Immobilization of β-glucosidase on polyethersulfone membrane for cellobiose hydrolysis

Abstract

Glucosidase is one of the enzyme cocktail that is used for converting lignocellulose to glucose. The significance of glucosidase is that it converts the cellobiose to glucose and subsequently avoid product inhibition caused by cellobiose. In this work, β-glucosidase was immobilized on polyethersulfone membrane via glutardehyde crosslinking for the hydrolysis of cellobiose. Based on the peaks of FTIR spectra of the membrane, enzyme was adsorbed based on the absorbance between 3100 and 3500 cm−1. The percentage of enzyme adsorption in the membrane was 6.8 % based on the initial protein solution. Kinetic parameters of β-glucosidase of immobilized on membrane have been studied and compared with free enzyme used. The Km values for the free and immobilized gained were 166.137 g/L and 36.176 g/L respectively. The immobilized enzyme showed lower Km indicating higher affinity of substrates than free enzyme. The Vmax value obtained was 60.606 g/L h for immobilized enzyme and 136.986 g/L h for free enzyme probably due to limited access of substrates towards the immobilized enzymes. The immobilized enzyme can be reused for at least seven cycles.