• Bulletin of the Korean Chemical Society
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• v.33 no.8
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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.

• KSBB Journal
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• v.22 no.6
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• pp.438-442
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• 2007

A biosensor using electrochemically-active bacteria (EAB) enriched in three-electrode electrochemical cell, was developed for the determination of biochemical oxygen demand (BOD) in wastewater. In the electrochemical cell, the positively poised working electrode with applying a potential of 0.7 V was used as an electron acceptor for the EAB. The experimental results using artificial and raw wastewater showed that the current pattern generated by the biosensor and its Coulombic yield were proportional to the concentration of organic matter in wastewater. The correlation coefficients of BOD vs Coulombic yield and $BOD_5$ vs Coulombic yield were 0.99 and 0.98, respectively. These results indicate that the biosensor enriched with the EAB capable of transferring electrons directly toward the electrode can be utilized as a water-quality monitoring system due to a quick and accurate response.

• Journal of Microbiology and Biotechnology
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• v.16 no.9
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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.

• Journal of Microbiology and Biotechnology
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• v.16 no.2
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• pp.163-177
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• 2006

• Journal of Korean Society on Water Environment
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• v.26 no.4
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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.