Isolation of two iron-reducing facultative anaerobic electricigens and probing the application performance in eutrophication water

Purpose Sediment microbial fuel cell (SMFC) is a promising bioremediation technology in which microbes play an important role. Electricigens as the bio-catalysts have effect on pollution control and electricity generation. It is of great significance to screen the microorganisms with the ability of generating electricity. Methods The SMFC anode biofilm was used as microbiological source to study the feasibility of electricigens with iron-reducing property for eutrophication water treatment. Preliminarily, we isolated 20 facultative anaerobic pure bacteria and evaluated their cyclic voltammogram (CV) through the three-electrode system and electrochemical workstation. The power generation performance of strains was verified by air-cathode microbial fuel cells (AC-MFCs) under different single carbon sources. Result According to its morphological, physiological, and biochemical characteristics, along with phylogenetic analysis, the two strains (SMFC-7 and SMFC-17) with electrical characteristics were identified as Bacillus cereus. Compared with SMFC-7, SMFC-17 exhibited efficient NH4+-N and NO3--N removal and PO43--P accumulation from eutrophic solution with a removal rate of 79.91 +/- 6.34% and 81.26 +/- 1.11% and accumulation rate of 57.68 +/- 4.36%, respectively. Conclusion The isolated bacteria SMFC-17 showed a good performance in eutrophic solution, and it might be a useful biocatalyst to enable the industrialized application of SMFC in eutrophic water treatment.