Analysis of adsorption function of polyhydroxybutyrate depolymerase from Alcaligenes faecalis T1 by using a quartz crystal microbalance

Enzymatic adsorption and degradation of three types of aliphatic polyester films and two types of polyolefin films by the extracellular PHB depolymera se from Alcaligenes faecalis T1 have been studied by using a quartz crystal microbalance (QCM) technique. Hydrolysis of poly[(R)-3-hydroxybutyrate] wa s quantitatively followed by the QCM technique. Adsorption of the enzymes t o films was also quantitatively detected by the QCM. Kinetic study on enzym atic adsorption suggests that the PHB depolymerase binds to the substrates not only by hydrophobic interaction but also by specific interaction betwee n the ester bonds of polyesters and the binding domain of the enzyme. The r esults show that the QCM technique is a sensitive tool to study enzymatic d egradation kinetics of biodegradable polyesters.