Este programa consiste em duas fases em que a primeira se dedica à elaboração da curva de calibração e a segunda à determinação da concentração do CBD-FITC adsorvido. Para a elaboração da curva de calibração é necessário proceder a uma prévia aquisição de ...
Textile depilling : use of enzymes and cellulose binding domains
Ramos, Reinaldo Rodrigues; Pinto, João Ricardo; Sampaio, L.; Mota, M.; Gama, F. M.Textile fabrics biopolishing is one of the most important industrial application of cellulases. These are widely used to remove fibrils and fuzz fibres from cotton fabrics, or to produce the “stone-washed” look of denim garments. The depilling effect and the achievement of desirable touch properties are among the applications sought by the users. This process, although effective, is associated to a significant ...
Studies on the cellulose-binding domains adsorption to cellulose
Pinto, João Ricardo; Moreira, Susana; Mota, M.; Gama, F. M.Cellulose-binding domains (CBD) are modular peptides, present in many glycanases, which anchor these enzymes to the substrate. In this work, the effect of CBD adsorption on the surface properties of a model cellulose, Whatman CF11, was studied. The methods applied include inverse gas chromatography (IGC), ESCA, X-ray diffraction, and scanning electron microscopy (SEM). The CBD partition affinity (0.85 L/g) was ...
Improving papermaking with cellulose-binding domains
Pinto, João Ricardo; Amaral, Emília; Costa, Ana Paula; Gama, F. M.; Duarte, Ana Paula CoelhoA influência dos domínios de ligação à celulose (CBDs) nas propriedades das fibras celulósicas foi estudada em diferentes amostras de pasta, nomeadamente em pastas recicladas (de papéis kraft e de escritório) e químicas (Eucalipto e Pinho). Foi observado que as fibras tratadas com CBDs exibiam melhorias na drenabilidade da pasta, com redução do ºSR até 15% e um aumento da permeabilidade ao ar das folhas de past...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||