Discover insights from thousands of peer-reviewed papers on microbial electrochemical systems
Environmental Science and Ecotechnology · 2024
Hanna M. Fruehauf, Franziska Enzmann, Falk Harnisch et al.
Biotechnology Journal · 2020
AbstractThe objective of microbial electrosynthesis (MES) is to combine the advantages of electrochemistry and biotechnology in order to produce chemicals and fuels. This combination enables resource‐efficient processes by using renewable raw materials and regenerative energies. In the last decade, different MES processes have been described, for example, MES based on biofilms or mediators, electro‐fermentation, and secondary MES. This review compares the MES technologies with regard to the reached process performances in terms of key process indicators (i.e., coulombic efficiency (CE), product titre, productivity) and technology readiness level (TRL). Often the underlying mechanism of electron transfer in biofilm‐based processes has not been elucidated and can therefore not be optimized. Similarly, technical aspects of electro‐fermentation processes and processes with soluble mediators are under investigation and techno–economic assessments are missing. In contrast, the electrochemical production of microbial substrates in secondary MES or hybrid systems show high key process indicators and TRLs up to 7. In summary, the different types of MES processes offer options for today's industrial use, as well as an exciting and future‐oriented technology that can be applied in a medium‐term perspective.
Carlo Santoro, Sofia Babanova, Pierangela Cristiani et al.
ChemSusChem · 2021
AbstractA cross‐laboratory study on microbial fuel cells (MFC) which involved different institutions around the world is presented. The study aims to assess the development of autochthone microbial pools enriched from domestic wastewater, cultivated in identical single‐chamber MFCs, operated in the same way, thereby approaching the idea of developing common standards for MFCs. The MFCs are inoculated with domestic wastewater in different geographic locations. The acclimation stage and, consequently, the startup time are longer or shorter depending on the inoculum, but all MFCs reach similar maximum power outputs (55±22 μW cm−2) and COD removal efficiencies (87±9 %), despite the diversity of the bacterial communities. It is inferred that the MFC performance starts when the syntrophic interaction of fermentative and electrogenic bacteria stabilizes under anaerobic conditions at the anode. The generated power is mostly limited by electrolytic conductivity, electrode overpotentials, and an unbalanced external resistance. The enriched microbial consortia, although composed of different bacterial groups, share similar functions both on the anode and the cathode of the different MFCs, resulting in similar electrochemical output.
Erin M. Gaffney, Matteo Grattieri, Zayn Rhodes et al.
Journal of The Electrochemical Society · 2020
Microbial electrochemical systems offer valuable opportunities in the field of electrochemistry for a wide range of applications and fundamental insights. Applications include renewable power generation, electrosynthesis, and sensing, and provide a critical platform for understanding fundamental electrochemical processes between biotic and abiotic components. However, despite several research efforts, the fundamental electron transfer mechanisms inherent to microbial bioelectrochemical systems remain poorly understood, limiting their full potential and applications. This lack of fundamental understanding stems from both the conceptual and experimental complexity of microbial electrochemical systems. In this context, the possibility of multi-disciplinary research utilizing computational methods provides a powerful tool for this field. Herein, we critically review how computational studies and methods employed to study microbial electrochemical systems in multiple dimensions can be used to clarify the different factors governing microbial electrochemical systems. This discussion addresses how the combination of various techniques can enhance fundamental understanding, providing scientists with tools for the rational design of improved systems and opening exciting new research opportunities.
Ayush Singha Roy, Aparna Sharma, Bhim Sen Thapa et al.
Frontiers in Microbiology · 2022
In microbial electrochemical systems, microorganisms catalyze chemical reactions converting chemical energy present in organic and inorganic molecules into electrical energy. The concept of microbial electrochemistry has been gaining tremendous attention for the past two decades, mainly due to its numerous applications. This technology offers a wide range of applications in areas such as the environment, industries, and sensors. The biocatalysts governing the reactions could be cell secretion, cell component, or a whole cell. The electroactive bacteria can interact with insoluble materials such as electrodes for exchanging electrons through colonization and biofilm formation. Though biofilm formation is one of the major modes for extracellular electron transfer with the electrode, there are other few mechanisms through which the process can occur. Apart from biofilm formation electron exchange can take place through flavins, cytochromes, cell surface appendages, and other metabolites. The present article targets the various mechanisms of electron exchange for microbiome-induced electron transfer activity, proteins, and secretory molecules involved in the electron transfer. This review also focuses on various proteomics and genetics strategies implemented and developed to enhance the exo-electron transfer process in electroactive bacteria. Recent progress and reports on synthetic biology and genetic engineering in exploring the direct and indirect electron transfer phenomenon have also been emphasized.
Dena Z. Khater, R.S. Amin, M.O. Zhran et al.
