title: Biostimulation to identify microbial communities involved in methane generation in shallow, kerogen-rich shales.
abstract: OBJECTIVE
  The aim of the present study was to design and test a method allowing the detection and quantification of methanogenic consortia in organic-rich rocks to determine the potential of methane biotransformation.
  
  
  RESULTS
  Methanogen numbers in the rock are often below the detection levels of quantification methods. Biostimulation was tested as a means to specifically increase bacterial and archaeal numbers above the detection levels in microcosms. Biostimulation reveals the presence of active heterotrophic and syntrophic bacterial consortia, methane accumulation and methanogens in one of four rock samples. Syntrophs and heterotrophs were dominated by Firmicutes, whereas archaeal diversity was limited to methanogens. Methane-producing microcosms were characterized by a higher Firmicutes diversity.
  
  
  CONCLUSIONS
  Biostimulation is a reliable tool for detection of methanogenic consortia in organic-rich rocks. For routine and large scale experimentation, methane accumulation monitoring after biostimulation appears as the most time, work and cost efficient approach to detect the presence of active methanogenic consortia.
  
  
  CONCLUSIONS
  We report for the first time the presence of live methanogenic consortia in organic-rich shales and their ability to mineralize the rock into methane. This approach will be instrumental to quantify the potential of these rocks to produce methane as a novel energy source.
authors.affiliation: Ecole Normale Supérieure de Lyon, CNRS UMR 5276, Lyon, France.
authors.forename: M
authors.initials: M
authors.lastname: Meslé
authors.forename: C
authors.initials: C
authors.lastname: Périot
authors.forename: G
authors.initials: G
authors.lastname: Dromart
authors.forename: P
authors.initials: P
authors.lastname: Oger
mesh_terms: D001105:Archaea / Q000145:classification / Q000378:metabolism*; D001419:Bacteria / Q000145:classification / Q000378:metabolism*; D044822:Biodiversity; D001711:Biotransformation; D052836:Heterotrophic Processes; D008697:Methane / Q000378:metabolism*; D059013:Microbial Consortia; D010802:Phylogeny
chemical_list: D008697:Methane