Chapter 8 - Application of Biosensor in Fermentation Processes

Abstract

Publisher Summary Enzymes are generally expensive and unstable. Recently many methods have been developed for immobilization of whole cells. Sensors using immobilized whole cells and electrochemical devices have been developed. These microbial sensors can be classified into three categories: (1) microbial sensors consisting of immobilized whole cells and an oxygen electrode, (2) microbial sensors consisting of immobilized whole cells and a fuel cell type electrode, (3) microbial sensors consisting of immobilized whole cells and membrane electrodes. This chapter describes application of these microbial sensors to fermentation processes. It discusses a few microbial sensors such as glucose sensors, total assimilable sugar sensor, acetic acid sensor, alcohol sensor, sensors for cell populations, formic acid sensor, cephalosporin sensor, glutamic acid sensor, and assimilation test sensor that are used in fermentation industries. The chapter also highlights some microbial sensors used for waste waters control and their applications. All these microbial sensors appear to be quite promising for the control of fermentation processes. The advantages of these sensors are organic compounds in samples can be directly measured without any pretreatment such as filtration and dialysis, because microbial cells and colored compounds in a fermentation broth do not affect the determination, no reagent except for buffer solution is required, (microbial sensors are stable for a long time, and the microbial sensor can be readily prepared. The microbial sensors for acetic acid, ethyl alcohol, glutamic acid, cell populations, ammonia, and biochemical oxygen demand (BOD are used in industrial fermentation processes in Japan.