Encontrados 5 documentos, a visualizar página 1 de 1
Effect of the agitation on the adsorption and hydrolytic efficiency of cutinase...
O'Neill, Jaime Alexandre Antunes; Araújo, Rita; Casal, Margarida; Gübitz, Georg M.; Paulo, Artur CavacoThe effect of agitation on adsorption, desorption and hydrolytic efficiency of a native and a genetically modified cutinase (L182A) on polyethylene terephthalate fibres is reported in this paper. The effect of mechanical agitation was studied using a shaker bath with orbital agitation and a Rotawash machine with vertical agitation with and without extra steel discs inside the reaction pots. The results obtained...
Tailoring cutinase activity towards polyethylene terephthalate and polyamide 6,...
Araújo, Rita; Silva, Carla Manuela; O'Neill, Jaime Alexandre Antunes; Micaelo, N. M.; Gübitz, Georg M.; Soares, Cláudio M.; Casal, MargaridaCutinase from Fusarium solani pisi was genetically modified near the active site, by site-directed mutagenesis, to enhance its activity towards polyethylene terephthalate (PET) and polyamide 6,6 (PA 6,6) fibers. The mutations L81A, N84A, L182A, V184A and L189A were done to enlarge the active site in order to better fit a larger polymer chain. Modeling studies have shown enhanced free energy stabilization of mod...
Cutinase : a new tool for biomodification of synthetic fibers
Silva, Carla Manuela; Carneiro, Ana Filipa Gonçalves da Costa; O'Neill, Jaime Alexandre Antunes; Fonseca, Luís P.; Cabral, J. M. S.; Gübitz, Georg M.This paper describes two methods to monitor esterase hydrolysis at the surface of polyester fibres (PETPolyethylene terephthalate). The hydroxyl groups were determined on the fibre surface by alkaline reaction with a reactive dye (CI Reactive Black 5) and colour intensity was determined using a reflectance spectrophotometer. The terephthalic acid solution formed was also quantified after reaction with peroxide ...
Monitoring biotransformations in polyesters
O'Neill, Jaime Alexandre Antunes; Paulo, Artur CavacoThis paper describes two methods to monitor esterase hydrolysis at the surface of polyester fibres (PET-Polyethylene terephthalate). The hydroxyl groups were determined on the fibre surface by alkaline reaction with a reactive dye (CI Reactive Black 5) and colour intensity was determined using a reflectance spectrophotometer. The terephthalic acid solution formed was also quantified after reaction with peroxide...
Efeito de solventes orgânicos nas propriedades de fibras sintéticas
O'Neill, Jaime Alexandre AntunesA modificação de fibras sintéticas pode ser feita por via enzimática, com enzimas como as lipases, proteases e nitrilases. Nestes tratamentos enzimáticos existe o problema da acessibilidade das enzimas às fibras, devido à natureza hidrofóbica das mesmas. Este problema de acessibilidade existe também durante o tingimento destes materiais sintéticos, pelo que por vezes é necessário recorrer a carriers, que vão ba...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||