Simultaneous Production of Bioethanol and Bioelectricity in a Membrane-Less Single-Chambered Yeast Fuel Cell by Saccharomyces cerevisiae and Pichia fermentans

Production of bioethanol and bioelectricity is a promising approach through microbial electrochemical technology. Sugars are metabolized by yeast to produces ethanol, CO2, and energy. Surplus electrons produced during the fermentation can be transferred through the circuit to generate electricity in a microbial fuel cell (MFC). In the present study, a membrane-less single-chambered microbial fuel cell was developed for simultaneous production of bioethanol and bioelectricity. Pichia fermentans along with well-known ethanol-producing yeast Saccharomyces cerevisiae were allowed to ferment glucose. S. cerevisiae demonstrated maximum open circuit voltage (OCV) 0.287 +/- 0.009 V and power density 4.473 mW m(-2) on the 15th day, with a maximum ethanol yield of 5.6% (v/v) on the 12th day. P. fermentans demonstrated a maximum OCV of 0.318 +/- 0.0039 V and power density of 8.299 mW m(-2) on 15th day with an ethanol yield of 4.7% (v/v) on 12th day. Coulombic efficiency (CE) increased gradually from 0.002-0.471% to 0.012-0.089% in the case of S. cerevisiae and P. fermentans, respectively, during 15 days of the experiment. The result indicated that single-chambered fuel cell can be explored for their potential applications for ethanol production along with clean energy generation.