CAMPERI Silvia Andrea
Preparation and characterisation of immobilised metal ion hollow-fibre polysulphone membranes. Their application in high-speed pectic enzyme fractionation.
S.A. CAMPERI; M. GRASSELLI; E. E. SMOLKO; O. CASCONE
Elsevier Science Ltd.
Año: 2004 vol. 39 p. 1017 - 1017
Chelating hollow-fibre membranes were prepared from epoxy-activated polysulphone microfiltration fibres by introducing iminodiacetic acid (IDA) groups in the presence of dimethyl sulphoxide. Fibres with 160, 350 and 620 m mol epoxy groups/ml provided ligand densities of 69, 134 and 203 mmol IDA/ml and pure water fluxes of 7.8, 5.8 and 0.42 cm/min, respectively. However, lysozyme capacity was close to 4 mmol/ml for all fibres. Adsorption isotherms for lysozyme and pectinesterase did not fit Langmuir-type curves and the existence of two types of ligand (A and B) with different accessibility to proteins was assumed. For pectinesterase, maximum capacities of 5100 and 2900 U/ml and dissociation constants of 25 and 316 U/ml were found, respectively, for ligands A and B. For lysozyme, maximum capacities were 2.9 and 0.9 mmol/ml and dissociation constants 5.0 and 102 mM, respectively, for said ligands. A cartridge assembled with IDA hollow fibres had a dynamic capacity for pectinesterase of 7509 U/ml. Productivity of this cartridge for pectic enzyme fractionation was 750 pectinesterase U/ml min, far higher than that obtained with a chelating soft gel (81 pectinesterase U/ml min).