ABSTRACT
A biosensor can be produced using an immobilized biocatalyst such as enzymes and fixing them onto an electrode. Many types of enzyme sensors have been developed and used in clinical analysis and fennentation control. Enzymes are generally expensive and unstable when used for fermentation and wastewater monitoring. Therefore, we have developed microbial sensors, composed of immobilized microorganisms used as recognition elements cOlnbined with an electrochemical device. These perform measurements using the assimilation capacity of microorganisms as an index of respiratory or metabolic activity. One example of this is the combination of an alcohol-assimilating microorganism (yeast) immobilized membrane and an oxygen electrode as the basis of an alcohol. Oxygen consumption can then be measured at an oxygen electrode. In this chapter we describe microbial sensors used in process and environmental control.
