• Journal of Microbiology and Biotechnology
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• 제17권1호
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• pp.110-115
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• 2007

Electrochemically active bacteria were successfully enriched in an electrochemical cell using a positively poised working electrode. The positively poised working electrode (+0.7 V vs. Ag/AgCl) was used as an electron acceptor for enrichment and growth of electrochemically active bacteria. When activated sludge and synthetic wastewater were fed to the electrochemical cell, a gradual increase in amperometric current was observed. After a period of time in which the amperometric current was stabilized (generally 8 days), linear correlations between the amperometric signals from the electrochemical cell and added BOD (biochemical oxygen demand) concentrations were established. Cyclic voltammetry of the enriched electrode also showed prominent electrochemical activity. When the enriched electrodes were examined with electron microscopy and confocal scanning laser microscopy, a biofilm on the enriched electrode surface and bacterium-like particles were observed. These experimental results indicate that the electrochemical system in this study is a useful tool for the enrichment of an electrochemically active bacterial consortium and could be used as a novel microbial biosensor.

• Journal of Microbiology and Biotechnology
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• 제16권9호
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• pp.1481-1484
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• 2006

In this study, glucose and glutamate (copiotrophic conditions) were used to enrich electrochemically active bacteria (EAB) in a microbial fuel cell (MFC). The enriched population consisted primarily of ${\gamma}$-Proteobacteria (36.5%), followed by Firmicutes (27%) and O-Proteobacteria (15%). Accordingly, we compared our own enrichments done under many different conditions with those reported from the literature, all of which support the notion that electrochemically active bacteria are taxonomically very diverse. Enrichments with different types and levels of energy sources (fuels) have clearly yielded many different groups of bacteria.

• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2592-2596
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• 2012

Cysteine capped silver nanoparticles (Cys-AgNPs) have been synthesized by employing electrochemically active biofilm (EAB), $AgNO_3$ as precursor and sodium acetate as electron donor in aqueous solution at $30^{\circ}C$. Cys-AgNPs of 5-10 nm were synthesized and characterized by UV-Vis, FT-IR, XRD and TEM. Capping of the silver nanoparticles with cysteine provides stability to nanoparticles by a thiolate bond between the amino acid and the nanoparticle surface and hydrogen bonding among the Cys-AgNPs. In addition, the antibacterial effects of as-synthesized Cys-AgNPs have been tested against two pathogenic bacteria Escherichia coli (O157:H7) and Pseudomonas aeruginosa (PAO1). The results demonstrate that the as-synthesized Cys-AgNPs can proficiently inhibit the growth and multiplication of E. coli and P. aeruginosa.

• 한국환경보건학회지
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• 제38권2호
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• pp.83-94
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• 2012

The research on microbial fuel cells (MFCs) needs various knowledge of different fields such as electrochemistry, microbiology, environmental engineering, and material engineering. Although electrochemically active bacteria are very diverse, the performance of MFCs is affected primarily by the structure of the reactor system. Thus, the development in the system architecture is critical to lower internal resistance and increase power generation for commercialization. This paper summarizes the principles of MFCs and demonstrates the infinite potential of MFCs in various applications including wastewater treatment, biosensors, biohydrogen production, remote power sources, implantable medical devices, etc.

• Journal of Microbiology and Biotechnology
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• 제21권2호
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• pp.187-191
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• 2011

Microbial fuel cells (MFCs) were successfully enriched using sludge contaminated with Cr(VI) and their characteristics were investigated. After enrichment, the charge of the final 10 peaks was 0.51 C ${\pm}$ 1.16%, and the anodic electrode was found to be covered with a biofilm. The enriched MFCs removed 93% of 5 mg/l Cr(VI) and 61% of 25 mg/l Cr(VI). 16S rDNA DGGE profiles from the anodic electrode indicated that ${\beta}$-Proteobacteria, Actinobacteria, and Acinetobacter sp. dominated. This study is the first to report that electrochemically active and Cr(VI)-reducing bacteria could be enriched in the anode compartment of MFCs using Cr(VI)-containing sludge and demonstrates the Cr(VI) removal capability of such MFCs.

