Biosurfactant Production from Used Vegetable Oil in the Anode Chamber of a Microbial Electrosynthesizing Fuel Cell

In this study, producing biosurfactant from used vegetable oil in the anode chamber of a microbial electrosynthesizing fuel cell (MEFC) with electrical energy production was investigated. Up to 10 mL/L used vegetable oil was used with an acclimated bacterial culture—Serratia sp. in the anode chamber. The biosurfactant production and bacterial growth in the anode chamber was compared to a continuously stirred batch reactor of comparable size. Up to 3.05 g/L of biosurfactant was produced in the anode solution and a reduction of surface tension to 25.2 mN/m was reached after 7 days of the MEFC operation. At the same time, a maximum power density of 1.13 mW/m2 was produced. The MEFC was further characterized using the electrochemical impedance spectroscopy. Mathematical expression was established to model the total impedance of the MEFC. The production of the biosurfactant from the used vegetable oil waste in the anode chamber and also producing electric power makes the MEFC multifunctional.