Microbiology of Methane Hydrates
he methane gas hydrates found in
sediments along continental mar-
gins and beneath permafrost are
a remarkable natural fuel resource. They
dwarf all other fossil fuels in terms of their
potential as an energy resource. These
hydrates, however, may also represent an
important environmental hazard: methane
release could contribute to global warming.
We need to understand the environmental
implications of methane hydrates and their
behavior and distribution in the subsurface
environment. The methane in hydrates is
largely a metabolic waste product, yet little
is understood about the microbial com-
The Energy of Innovation
munities in the sediments that produce the
Progress and the location of the hydrate biological information. Mod-
INL researchers are study- in the sediments. An INL elers need realistic methane
ing the basic microbial and team has collaborated in three production rates to estimate
chemical processes that form international coring efforts off the extent of the huge meth-
methane proximal to the the coast of Japan and on the ane hydrate resource in the
hydrates. Vertical sections of Mackenzie Delta in Canada’s earth.
the hydrate-rich sediments Northwest Territories.
Ongoing research activities
have been sampled, and the A principal objective is to include growing microbes
microbial communities have determine the in situ rates collected from the subsurface
been characterized to deter- of methane production. This in bioreactors to determine
mine the relationship between requires knowing the types methane production rates
the location of the microbes of microbes, their under simulated in situ condi-
activity, their tions. Using the bioreactors,
biomass, and we have estimated the pres-
their distribution sure and temperature limits of
in the sediments. the microbes. DNA signatures
Current models of the various methanogens
for methane pro- have been obtained from a
duction contain range of geographic locations
no meaningful and subsurface depths.
Continued next page
Scientists drill in the Arctic during winter, to
characterize a natural gas hydrate deposit (photo
above); a micrograph, magnified 60 times, of
sediment particles from a natural gas hydrate bearing
formation (photo at left).
Continued from previous page
For more information Selected publications/presentations
F. S. Colwell, “Constraints on the Distribution of Microorgan-
isms in Subsurface Environments,” Subsurface Microbiology
Technical Contact and Biogeochemistry, J. K. Fredrickson and M. Fletcher, eds.,
Mark Delwiche, M.S. Wiley-Liss, Inc., 2001.
Phone (208) 526-1870 F. S. Colwell, invited speaker, International Continental
Fax (208) 526-0828 Drilling Program, Mallik Gas Hydrate Research Well Work-
Mark.Delwiche@inl.gov shop, July 2001.
F. S. Colwell, invited speaker, 5th RIDGE Theoretical Institute
Management Contact on the Subsurface Biosphere at Mid-Ocean Ridges, (Big Sky,
Don Maiers Montana) July 2000.
Phone (208) 526-6991 F. S. Colwell, M. E. Delwiche, D. Blackwelder,
Fax (208) 526-0828 M. S. Wilson, R. M. Lehman, and T. Uchida, “Microbial
Donald.Maiers@inl.gov Communities from Core Intervals, JAPEX/JNOC/GSC Mallik
2L-38 Gas Hydrate Research Well, Mackenzie Delta, North-
www.inl.gov/biologicalsystems west Territories, Canada,” Geological Survey of Canada
Bulletin 544, S. R. Dallimore, T. Uchida, T. S. Collett, eds.,
1999, pp. 189–195.
F. S. Colwell, invited speaker, Annual Meeting of the Ameri-
can Society for Microbiology: Special Session on Microbial
A U.S. Department of Energy Ecology of the Deep Subsurface (Atlanta, Georgia) May 1999.