Ultra-rapid fluorescence assay for cellulase using a substrate-immobilized mini-bioreactor

Abstract

A simple, ultra-rapid assay method has been developed for the determination of cellulase activity. The method is based of fluorescence detection following flow injection into a mini-bioreactor containing Lucifer Yellow-labelled cellulose. Cellulase activity is determined by measuring the intensity of the fluorescent fragments released from the bioreactor after the injection of the enzyme solution. The assay is fast, with a response time of less than 30 s. The fluorescence signal obtained is reproducible (s_r= 6.1%, n= 9) and linear within the measured range (1–20 µg of crude enzyme of activity 10 units per milligram; n= 5, r²= 0.997).