Analysis of the microbial community of the biocathode of a hydrogen-producing microbial electrolysis cell

Croese, Elsemiek; Pereira, Maria Alcina; Euverink, Gert-Jan W.; Stams, Alfons J. M.; Geelhoed, Jeanine S.

doi:10.1007/S00253-011-3583-X

Title

Analysis of the microbial community of the biocathode of a hydrogen-producing microbial electrolysis cell

Author

Croese, Elsemiek

Pereira, Maria Alcina

Euverink, Gert-Jan W.

Stams, Alfons J. M.

Geelhoed, Jeanine S.

Abstract

The microbial electrolysis cell (MEC) is a promising system for hydrogen production. Still, expensive catalysts such as platinum are needed for efficient hydrogen evolution at the cathode. Recently, the possibility to use a biocathode as an alternative for platinum was shown. The microorganisms involved in hydrogen evolution in such systems are not yet identified. We analyzed the microbial community of a mixed culture biocathode that was enriched in an MEC bioanode. This biocathode produced 1.1 A m(-2) and 0.63 m(3) H(2) m(-3) cathode liquid volume per day. The bacterial population consisted of 46% Proteobacteria, 25% Firmicutes, 17% Bacteroidetes, and 12% related to other phyla. The dominant ribotype belonged to the species Desulfovibrio vulgaris. The second major ribotype cluster constituted a novel taxonomic group at the genus level, clustering within uncultured Firmicutes. The third cluster belonged to uncultured Bacteroidetes and grouped in a taxonomic group from which only clones were described before; most of these clones originated from soil samples. The identified novel taxonomic groups developed under environmentally unusual conditions, and this may point to properties that have not been considered before. A pure culture of Desulfovibrio strain G11 inoculated in a cathode of an MEC led to a current development from 0.17 to 0.76 A m(-2) in 9 days, and hydrogen gas formation was observed. On the basis of the known characteristics of Desulfovibrio spp., including its ability to produce hydrogen, we propose a mechanism for hydrogen evolution through Desulfovibrio spp. in a biocathode system.

Language

English

Source (journal)

Applied microbiology and biotechnology. - Berlin, 1984, currens

Publication

Berlin : 2011

ISSN

0175-7598 [print]

1432-0614 [online]

DOI

10.1007/S00253-011-3583-X

Volume/pages