Bioelectrocatalysis, powerful means of connecting electrochemistry to biochemistry and biotechnology

Abstract

Fundamental and applied aspects of bioelectrochemistry have been considered by placing emphasis on bioelectrocatalysis, a key reaction allowing electrochemical measurements and controls of oxidoreductase reactions. Recent investigations in the authors' laboratory on this subject will be reviewed. Mediated bioelectrocatalysis is the enzyme-electrochemical reaction with an electrochemical regeneration of an electron acceptor (or donor) of the enzyme. We developed new methods of kinetic and redox potential measurements in oxidoreductase reactions based on mediated bioelectrocatalysis, which proved to be powerful tools in fundamental research on biochemistry. Physicochemical properties of a new enzyme discovered by us are studied using these techniques. Bacterial catalytic activity has also been measured by the present methods. In applied aspects, mediated bioelectrocatalysis is the working principle of a variety of amperometric biosensors, some of which are now in practical use and are commercially available. We discuss fundamental aspects of the amperometric biosensor and mention its novel applications in the fields of microbiology and food science. Studies of biofuel cells are a rapidly growing field and have received great attention very recently. A biofuel cell relying upon mediated bioelectrocatalysis is described, which operates under ambient temperature and at neutral pH.