Determination by the enzyme thermistor of cellobiose formed on degradation of cellulose

Abstract

A calorimetric assay procedure for the determination of cellobiose has been developed. The cellobiose is hydrolyzed by β-glucosidase and the glucose formed is measured calorimetrically by an enzyme thermistor containing co-immobilized glucose oxidase and catalase. The system was optimized with regard to the arrangement of the enzymes, the pH-dependence of the separate enzymic steps, and of the total system. By placing the β-glucosidase in a precolumn that could be switched in and out of the flow through the enzyme thermistor, both cellobiose and glucose present in the sample could be determined. The performance with standard solutions and with crude samples from cellulose degradation experiments was investigated.