Electricity production and microbial biofilm characterization in cellulose-fed microbial fuel cells

Converting biodegradable materials into electricity, microbial fuel cells (MFCs) present a promising technology for renewable energy production in specific applications. Unlike typical soluble substrates that have been used as electron donors in MFC studies, cellulose is unique because it requires a microbial consortium that can metabolize both an insoluble electron donor (cellulose) and electron acceptor (electrode). In this study, electricity generation and the microbial ecology of cellulose-fed MFCs were analyzed using a defined co-culture of Clostridium cellulolyticum and Geobacter sulfurreducens. Fluorescent in situ hybridization and quantitative PCR showed that when particulate MN301 cellulose was used as sole substrate, most Clostridium cells were found adhered to cellulose particles in suspension, while most Geobacter cells were attached to the electrode. By comparison, both bacteria resided in suspension and biofilm samples when soluble carboxymethyl cellulose was used. This distinct function-related distribution of the bacteria suggests an opportunity to optimize reactor operation by settling cellulose and decanting supernatant to extend cellulose hydrolysis and improve cellulose-electricity conversion.

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Bioremediation of Pollutants and Sustainable Energy Production through Bacterial Activities in Microbial Fuel Cells: An Overview

Asian Journal of Chemistry ◽

10.14233/ajchem.2021.23081 ◽

2021 ◽

Vol 33 (2) ◽

pp. 253-265

Author(s):

ROZINA KAKAR ◽

AMIRUL-AL-ASHRAF ABDULLAH ◽

MOHD RASHID ◽

RABIA TASADUQ HUSSAIN ◽

AMIRA SURIATY YAAKOP ◽

...

Keyword(s):

Heavy Metals ◽

Fuel Cells ◽

Microbial Fuel Cells ◽

Energy Production ◽

Electrical Energy ◽

Electricity Production ◽

Organic Substrates ◽

Electron Transfer Mechanism ◽

Removal Of Heavy Metals ◽

Sustainable Electricity

Electrical energy generation can be achieved in microbial fuel cells (MFCs) through the catalytic action of microorganisms which can oxidize organic matter and convert it into a biofilm. In MFCs, the exoelectrogens play a crucial role. MFCs is eco-friendly promising technology that produces electricity from various organic substrates. It is a novel and environmentally friendly approach for bioremediation and sustainable electricity production. The fact that heavy metals contributing adversely to the environmental pollution thus the microbial fuel cell technology has a solution for this as well, performing the removal and recovery of heavy metals by using both single and doublechambered MFCs. Many studies show that the new strains of microbes can produce power densities individually as high as strains from mixed communities. However, the implementation of this technology is just limited to the laboratory scale because of a few challenges like low efficiencies, low production rates. This review article focuses an introduction about the role and mechanism of different microorganisms towards energy production, biofilm formation, high power producing microbes inside the microorganisms, the electron transfer mechanism to the electrodes and vice-versa and the removal of heavy metals.

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Electricity Production by Geobacter sulfurreducens Attached to Electrodes

Applied and Environmental Microbiology ◽

10.1128/aem.69.3.1548-1555.2003 ◽

2003 ◽

Vol 69 (3) ◽

pp. 1548-1555 ◽

Cited By ~ 1347

Author(s):

Daniel R. Bond ◽

Derek R. Lovley

Keyword(s):

Electron Transfer ◽

Fuel Cells ◽

Electron Donor ◽

Electron Acceptor ◽

Microbial Fuel Cells ◽

Electrical Current ◽

Geobacter Sulfurreducens ◽

Electricity Production ◽

Organic Substrates ◽

Current Production

ABSTRACT Previous studies have suggested that members of the Geobacteraceae can use electrodes as electron acceptors for anaerobic respiration. In order to better understand this electron transfer process for energy production, Geobacter sulfurreducens was inoculated into chambers in which a graphite electrode served as the sole electron acceptor and acetate or hydrogen was the electron donor. The electron-accepting electrodes were maintained at oxidizing potentials by connecting them to similar electrodes in oxygenated medium (fuel cells) or to potentiostats that poised electrodes at +0.2 V versus an Ag/AgCl reference electrode (poised potential). When a small inoculum of G. sulfurreducens was introduced into electrode-containing chambers, electrical current production was dependent upon oxidation of acetate to carbon dioxide and increased exponentially, indicating for the first time that electrode reduction supported the growth of this organism. When the medium was replaced with an anaerobic buffer lacking nutrients required for growth, acetate-dependent electrical current production was unaffected and cells attached to these electrodes continued to generate electrical current for weeks. This represents the first report of microbial electricity production solely by cells attached to an electrode. Electrode-attached cells completely oxidized acetate to levels below detection (<10 μM), and hydrogen was metabolized to a threshold of 3 Pa. The rates of electron transfer to electrodes (0.21 to 1.2 μmol of electrons/mg of protein/min) were similar to those observed for respiration with Fe(III) citrate as the electron acceptor (Eo′ =+0.37 V). The production of current in microbial fuel cell (65 mA/m2 of electrode surface) or poised-potential (163 to 1,143 mA/m2) mode was greater than what has been reported for other microbial systems, even those that employed higher cell densities and electron-shuttling compounds. Since acetate was completely oxidized, the efficiency of conversion of organic electron donor to electricity was significantly higher than in previously described microbial fuel cells. These results suggest that the effectiveness of microbial fuel cells can be increased with organisms such as G. sulfurreducens that can attach to electrodes and remain viable for long periods of time while completely oxidizing organic substrates with quantitative transfer of electrons to an electrode.

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Microbial fuel cells: Devices for real wastewater treatment, rather than electricity production

The Science of The Total Environment ◽

10.1016/j.scitotenv.2021.145904 ◽

2021 ◽

Vol 775 ◽

pp. 145904

Author(s):

Jaecheul Yu ◽

Younghyun Park ◽

Evy Widyaningsih ◽

Sunah Kim ◽

Younggy Kim ◽

...

Keyword(s):

Wastewater Treatment ◽

Fuel Cells ◽

Microbial Fuel Cells ◽

Electricity Production ◽

Real Wastewater

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The high enrichment of Geobacter by TiN nanoarray anode catalyst for efficient microbial fuel cells

Journal of Materials Chemistry A ◽

10.1039/d0ta11788a ◽

2021 ◽

Vol 9 (12) ◽

pp. 7726-7735

Author(s):

Da Liu ◽

Weicheng Huang ◽

Qinghuan Chang ◽

Lu Zhang ◽

Ruiwen Wang ◽

...

Keyword(s):

Fuel Cells ◽

Hierarchical Structure ◽

Microbial Fuel Cells ◽

Dft Calculation ◽

Experimental Results ◽

Carbon Cloth ◽

Anode Catalyst ◽

High Enrichment

TiN nanoarrays, in situ grown on carbon cloth gather 97.2% of the model exoelectrogen Geobacter, greatly enhancing the MFCs' performance. The experimental results and DFT calculation certify the importance of the micro–nano-hierarchical structure.

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