title: Enhancement of electricity production in a mediatorless air-cathode microbial fuel cell using Klebsiella sp. IR21.
abstract: A novel dissimilatory iron-reducing bacteria, Klebsiella sp. IR21, was isolated from the anode biofilm of an MFC reactor. Klebsiella sp. IR21 reduced 27.8 % of ferric iron to ferrous iron demonstrating that Klebsiella sp. IR21 has electron transfer ability. Additionally, Klebsiella sp. IR21 generated electricity forming a biofilm on the anode surface. When a pure culture of Klebsiella sp. IR21 was supplied into a single chamber, air-cathode MFC fed with a mixture of glucose and acetate (500 mg L(-1) COD), 40-60 mV of voltage (17-26 mA m(-2) of current density) was produced. Klebsiella sp. IR21 was also utilized as a biocatalyst to improve the electrical performance of a conventional MFC reactor. A single chamber, air-cathode MFC was fed with reject wastewater (10,000 mg L(-1) COD) from a H2 fermentation reactor. The average voltage, current density, and power density were 142.9 ± 25.74 mV, 60.5 ± 11.61 mA m(-2), and 8.9 ± 3.65 mW m(-2), respectively, in the MFC without inoculation of Klebsiella sp. IR21. However, these electrical performances of the MFC were significantly increased to 204.7 ± 40.24 mV, 87.5 ± 17.20 mA m(-2), and 18.6 ± 7.23 mW m(-2), respectively, with inoculation of Klebsiella sp. IR21. The results indicate that Klebsiella sp. IR21 can be utilized as a biocatalyst for enhancement of electrical performance in MFC systems.
authors.affiliation: Department of Environmental Science and Engineering, Ewha Womans University, 11-1 Daehyun-dong, Seodaemun-gu, Seoul, 120-750, Republic of Korea.
authors.forename: Yun-Yeong
authors.initials: YY
authors.lastname: Lee
authors.affiliation: Department of Environmental Science and Engineering, Ewha Womans University, 11-1 Daehyun-dong, Seodaemun-gu, Seoul, 120-750, Republic of Korea.
authors.forename: Tae Gwan
authors.initials: TG
authors.lastname: Kim
authors.affiliation: Department of Environmental Science and Engineering, Ewha Womans University, 11-1 Daehyun-dong, Seodaemun-gu, Seoul, 120-750, Republic of Korea. kscho@ewha.ac.kr.
authors.forename: Kyung-Suk
authors.initials: KS
authors.lastname: Cho
mesh_terms: D001674:Bioelectric Energy Sources; D004566:Electrodes; D005290:Ferric Compounds / Q000378:metabolism; D007709:Klebsiella / Q000378:metabolism*; D010084:Oxidation-Reduction
chemical_list: D005290:Ferric Compounds
keywords: Biocatalyst; Electricity; Iron-reducing bacteria; Klebsiella sp.; Microbial fuel cells