Operational Stability of Glucoamylase in Continuously Operated Ultrafiltration Membrane Reactor - Experimental Methods and Mathematical Model

摘要

Operational stability of glucoamylase was studied at 45, 60 and 70 degrees C in the reaction of maltose hydrolysis. The experiments were carried out in a continuously operated ultrafiltration membrane reactor (UFMR) at constant residence time of 176.5 minutes. The rate of enzyme operational stability decay increased with temperature. This could be quantitatively observed from the measurements of volume activity during the experiments, which were used to estimate enzyme operational stability decay rate constants. The results have shown that stationary conditions in UFMR can be maintained if sufficiently high enzyme concentration is used in the reactor, regardless of the enzyme operational stability decay that occurs. This was shown by the experiment carried out at 45 degrees C where it was proved that the enzyme operational decay occurs even though maltose conversion was at maximum during the entire experiment. Thus, the operational stability decay can be masked.