• Journal of Microbiology and Biotechnology
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• v.33 no.5
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• pp.687-697
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• 2023

Identification of novel, electricity-producing bacteria has garnered remarkable interest because of the various applications of electricigens in microbial fuel cell and bioelectrochemical systems. Shewanella marisflavi BBL25, an electricity-generating microorganism, uses various carbon sources and shows broader sugar utilization than the better-known S. oneidensis MR-1. To determine the sugar-utilizing genes and electricity production and transfer system in S. marisflavi BBL25, we performed an in-depth analysis using whole-genome sequencing. We identified various genes associated with carbon source utilization and the electron transfer system, similar to those of S. oneidensis MR-1. In addition, we identified genes related to hydrogen production systems in S. marisflavi BBL25, which were different from those in S. oneidensis MR-1. When we cultured S. marisflavi BBL25 under anaerobic conditions, the strain produced 427.58 ± 5.85 µl of biohydrogen from pyruvate and 877.43 ± 28.53 µl from xylose. As S. oneidensis MR-1 could not utilize glucose well, we introduced the glk gene from S. marisflavi BBL25 into S. oneidensis MR-1, resulting in a 117.35% increase in growth and a 17.64% increase in glucose consumption. The results of S. marisflavi BBL25 genome sequencing aided in the understanding of sugar utilization, electron transfer systems, and hydrogen production systems in other Shewanella species.

• Journal of Microbiology and Biotechnology
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• v.19 no.9
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• pp.1019-1027
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• 2009

A noncompartmented microbial fuel cell (NCMFC) composed of a Mn(IV)-carbon plate and a Fe(III)-carbon plate was used for electricity generation from organic wastewater without consumption of external energy. The Fe(III)-carbon plate, coated with a porous ceramic membrane and a semipermeable cellulose acetate film, was used as a cathode, which substituted for the catholyte and cathode. The Mn(IV)-carbon plate was used as an anode without a membrane or film coating. A solar cell connected to the NCMFC activated electricity generation and bacterial consumption of organic matter contained in the wastewater. More than 99% of the organic matter was biochemically oxidized during wastewater flow through the four NCMFC units. A predominant bacterium isolated from the anode surface in both the conventional and the solar cell-linked NCMFC was found to be more than 99% similar to a Mn(II)-oxidizing bacterium and Burkeholderia sp., based on 16S rDNA sequence analysis. The isolate reacted electrochemically with the Mn(IV)-modified anode and produced electricity in the NCMFC. After 90 days of incubation, a bacterial species that was enriched on the Mn(IV)-modified anode surface in all of the NCMFC units was found to be very similar to the initially isolated predominant species by comparing 16S rDNA sequences.

• Journal of Microbiology and Biotechnology
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• v.14 no.3
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• pp.540-546
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• 2004

We deviced a new graphite-Mn(II) electrode and found that the modified electrode with Mn(II) can catalyze NADH oxidation and $NAD^+$ reduction coupled to electricity production and consumption as oxidizing agent and reducing power, respectively. In fuel cell with graphite-Mn(II) anode and graphite-Fe(III) cathode, the electricity of 1.5 coulomb (A x s) was produced from NADH which was electrochemically reduced by the graphite-Mn(II) electrode. When the initial concentrations of pyruvate and acetaldehyde were adjusted to 40 mM and 200 mM, respectively, about 25 mM lactate and 35 mM ethanol were produced from 40 mM pyruvate and 200 mM acetaldehyde, respectively, by catalysis of ADH and LDH in the electrochemical reactor with $NAD^+$ as cofactor and electricity as reducing power. By using this new electrode with catalytic function, the bioelectrocatalysts are engineered; namely, oxidoreductase (e.g., lactate dehydrogenase) and $NAD^+$ can function for biotransformation without electron mediator and second oxidoreductase for $NAD^+$/NADH recycling.

• Korean Journal of Environmental Agriculture
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• v.26 no.2
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• pp.179-185
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• 2007

A new technology that utilizes a microbial fuel cell (MFC) has been developed to generate electricity directly from the oxidation of organic matters such as carbohydrates or complex organics in wastewater. Fermentation of these organic matters results in production of volatile fatty acids (VFAs), alcohols, $CO_2$ and $H_2$. We investigated the electricity-producing potential of the VFAs and actual food processing wastewater using a two-chambered MFC. The electrons produced by acetate degradation were proportional to acetate concentration in the medium. Acetate concentration and generated power were linearly correlated at a low range or acetate concentration (< 8 mg/L), but at above 8 mg/L of acetate the power produced was maintained at 0.1 mW. When butyrate was added to the anode acclimated to acetate, there was a lag period of 30 hr for electricity generation. However, when propionate was added to the same anode bottle, lag periods were not existed. The wastewater from baby food processing generated the maximum power density of $81{\pm}7\;mW/m^2$ of electricity and exhibited the Coulombic efficiencies of 27.1% and 40.5% based on TCOD and SCOD, respectively. Sugars in the food processing wastewater were reduced within 50 h from 230 mg/L < 30 mg/L.

