The Geochemistry, Ecology and Taxonomy of Antarctic Methanogenic Bacteria

• Other Authors: FRANZMANN, PETER (hasPrincipalInvestigator), FRANZMANN, PETER (processor), Australian Antarctic Data Centre (publisher)
• Format: Dataset
• Language: unknown
• Published: Australian Antarctic Data Centre
• Subjects: biota; BACTERIA/ARCHAEA; EARTH SCIENCE; BIOLOGICAL CLASSIFICATION; EARTH SCIENCE > BIOSPHERE > ECOSYSTEMS > FRESHWATER ECOSYSTEMS > LAKE/POND; 16S RRNA; ACE LAKE; ANTARCTIC PROKARYOTES; BACTERIA; BIODIVERSITY; METHANOGENIC; PHYLOGENY; PSYCHROTROPHS; CONTINENT > ANTARCTICA > Vestfold Hills; GEOGRAPHIC REGION > POLAR; Ace Lake; Antarctic; Four Lakes; Southern Ocean; The Antarctic; Vestfold; Antarc*; Antarctica
• Online Access: https://researchdata.ands.org.au/geochemistry-ecology-taxonomy-methanogenic-bacteria/699971; https://data.aad.gov.au/metadata/records/ASAC_264; http://nla.gov.au/nla.party-617536

The Antarctic methanogen Methanococcoides burtonii contained only diether phospholipids. These membrane components were analysed by gas chromatography and gas chromatography mass spectrometry. Of particular interest was the occurrence of unsaturated diether lipids in M. burtonii; unsaturated ether lipids accounted for 57% of the diether phospholipids. To our knowledge, unsaturated ether lipids have not been previously reported in a methanogen. The presence of the unsaturated ether lipids in M. burtonii is probably the result of temperature adaptation by the bacterium. it may be possible to use these components as a chemical signature for methanogens in Antarctic and Southern Ocean environments. From the abstract of one of the papers: The 16S rRNAs of nine new species of prokaryotes, that had been isolated from four lakes of the Vestfold Hills, have been sequenced. These sequences were compared with those of their closest taxonomic relatives available from publicly available databases. The Antarctic species were of wide diversity with representatives from the domains Archaea and Bacteria (sensu Woese). Generally, they were most closely related to organisms from marine environments. The sequence dissimilarity between the rRNA sequences of the Antarctic strains and their nearest known relatives suggest they diverged from each other much earlier than the establishment of their modern Antarctic habitat. The conserved nature of the 16S rRNA molecule suggests it may not be as useful for detecting evolutionary change in Antarctic prokaryotes as distinct from non-Antarctic prokaryotes. Although the optimal temperature for growth of each species is well above the temperature of its environment, each has a reduced optimal temperature for growth when compared with its taxonomic counterpart from non-Antarctic environments. The vast majority of Antarctic prokaryotes remains to be described.