Enhancing Extracellular Electron Transfer of Shewanella oneidensis MR-1 through Coupling Improved Flavin Synthesis and Metal-Reducing Conduit for Pollutant Degradation

• DOI: 10.1021/acs.est.6b04640
• Publication Date: 2017-04-17T20:02:37Z
• Authors: Di Min; Lei Cheng; Feng Zhang; Xue-Na Huang; Dao-Bo Li; Dong-Feng Liu; Tai-Chu Lau; Yang Mu; Han-Qing Yu
• Keywords: Shewanella oneidensis; Shewanella; Geobacter; Electron acceptor

Dissimilatory metal reducing bacteria (DMRB) are capable of extracellular electron transfer (EET) to insoluble oxides, which used as external acceptors by DMRB for their anaerobic respiration. The EET process has important contribution environmental remediation mineral cycling, and bioelectrochemical systems. However, the low efficiency remains be one major bottlenecks its practical applications pollutant degradation. In this work, Shewanella oneidensis MR-1, a model DMRB, was examine feasibility enhancing biodegradation capacity through genetic engineering. A flavin biosynthesis gene cluster ribD-ribC-ribBA-ribE metal-reducing conduit mtrC-mtrA-mtrB were coexpressed in S. MR-1. Compared control strain, engineered strain found exhibit an improved microbial fuel cells potentiostat-controlled electrochemical cells, with increase maximum current density approximate 110% 87%, respectively. impedance spectroscopy (EIS) analysis showed that correlated lower interfacial charge-transfer resistance strain. Meanwhile, three times more rapid removal rate methyl orange confirmed improvement ability. Our results demonstrate coupling synthesis mediators conduits could efficient strategy enhance is essential remediation, wastewater treatment, bioenergy recovery from wastes.