Abstract: An assay is described for cellobiase (β-glucosidase) activity of the Trichoderma reesei CCF 1853 cellulase complex. Analysis was performed using a flow-mix system coupled with a free standing multichannel microcalorimeter. Sample solution was merged with a stream of 5 mM citrate buffer solution of pH 5 in the flow-mix cell, before passing through the measuring cell. Once a stable baseline was obtained , the clean buffer solution was changed step by step for solution with different concentrations of cellobiose or cellobiose and glucose. The heat generated by the enzymatic reaction and other side reactions was recorded in the measuring cell and the signal was corrected by the subtraction of the individual dilution heat flows of cellobiose and glucose, the interaction heat flows of cellobiose and glucose and the interaction heat flows of glucose and sample solution The flow rate was 55 mL/h and the residence time was 40 s. The method allowed the determination of cellobiase activity or cellobiose concentration with a detection limit of 10 µM-cellobiose. Results are discussed.

Abstract: Glucose was determined by flow injection spectrophotometry using an automated flow analyzer. (cf. Analyst, 1990, 115, 65) and the Merckotest kit (Merck) which is based on the glucose oxidase - peroxidase reaction. Water was used as the carrier stream and detection was carried out at 510 nm. The mean coefficient of variation was 0.76% and a sample throughput of >80 h-1 was achieved. The analyzer. demonstrated linearity of >0.9997 for five consecutive sets of standards. The effects of temp., divalent ion concentration and pH on the kinetics of β-galactosidase cleavage of a novel substrate, VLMgal, were also investigated using a single-line manifold. Results are discussed.