RESUMO
The adsorption of commercial trypsin (Try) onto epichlorohydrin cross-linked alginate-guar gum matrix has been studied at equilibrium in batch and in fixed bed column. Experiments were conducted to study the effect of ionic strength, temperature and to obtain a thermodynamic characterization of the adsorption process. The resulting adsorption isotherm fitted the Hill equation. Experimental breakthrough curve profiles were compared with the theoretical breakthrough profiles obtained from the mathematical model, bed depth service time. At pH 5.0, 1.0 g hydrated matrix adsorbed 480.0 milligram of Try per gram of dried bed. The desorption process showed 80% of Try recovery in 50 mM phosphate buffer, pH 7.00-500 mM NaCl-20% propylene glycol. The obtained results were applied to an adsorption/washing/desorption process with fresh pancreas homogenate yielded 20% of recovery and 5.7 purification factor of Try. The matrix remained functional until the fifth cycle of repeated batch enzyme adsorption. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 2018.
Assuntos
Alginatos/química , Pâncreas/metabolismo , Tripsina/química , Tripsina/metabolismo , Adsorção , Animais , Bovinos , Concentração de Íons de Hidrogênio , TermodinâmicaRESUMO
This work addresses the obtaining and characterization of alginate-guar gum matrix, cross-linked with epichlorohydrin in the presence of different flexible chain polymers: polyvinyl alcohol, polyvinyl pyrrolidine and Pluronic® F68. These matrixes were used for the adsorption of chymotrypsinogen and showed an increasing uptake in presence of the flexible chain polymer in the sense: noneâ¯<â¯Pluronic 68â¯<â¯polyvinyl pyrrolidineâ¯<â¯polyvinyl alcohol. The adsorption process was found to follow a first order kinetics model and was not influenced by the polymer type. It was found that Freundlich model was more suitable for our data. Polyvinyl alcohol and polyvinyl pyrrolidine addition increase the adsorption capacity of the original bed due to an increment in the rigidity of the gel caused by the formation of hydrogen bound between the polysaccharides and synthetics polymers.
Assuntos
Alginatos/química , Quimotripsinogênio/química , Quimotripsinogênio/isolamento & purificação , Epicloroidrina/química , Galactanos/química , Mananas/química , Gomas Vegetais/química , Adsorção , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Cinética , Fenômenos MecânicosRESUMO
The equilibrium isotherms and adsorption kinetics of lysozyme (LZ) on epichlorohydrin (Epi) cross-linked alginate-guar gum (Alg-GG) matrix were studied. Adsorption kinetics followed a pseudo-first-order model while the equilibrium isotherm could be represented by the Freundlich equation. The maximal amount of LZ adsorbed onto this matrix was around 2.4mg per g of hydrated matrix at pH 7.00. The adsorption mechanism was associated to a simple diffusion process with a weak columbic interaction between LZ and the matrix. The presence of NaCl 0.3M induced a total displacement of the LZ from the matrix. Under this condition, the percentage of desorbed protein was 95%. Successive cycles of adsorption-washing-elution were performed and the results showed the reversibility of the process and the usefulness of the method for enzyme purification and separation. A last successful step was carried out for the purification of LZ from egg white as natural source. The model proved to be useful applied as a platform design in the isolation and purification of proteins.
Assuntos
Alginatos/química , Galactanos/química , Mananas/química , Muramidase/química , Gomas Vegetais/química , Adsorção , Animais , Clara de Ovo/química , Epicloroidrina/química , Ácido Glucurônico/química , Ácidos Hexurônicos/química , CinéticaRESUMO
The adsorption kinetics of chymotrypsin, a pancreatic serine protease, onto an alginate-gum guar matrix cross-linked with epichlorohydrin has been performed using a batch-adsorption technique. The effect of various experimental parameters such as pH, salt presence, contact time and temperature were investigated. The pseudo-first-order and pseudo-second-order kinetic models were used to describe the kinetic data which shows that the adsorption of the enzyme followed the pseudo-second-order rate expression. The Langmuir, Freundlich and Hill adsorption isotherm models were applied to describe the equilibrium isotherms, and the isotherm constants were determined. It was found that Hill model was more suitable for our data because the isotherm data showed a sigmoidal behavior with the free enzyme concentration increasing in equilibrium. At 8°C and at pH 5.0, 1g hydrate matrix adsorbed about 7mg of chymotrypsin. In the desorption process 80% of the biological activity of chymotrypsin was recovered under the condition of 50mM phosphate buffer, pH 7.00-500mM NaCl. When successive cycles of adsorption/washing/desorption were performed, it was observed that the matrix remained functional until the fourth cycle of repeated batch enzyme adsorption. These results are important in terms of diminishing of cost and waste generation.