On the denaturation of enzymes in the process of foam fractionation

Experimental study on the denaturation of enzyme during the separation by foaming was conducted with trypsin and catalase in aqueous medium as model system respectively. The effects of operating pH and sparging gas composition on the denaturation of an enzyme were examined respectively. The oxidative deactivation of enzyme at the gas-liquid interface was identified, which could be reduced by applying nitrogen or carbon dioxide as sparging gas. At suitable conditions, the loss of enzyme activity can be reduced to less than 10% in case of trypsin and to zero in case of catalase. With its proven mildness and effectiveness, foam fractionation in a loop bubble column is applicable for recovery and concentration of enzymes from aqueous solutions.