Possible influence of hydrogen concentration on microbial methane stable hydrogen isotopic composition

Technical Report · Fri Jan 01 04:00:00 EST 1993

OSTI ID:6144971

Burke, R A

Factors affecting the stable hydrogen isotopic composition (delta D) of important sources of microbial methane to the atmosphere include oxidation, methanogenic precursor (e.g., acetate vs. CO2/H2), and the delta D of the environmental water. Variations in hydrogen gas concentrations or rates of interspecies hydrogen transfer resulting from variations in organic matter degradation rates may also affect delta D-CH4. Methane produced via CO2 reduction by laboratory cultures was more D-depleted than methane produced in shallow marine sediments from CO2/H2. The dissolved hydrogen gas concentration in that laboratory culture was about 1mM; whereas, hydrogen concentrations in methane-zone sediments typically range between 10 and 100 nM. The relatively greater hydrogen isotope fractionation in the culture appears to result from the incorporation into methane of protons that are produced intracellularly from the hydrogenase-catalyzed oxidation of hydrogen gas.

• Research Organization: Environmental Protection Agency, Athens, GA (United States). Environmental Research Lab.
• OSTI ID: 6144971
• Report Number(s): PB-93-205128/XAB; EPA--600/J-93/229
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540120* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
550200 -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
AIR POLLUTION
ALKANES
ATMOSPHERIC CHEMISTRY
BACTERIA
BIOCHEMISTRY
BIODEGRADATION
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISTRY
DECOMPOSITION
HYDROCARBONS
HYDROGEN ISOTOPES
ISOTOPE RATIO
ISOTOPES
MATTER
METHANE
METHANOGENIC BACTERIA
MICROORGANISMS
ORGANIC COMPOUNDS
ORGANIC MATTER
OXIDATION
OXIDES
OXYGEN COMPOUNDS
POLLUTION