title: Acetogens and acetoclastic methanosarcinales govern methane formation in abandoned coal mines.
abstract: In abandoned coal mines, methanogenic archaea are responsible for the production of substantial amounts of methane. The present study aimed to directly unravel the active methanogens mediating methane release as well as active bacteria potentially involved in the trophic network. Therefore, the stable-isotope-labeled precursors of methane, [(13)C]acetate and H(2)-(13)CO(2), were fed to liquid cultures from hard coal and mine timber from a coal mine in Germany. Guided by methane production rates, samples for DNA stable-isotope probing (SIP) with subsequent quantitative PCR and denaturing gradient gel electrophoretic (DGGE) analyses were taken over 6 months. Surprisingly, the formation of [(13)C]methane was linked to acetoclastic methanogenesis in both the [(13)C]acetate- and the H(2)-(13)CO(2)-amended cultures of coal and timber. H(2)-(13)CO(2) was used mainly by acetogens related to Pelobacter acetylenicus and Clostridium species. Active methanogens, closely affiliated with Methanosarcina barkeri, utilized the readily available acetate rather than the thermodynamically more favorable hydrogen. Thus, the methanogenic microbial community appears to be highly adapted to the low-H(2) conditions found in coal mines.
authors: Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, Carl-von-Ossietzky Straße, 9-11, D-26129 Oldenburg, Germany. cypionka@icbm.de
authors: Sabrina
authors: S
authors: Beckmann
authors: Tillmann
authors: T
authors: Lueders
authors: Martin
authors: M
authors: Krüger
authors: Frederick
authors: F
authors: von Netzer
authors: Bert
authors: B
authors: Engelen
authors: Heribert
authors: H
authors: Cypionka
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D044822:Biodiversity; D002247:Carbon Isotopes / Q000378:metabolism; D002255:Carbonic Acid / Q000378:metabolism; D016000:Cluster Analysis; D003031:Coal; D019641:DNA, Archaeal / Q000737:chemistry / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D058645:Denaturing Gradient Gel Electrophoresis; D020459:Genes, rRNA; D005858:Germany; D007553:Isotope Labeling; D008697:Methane / Q000378:metabolism*; D019640:Methanosarcinales / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D019642:RNA, Archaeal / Q000235:genetics; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D012988:Soil Microbiology
chemical_list: D002247:Carbon Isotopes; D003031:Coal; D019641:DNA, Archaeal; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D019642:RNA, Archaeal; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D002255:Carbonic Acid; D008697:Methane