Methanogenesis
in acidic bog peat
Peats are wetland
ecosystems in which biomass production exceeds biodegradative activity,
are
often acidic, and emit approximately 3-7% of the global annual emission
of the
greenhouse gas methane (CH4).
Peats cover less than 3% of the earth’s terrestrial surface but
harbor
approximately 30% of the global reserves of soil carbon and soil
nitrogen, and
are often anoxic. In anoxic, pH neutral
environments with negligible concentrations of inorganic electron
acceptors
(e.g., sulfate or nitrate), methanogenesis is often the main terminal
microbiological process during the biodegradation of organic matter,
and
acetate is thought to be the main substrates for methanogenesis in such
habitats. However, the main precursor(s)
of methane in acidic peats is not well established
, and the methanogenic microbiota of such
environments have not been extensively
investigated. The main objectives
under study are to (i) determine the flow of carbon and reductant in a
regional
anoxic acidic bog peat and (ii) enumerate and characterize the
methanogenic
microbiota of this acidic peat with both cultivation and molecular
methods.