Enhancement of bioelectricity generation by cofactor manipulation in microbial fuel cell.
Microbial fuel cells (MFCs) are promising for harnessing bioenergy from various organic wastes. However, low electricity power output (EPT) is one of the major bottlenecks in the practical application of MFCs. In this study, EPT improvement by cofactor manipulation was explored in the Pseudomonas aeruginosa-inoculated MFCs. By overexpression of nadE (NAD synthetase gene), the availability of the intracellular cofactor pool (NAD(H/(+))) significantly increased, and delivered approximately three times higher power output than the original strain (increased from 10.86 μW/cm(2) to 40.13 μW/cm(2)). The nadE overexpression strain showed about a onefold decrease in charge transfer resistance and higher electrochemical activity than the original strain, which should underlie the power output improvement. Furthermore, cyclic voltammetry, HPLC, and LC-MS analysis showed that the concentration of the electron shuttle (pyocyanin) increased approximately 1.5 fold upon nadE overexpression, which was responsible for the enhanced electrochemical activity. Thus, the results substantiated that the manipulation of intracellular cofactor could be an efficient approach to improve the EPT of MFCs, and implied metabolic engineering is of great potential for EPT improvement.
College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, China; Bioenergy Research Institute, Nanjing University of Technology, Nanjing 210009, China.
Xiao-Yu
XY
Yong
College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, China.
Jiao
J
Feng
College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, China.
Yi-Lu
YL
Chen
College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, China.
Dong-Yan
DY
Shi
College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, China.
Yu-Shang
YS
Xu
College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, China; Bioenergy Research Institute, Nanjing University of Technology, Nanjing 210009, China.
Jun
J
Zhou
College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, China; Bioenergy Research Institute, Nanjing University of Technology, Nanjing 210009, China.
Shu-Ya
SY
Wang
College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, China.
Lin
L
Xu
Biofuels Institute, School of the Environment, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, China.
Yang-Chun
YC
Yong
Guangzhou Institute of Energy Conversion, Key Laboratory of Renewable Energy, Chinese Academy of Sciences, Guangzhou 510640, China.
Yong-Ming
YM
Sun
Guangdong Institute of Eco-environment and Soli Science, Guangzhou 510650, China.
Chen-Lu
CL
Shi
College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, China; Bioenergy Research Institute, Nanjing University of Technology, Nanjing 210009, China.
Ping-Kai
PK
OuYang
College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, China; Bioenergy Research Institute, Nanjing University of Technology, Nanjing 210009, China. Electronic address: hellozheng@gmail.com.
Tao
T
Zheng
D019732:Amide Synthases / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001674:Bioelectric Energy Sources / Q000382:microbiology*; D004560:Electricity; D055664:Electrochemical Techniques; D060847:Metabolic Engineering; D009243:NAD / Q000378:metabolism; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000502:physiology*; D015854:Up-Regulation
D001426:Bacterial Proteins; D009243:NAD; D019732:Amide Synthases; C038479:NAD+ synthase
Metabolic engineering; Microbial fuel cell; NAD synthetase; NADH/NAD(+); Pseudomonas aeruginosa