Simultaneous On-line Monitoring of Glucose and Total Malto Sugar in Fermentation Processes Using an FIA System

Abstract

A flow injection analysis (FIA) system is presented which is able to monitor simultaneously and on-line the concentrations of glucose and total malto sugars during fermentation or hydrolysis processes. The system consists of glucoamylase (GA), glucose oxidase (GOD) EC 1.1.3.4 and mutarotase (MUT) EC 5.1.3.3 immobilized on synthetic polymer beads contained in cartridges serving as reactors. A high degree of selectivity towards non-malto sugars and carbohydrates, amino acids, and other possible components in the fermentation medium was exhibited by the system. The measurements delivered by the system during the monitoring of Bacillus licheniformis fermentation for protease production in complex media described the actual progress of the process. A correlation of the on-line measurements with the off-line enzymatic and off-line colorimetric measurements rendered correlation coefficients (r 2 ) of 0.997 and 0.995, respectively. The enzyme reactors could be used on a long-term basis at 30°C and a pH of 5.5.