Journal of Genetic Engineering and Biotechnology · 2022
Background: Although microbial fuel cells (MFCs) represent a promising technology for capturing renewable energy from wastewater, their scaling-up is significantly limited by a slow-rate cathodic oxygen reduction reaction (ORR) and the development of a resilient anodic microbial community. In this study, mixed transition metal oxides of nickel and copper (Ni and Cu), supported on a graphene (G) (NiO–CuO/G) electrocatalyst, were synthesized and tested as a cost- effective cathode for ORR in MFCs. Electrochemical measurements of electrocatalyst were conducted using a rotating disk electrode (RDE) and linear sweep voltammetry (LSV) in a neutral electrolyte, and compared with a benchmark Pt/C catalyst. Furthermore, the long-term performance of the as-synthesized electrocatalyst was evaluated in a single- chamber MFC by measuring organic matter removal and polarization behavior. The successful enrichment of electro‑ active biofilm was also monitored using transmission electron microscopy and the Vitek2 compact system technique. Results: When compared with the benchmark platinum cathode, the NiO–CuO/G electrocatalyst exhibited high selectivity toward ORR. The rotating disk electrode (RDE) experiments reveal that ORR proceeds via a 4-electron ORR mechanism. Furthermore, the NiO–CuO/G electrocatalyst also exhibited a high power density of 21.25 mW m−2 in an air-cathode MFC, which was slightly lower than that of Pt/C-based MFC (i.e., 50.4 mW m−2). Biochemical characteriza‑ tion of the most abundant bacteria on anodic biofilms identified four genera (i.e., Escherichia coli, Shewanella putrefa- ciens, Bacillus cereus, and Bacillus Thuringiensis/mycoides) that belonged to Gammaproteobacteria, and Firmicutesphyla. Conclusions: This study demonstrates that the NiO–CuO/G cathode had an enhanced electrocatalytic activity toward ORR in a pH-neutral solution. This novel mixed transition metal oxide electrocatalyst could replace expensive Pt-based catalysts for MFC applications.
Mac Link Pakistan
Journal of Environmental Science and Engineering Technology · 2021
In this study, four double-chambered Microbial fuel cells (MFCs) operated by primary effluent wastewater mixed with anaerobic sludge as substrate, was designed, built, and optimized for better higher energy production and subsequently better removal of organic matter. Optimized MFCs operating parameters as a function of energy produced include electrode material type, electrode size, salt bridge diameter, type of salt solution that used in salt bridge, and concentration of the salt solution used in the salt bridge. Three duplicates-MFCs for each parameter value were used. Output open-circuit voltage (OCV) was measured for each MFC one time daily and for one week for each tested operating parameter. Data obtained showed that (i) MFCs with copper electrodes produce output voltage significantly higher than MFCs with carbon brushes electrodes which, in turn, achieved output voltage significantly higher than both that achieved by MFCs with zinc electrodes and MFCs with manufactured carbon electrodes, (ii) MFCs with 10 mm salt bridge shown significantly higher output voltage than MFCs with both 16 and 24 mm salt bridges, (iii) KCl salt bridge in MFCs is significantly more efficient than NaCl salt bridges, and (iv) MFCs with 1M KCl salt bridges can produce output voltage significantly higher than that produced by MFCs with 3M KCl salt bridges.
Rong Xie, Shuang Wang, Kai Wang et al.
Biotechnology for Biofuels and Bioproducts · 2022
AbstractBackgroundMicrobial electricity production has received considerable attention from researchers due to its environmental friendliness and low price. The increase in the number of intracellular electrons in a microbial fuel cell (MFC) helps to improve the MFC performance.ResultsIn this study, we accumulated excess electrons intracellularly by knocking out the gene related to intracellular electron consumption inSaccharomyces cerevisiae, and the elevated intracellular electron pool positively influenced the performances of MFCs in terms of electricity production, while helping to increase ethanol production and achieve ethanol and electricity co-production, which in turn improved the utilization of substrates. The final knockout strain reached a maximum ethanol yield of 7.71 g/L and a maximum power density of 240 mW/m2in the MFC, which was 12 times higher than that of the control bacteria, with a 17.3% increase in energy utilization.ConclusionsThe knockdown of intracellular electron-consuming genes reported here allowed the accumulation of excess electrons in cells, and the elevated intracellular electron pool positively influenced the electrical production performance of the MFC. Furthermore, by knocking out the intracellular metabolic pathway, the yield of ethanol could be increased, and co-production of ethanol and electricity could be achieved. Thus, the MFC improved the utilization of the substrate.
RSC Advances · 2018
Environmental Science: Water Research & Technology · 2016
A modularized microbial fuel cell system can effectively treat primary effluent and use the produced energy to offset part of its energy consumption.
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Scientific Reports · 2018
Forest Ecology and Management · 2021
PLoS ONE · 2012
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Scientific Reports · 2023
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IEEE Access · 2022
Preprints.org · 2024
FEMS Microbiology Ecology · 2015
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AMB Express · 2019
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Joule · 2020
Renewable and Sustainable Energy Reviews · 2015
Biosensors · 2022
Nanoscale · 2018
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Joule · 2020
PLoS ONE · 2012
The ISME Journal · 2014