The adsorption of glucoamylases I and II (GA I and GA II, respectively) from Aspergillus niger on the anion exchanger DEAE-Toyopearl 650 was studied in fixed-bed experiments, and the effect of temperature, flowrate, inlet concentration, bed length, and particle size on the process was characterized. The anion exchanger showed a higher adsorption capacity for the more active isoenzyme GA I in all experimental conditions studied. A mathematical model accounting for external and pore diffusion and nonlinear equilibrium isotherm (for GA I) was used to fit the experimental breakthrough curves, showing very accurate fittings in all of the operating conditions. The values of the pore diffusion coefficient at 15, 20, and 25 degrees C were, respectively, 1.25 x 10(-)(11), 1.46 x 10(-)(11) and 1.83 x 10(-)(11) (for GA I) and 1.82 x 10(-)(11), 2.44 x 10(-)(11) and 2.73 x 10(-)(11) (for GA II) m(2)/s. Bicomponent adsorption experiments showed no significant interference effects between GA I and GA II, and so the mathematical model was again used to fit these experiments, yielding very satisfactory results.
Purification of high added value products obtained by fermentation processes is a key research task in current biotechnology, especially the ones concerning proteins of very similar molecular structure such as isoenzymes. Purification and separation of biomolecules by commercial ion exchangers is an attractive alternative to affinity chromatography due to its availability and lower cost. For this reason and for its high uptake capacity there is an increasing interest in the application of ion exchangers in biotechnological downstream processing.In this paper, the kinetics of ion exchange of the two isoenzymes of glucoamylase from Aspergillus niger on the anion exchanger DEAE-Toyopearl 650 have been investigated in a batch stirred tank. The experimental results were fitted to a mathematical model accounting for both external fluid film mass 61
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.