A new study of the enzymatic hydrolysis of carboxymethyl cellulose with a bulk acoustic wave sensor

A new bulk acoustic wave (BAW) cellulase sensing technique, which is based on the enzymatic hydrolysis process of sodium carboxymethylcellulose (CMC) by cellulase, was established. The frequency shift curves of BAW sensor ind icated that the viscosity of the tested solutions decreased during the hydr olysis process. The hydrolysis rate of CMC by cellulase was calculated from the frequency shift curves. The hydrolysis rate of CMC under different pH conditions at 30 degrees C showed that cellulase had high hydrolysis abilit y approximately at pH 5.0. Kinetic parameters (the Michaelis constant K-m a nd the maximum rate V-max) of the process were estimated by using a linear method of Lineweaver-Burk plot. K-max is 1.95 +/- 0.25 mg ml (- 1) and V-ma x is - (4.25 +/- 0.58) x 10 (- 3) g(1/2) cm (- 3/2) cP(1/2) min (-1). Also the activation energy (E-a) of the enzymatic hydrolysis, with a value of 51 .99 +/- 1.26 kJ mol(-1), was estimated in this work. (C) 2000 Elsevier Scie nce B.V. All rights reserved.