• 한국물환경학회지
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• 제26권4호
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• pp.608-613
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• 2010

Electricity generation of microbial fuel cells (MFC) is greatly affected by the kind of feed substrates because substrates would change microbial community of electrochemically active bacteria (EAB) able to transfer electrons to electrode. The effect of different substrates on electricity generation and microbial community of MFC was investigated. Two-chamber MFCs fed with acetate (A-MFC), butyrate (B-MFC), propionate (P-MFC), glucose (G-MFC) and a mixture (M-MFC) of the 4 substrates (acetate : butyrate : propionate : glucose = 1 : 1 : 1 : 1 as $COD_{Cr}$ base) were operated under continuous mode. The maximum power density was found from the M-MFC ($190W/m^3$) which showed the lowest internal resistance ($89{\Omega}$). The maximum power densities of the pure substrates feed MFCs were in order of A-MFC ($25W/m^3$), P-MFC ($21W/m^3$), B-MFC ($20W/m^3$) and G-MFC ($9W/m^3$). In DGGE analysis, the microbial community structure in suspension was quite different from each others depending on feed substrates, while the community structure in the biofilm was relatively similar regardless of the substrates. This result suggests that the feed substrates would affect the microbial community of suspended growth bacteria than attached growth bacteria resulting in difference of electricity generation in MFCs.

• KSBB Journal
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• 제22권6호
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• pp.438-442
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• 2007

본 연구는 3-전극계와 전기화학적 활성미생물 (EAB)을 이용한 BOD 측정용 바이오센서의 개발에 대한 것이다. 바이오센서의 측정능력 조사를 위하여, 인공폐수 및 실제폐수가 사용되었다. 폐수 시료의 유입조건은 유입속도 2 mL/min, 유입시간 10분, 유입간격은 50분으로 설정하였고, EAB의 전자수용체로 정전압이 적용된 작업전극을 사용하였으며 이때, 정전압기 (potentiostat)를 이용하여 +0.7 V를 인가하여 주었다. 인공폐수와 실제폐수를 이용한 BOD 측정의 정확성 분석결과, BOD 변화에 대해 발생전류 역시 비례적으로 변화하는 것을 확인하였으며 각각 0.99 및 0.98의 높은 상관계수 (BOD vs. Coulombic yield, $BOD_5$ vs. Coulombic yield)를 가지는 것을 확인하였다. BOD (혹은 $BOD_5$) 변화에 대한 반응시간은 30분 이내로 확인되어 실시간 측정에 적합함을 확인할 수 있었다. 이러한 결과들을 토대로 EAB 및 3-전극계를 이용한 폐수의 BOD 측정용 센서의 구성이 가능함을 확인하였다.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2001년도 Proceedings of 2001 KSAM Annual Meeting
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• pp.25-27
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• 2001

• Journal of Microbiology and Biotechnology
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• 제16권2호
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• pp.163-177
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• 2006

• Environmental Engineering Research
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• 제13권2호
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• pp.51-65
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• 2008

The increasing demand for energy in the near future has created strong motivation for environmentally clean alternative energy resources. Microbial fuel cells (MFCs) have opened up new ways of utilizing renewable energy sources. MFCs are devices that convert the chemical energy in the organic compounds to electrical energy through microbial catalysis at the anode under anaerobic conditions, and the reduction of a terminal electron acceptor, most preferentially oxygen, at the cathode. Due to the rapid advances in MFC-based technology over the last decade, the currently achievable MFC power production has increased by several orders of magnitude, and niche applications have been extended into a variety of areas. Newly emerging concepts with alternative materials for electrodes and catalysts as well as innovative designs have made MFCs promising technologies. Aerobic bacteria can also be used as cathode catalysts. This is an encouraging finding because not only biofouling on the cathode is unavoidable in the prolonged-run MFCs but also noble catalysts can be substituted with aerobic bacteria. This article discusses some of the recent advances in MFCs with an emphasis on the performance, materials, microbial community structures and applications beyond electricity generation.