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DOI

  • Helen J Jones
    School of Health and Life Sciences , Teesside University , Middlesbrough , UKThe University of Warwick
  • Eileen Kröber
    Microbial Biogeochemistry
  • Jason Stephenson
    The University of Warwick
  • Michaela A Mausz
    The University of Warwick
  • Eleanor Jameson
    School of Health and Life Sciences , Teesside University , Middlesbrough , UKThe University of Warwick
  • Andrew Millard
    Leicester University
  • Kevin J Purdy
    The University of Warwick
  • Yin Chen
    The University of Warwick

BACKGROUND: Coastal environments are dynamic and rapidly changing. Living organisms in coastal environments are known to synthesise large quantities of organic osmolytes, which they use to cope with osmotic stresses. The organic osmolyte glycine betaine (GBT) is ubiquitously found in marine biota from prokaryotic Bacteria and Archaea to coastal plants, marine protozoa, and mammals. In intertidal coastal sediment, GBT represents an important precursor of natural methane emissions and as much as 90% of total methane production in these ecosystems can be originated from methanogenesis from GBT and its intermediate trimethylamine through microbial metabolism.

RESULTS: We set out to uncover the microorganisms responsible for methanogenesis from GBT using stable isotope labelling and metagenomics. This led to the recovery of a near-complete genome (2.3 Mbp) of a novel clostridial bacterium involved in anaerobic GBT degradation. Phylogenetic analyses of 16S rRNA gene, functional marker genes, and comparative genomics analyses all support the establishment of a novel family Candidatus 'Betainaceae' fam. nov. in Clostridiales and its role in GBT metabolism.

CONCLUSIONS: Our comparative genomes and metagenomics analyses suggest that this bacterium is widely distributed in coastal salt marshes, marine sediments, and deep subsurface sediments, suggesting a key role of anaerobic GBT metabolism by this clostridial bacterium in these ecosystems.

Keywords

  • Bacteria/classification, Betaine/metabolism, Geologic Sediments/microbiology, Metagenomics, Methane/metabolism, Osmosis, Phylogeny, RNA, Ribosomal, 16S/genetics, Seawater/microbiology, United Kingdom, Wetlands
Original languageEnglish
Article number120
JournalMicrobiome
Volume7
Issue number1
DOIs
Publication statusPublished - 27 Aug 2019
Externally publishedYes
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