AUTHOR=Gründger Friederike , Jiménez Núria , Thielemann Thomas , Straaten Nontje , Lüders Tillmann , Richnow Hans-Hermann , Krüger Martin 

TITLE=Microbial methane formation in deep aquifers of a coal-bearing sedimentary basin, Germany

JOURNAL=Frontiers in Microbiology

VOLUME=Volume 6 - 2015

YEAR=2015

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2015.00200

DOI=10.3389/fmicb.2015.00200

ISSN=1664-302X

ABSTRACT=<p>Coal-bearing sediments are major reservoirs of organic matter potentially available for methanogenic subsurface microbial communities. In this study the specific microbial community inside lignite-bearing sedimentary basin in Germany and its contribution to methanogenic hydrocarbon degradation processes was investigated. The stable isotope signature of methane measured in groundwater and coal-rich sediment samples indicated methanogenic activity. Analysis of 16S rRNA gene sequences showed the presence of methanogenic <italic>Archaea</italic>, predominantly belonging to the orders <italic>Methanosarcinales</italic> and <italic>Methanomicrobiales</italic>, capable of acetoclastic or hydrogenotrophic methanogenesis. Furthermore, we identified fermenting, sulfate-, nitrate-, and metal-reducing, or acetogenic <italic>Bacteria</italic> clustering within the phyla <italic>Proteobacteria</italic>, complemented by members of the classes <italic>Actinobacteria</italic>, and <italic>Clostridia</italic>. The indigenous microbial communities found in the groundwater as well as in the coal-rich sediments are able to degrade coal-derived organic components and to produce methane as the final product. Lignite-bearing sediments may be an important nutrient and energy source influencing larger compartments via groundwater transport.</p>