The utilization of bioelectrochemical systems for methane production has attracted increasing attention, but producing methane in these systems requires additional voltage to overcome large cathode overpotentials. To eliminate the need for electrical grid energy, we constructed a microbial reverse-electrodialysis methanogenesis cell (MRMC) by placing a reverse electrodialysis (RED) stack betwee...

Microbial solar cells (MSCs) are microbial fuel cells (MFCs) that generate their own oxidant and/or fuel through photosynthetic reactions. Here, we present electrochemical analyses and biofilm 16S rRNA gene profiling of biocathodes of sediment/seawater-based MSCs inoculated from the biocathode of a previously described sediment/seawater-based MSC. Electrochemical analyses indicate that for thes...

Biocathode microbial communities are proposed to catalyse a range of useful reactions. Unlike bioanodes, model biocathode organisms have not yet been successfully cultivated in isolation highlighting the need for culture-independent approaches to characterization. Biocathode MCL (Marinobacter, Chromatiaceae, Labrenzia) is a microbial community proposed to couple CO2 fixation to extracellular el...

A draft genome of Methanothermobacter sp. strain EMTCatA1 was reconstructed from a metagenome of a thermophilic electromethanogenic biocathode. This genome will provide information about methanogens catalyzing methanogenesis at the biocathodes.

A methane-producing biocathode that converts CO(2) into methane was studied electrochemically and microbiologically. The biocathode produced methane at a maximum rate of 5.1 L CH(4)/m(2) projected cathode per day (1.6 A/m(2)) at -0.7 V versus NHE cathode potential and 3.0 L CH(4)/m(2) projected cathode per day (0.9 A/m(2)) at -0.6 V versus NHE cathode potential. The microbial community at the b...

Microorganisms that respire electrodes may be exploited for biotechnology applications if key pathways for extracellular electron transfer can be identified and manipulated through bioengineering. To determine whether expression of proposed Biocathode-MCL extracellular electron transfer proteins are changed by modulating electrode potential without disrupting the relative distribution of microb...

Biofilms are the core component of bioelectrochemical systems (BESs). To understand the polarization effects on biocathode performance of BES, dissolved oxygen concentrations, pHs and oxidation-reduction potentials of biofilm microenvironments were determined in situ. The results showed that lower polarization potentials resulted in the generation of larger currents and higher pH values, as wel...

Setting a biocathode potential at -300 mV improved the subsequent performance of an MFC for Cr(VI) reduction compared to a control (no set potential). With this set potential, the startup time was reduced to 19 days, the reduction of Cr(VI) was improved to 19.7 mg/L d, and the maximum power density was increased to 6.4 W/m(3) compared to the control (26 days, 14.0 mg/L d and 4.1 W/m(3)). Set po...

Current microbial desalination cell (MDC) performances are evaluated with chemical catalysts such as ferricyanide, platinum catalyzed air-cathodes or aerated cathodes. All of these methods improve power generation potential in MDCs, however, they are not preferable for large scale applications due to cost, energy and environmental toxicity issues. In this study, performance of microbial desalin...

Reversible bioelectrodes were designed by alternating acetate and oxygen supply. It was demonstrated that the protons produced and accumulated inside the biofilm during the anodic phase greatly favored the oxygen reduction reaction when the electrode was switched to become the biocathode. Protons accumulation, which hindered the bioanode operation, thus became an advantage for the biocathode. T...