• Journal of Microbiology and Biotechnology
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• v.15 no.2
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• pp.281-286
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• 2005

We created a new graphite-Cu(II) electrode and found that the electrode could catalyze FADH$_2$ oxidation and FAD reduction coupled to electricity production and consumption, respectively. In a fuel cell with graphite-Cu(II) anode and graphite-Fe(III) cathode, the electricity was produced by coupling to the spontaneous oxidation of FADH$_2$ Fumarate and xylose were not produced from the enzymatic oxidation of succinate and xylitol without FAD, respectively, but produced with FAD. The production of fumarate and xylose in the reactor with FAD electrochemically regenerated was maximally 2- 5 times higher than that in the reactor with FAD. By using this new electrode with catalytic function, a bioelectrocatalysts can be engineered; namely, oxidoreductase (e.g., lactate dehydrogenase) and FAD can function for biotransformation without an electron mediator and second oxidoreductase for cofactors recycling.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.410-420
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• 2012

The heavy reliance on fossil fuels, especially oil and gas has triggered the global energy crisis. Continued use of petroleum fuels is now widely recognized as unsustainable because of their depleting supplies and degradation to the environment. To become less dependent on fossil fuels, current world is shifting paradigm in energy by developing alternative energy sources mainly through the utilization of renewable energy sources. In particular, bioenergy recovery from wastes with the help of microorganism is viewed as one of the promising ways to mitigate the current global warming crisis as well as to supply global energy. It has been proved that microorganism can generate power by converting organic matter into electricity using microbial fuel cells (MFCs). MFC is a bioelectrochemical device that employs microbes to generate electricity from bio-convertible substrate such as wastewaters including municipal solid waste, industrial, agriculture wastes, and sewage. Sustainability, carbon neutral and generation of renewable energy are some of the major features of MFCs. However, the MFC technology is confronted with a number of issues and challenges such as low power production, high electrode material cost and so on. This paper reviews the recent developments in MFC technology with due consideration of electrode materials used in MFCs. In addition, application of biocathodes in MFCs has been discussed.

• The KSFM Journal of Fluid Machinery
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• v.18 no.6
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• pp.27-30
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• 2015

In this study, we attempted to harvest energy using water droplet based on Reverse Electro Wetting On Dielectric (REWOD) phenomenon between water droplet and dielectric surface without external bias. REWOD device can be fabricated via simple coating process, which is highly economic and easy. We believe that our system is well-suited for IoT(Internet of Things) embedded electronics that require low but consistent electricity. Moreover, our device can be integrated with window to generate electricity upon raindrops.

• Proceedings of the Microbiological Society of Korea Conference
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• 2000.10a
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• pp.92-99
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• 2000

In this study biofuel cell is classified into 5 generation fuel cell system based on structural and structural difference. I optionally named the biofuel cell with electron mediators prototype, that with electrochemical active bacterium 2nd generation, that with modified electrode with NR 3rd generation, that with catalytic active electrode 4th generation, and that using air as a catholyte instead of ion selective membrane and cathode, respectively. The electricity production was compared among 5 types biofuel cell and was confirmed to be $50-100\%$ higher in 4th and 5th generation than in 1st to 3rd generation.

• Applied Chemistry for Engineering
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• v.23 no.3
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• pp.297-301
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• 2012

Microbial fuel cell (MFC) is the major of bio-electrochemical system which can convert biomass spontaneously into electricity through the metabolic activity of the microorganisms. In this study, we used an activated sludge as a microbial inoculum and then investigated the feasibility of using dairy wastewater as a possible substrate for generating electricity in MFC. To examine the performance of MFC as power generator, the characteristics on cell potentials, power density, cyclic voltammetric analysis and sustainable power estimation were evaluated for dairy wastewater. The maximum power density of $40\;mW/m^2$was achieved when the dairy wastewater containing 2650 mg/L COD was used, leading to the removal of 88% of the COD. The results from this study demonstrate the feasibility of using MFC technology to generate electricity while simultaneously treating dairy wastewater effectively.

• Corrosion Science and Technology
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• v.7 no.1
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• pp.27-34
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• 2008

In industrial and fluid handling systems, frequently the protective film forming materials suffer from severe corrosion due to microbial effects. As an example, various micro-organisms, including bacteria, exist in seawater normally fed to power and desalination plants. Unless seawater intakes are properly disinfected to control these microbial organisms, biological fouling and microbial induced corrosion (MIC) will be developed. This problem could destroy metallic alloys used for plant construction. Seawater intakes of cogeneration plants are usually disinfected by chlorine gas or sodium hypochlorite solution. The dose of disinfectant is designed according to the level of contamination of the open seawater in the vicinity of the plant intake. Higher temperature levels, lower pH, reduced flow velocity and oxidation potential play an important role in the enhancement of microbial induced corrosion and bio-fouling. This paper describes, in brief, the different types of bacteria, mechanisms of microbiological induced corrosion, susceptibility of different metal alloys to MIC and possible solutions for mitigating this problem in industry. A case study is presented for the power plant steam condenser at Al-Taweelah B-station in Abu Dhabi. The study demonstrates resistance of Titanium tubes to MIC.