Isolation and characterization of an electricity-producing strain Nitratireductor sp. WJ5-4

Abstract:

[Objective] To isolate and obtain an electrochemically bacterium (exoelectrogen), strain WJ5-4, from anode leacheate of MFC using biowaste as substrate and to study its electrical characteristics. [Methods] The strain was identified by morphological observation, physiological and biochemical properties and 16S rDNA sequence analysis. MFC (microbial fuel cell) was constructed using strain WJ5-4 as exoelectrogen and using biowaste as substrate. The electrical properties of strain WJ5-4 was studied on different inoculation concentration and solid content. [Results] The strain WJ5-4 belonged to Nitratireductor, when inoculation concentration was 200 mL, the maximum power density was 135.16 mW/m2, stable working voltage was 370 mV and degradation of TOC (total organic carbon) was up to 41.46%. When solid content was 23%, power density was 163.69 mW/m2, the voltage was 434 mV, and degradation of TOC was up to 46.29%. [Conclusion] Strain WJ5-4 could produce electricity using higher solid content biowaste, and the electricity production cycle was longer. These results would provide reliable basis for further treatment of biowaste by the means of MFC.