STUDYING THE BIENZYME REACTION WITH AMPEROMETRIC DETECTION FOR MEASURING MALTOSE

If a fermentation process is followed by a change in the concentration of maltose, information on the level of the maltose is important. A n ew type of sensor was developed for measuring the content of maltose i n fermentation broth. The base of the sensor is a thin-layer reactor, in which a protein membrane was chosen for the immobilization of enzym es. To measure maltose, we investigated the influence of enzymes such as alpha-glucosidase (EC 3.2.1.20) and amyloglucosidase (EC 3.2.1.3) o n the effectiveness of conversion to glucose. Because amyloglucosidase proved to be more effective, a mixture of amyloglucosidase and glucos e oxidase was applied for the determination of maltose. To develop the best measuring technique, the consequences of changes in different pa rameters, such as the optimal ratio of enzymes, role of pH value and t hat of the flow rate, were studied. An amperometric measuring cell wit h Pt-Ag/AgCl-Pt electrodes was used at +600 mV operating potential. Th e results indicate that the maltose content in different types of ferm entation broth can be determined by the new measuring cell in the rang e of 0.2-4 mm maltose. The cell was successfully tested in the ferment ation of brewer's yeast.