Electrochemical Kinetic Study on the a Yeast-Catalyzed Activity in Microbial Half Cell

Microbial biofuel cells produce electricity directly from organic fuels such as glucose sucrose, acetates and ethanol. In the present work, electrochemical characteristics of the yeast-catalyzed half cell against carbon cloth electrode with various yeasts and with immobilization are investigated experimentally. Three types of yeasts as anode catalyst are employed: (1) commercially available baker’s yeast (S. Cerevisiae); (2) wild type yeast cultured in our lab; and (3) respiration-free mutant yeast. Kinetic parameters for the three types of yeasts are obtained by Tafel analysis. Cyclic voltammetry (CV) techniques are applied to investigate the reversibility of the redox reactions. Open current potential (OCP) of each yeast is measured against a reference electrode to estimate the anodic potential. Electrochemical impedance spectroscopy (EIS) of the half-cell is conducted to estimate the resistivity of the electrode and the overall ohmic resistance. This fundamental kinetic study will be used to understand the activity of the yeast as a catalyst in microbial half cell as well as fuel cell.