Methanogens on Clay and Basalt: Implications on Life o

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Methanogens on Clay and Basalt Implications on
Life on Mars
Edgar Siyakurima1,Travis Altheide2, and Timothy
A. Kral2 1 Wiley College, Marshall, TX, 2
Department of Biological Sciences, University of
Arkansas, Fayetteville, AR.
Background and Introduction Methane findings of
10 parts in a billion of Mars atmosphere
intrigued scientists over the several
possibilities of the sources. Of major interest
are methanogens, methane producing anaerobic
archaea, common on Earth in areas of
low electron acceptors (oxygen, nitrates,
sulfates) like the abysses of wetlands, swamps,
muddy-lakes, desert soils and the guts of animals
including humans where they aid cellulose
digestion and often cause intestinal gas. As such
research has been aimed at finding out whether
methanogens can survive on Mars by observing
their metabolism in different soil types similar
to those onthat planet.
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Research Synopsis Methanogens grow fastest and
best in different environments, but they all use
carbon dioxide and hydrogen gas as carbon and
energy sources respectively. From the various
kinds, we are working with three of them,
namely i) M.barkeri (optimum temperature-37oC)
ii)M. formicicum (same as M. barkeri) iii)M.
wolfeii (optimum temperature- 54-56oC) The
objective of our research is to expand on
previous researchers efforts to other
near-Martian substrates especially clay and
basalt. For comparison and control purposes we
included mars soil simulant and glass beads in
the laboratory experiment. Procedure -grow new
cultures of each of the three types of
methanogens in ideal laboratory media from old
cultures of each. -wash-off media and then
transfer to the clay, basalt, mars soil simulant
and glass beads. -observe gas chromatography for
methane every 3 days until readings are stable
then transfer to fresh substrates.
fig. 3
fig. 1
Observations Conclusions -As evidenced by the
graphs (fig.1,2 and 3) so far most of the
cultures seem to be showing some activity.
-notably the usually slowest M. barkeri is giving
the best results in clay so far while M. wolfeii
is doing the same in basalt. -it is too early to
conclude anything yet to whether or not they
survive in clay and basalt because they might be
still using reserves to sustain themselves or
some media that was not washed-off. Substantial
and critical data will only be available after
cultures in glass beads (the control) are not
indicating any methane presence. We have already
made the first transfer only for those tubes
exhibiting an increasing methane production
trend.
fig. 2
References Kral, Tim A, Bekkum, Curtis R.,
Mckay,Christopher P.,2004, Growth of Methanogens
on Mars soil simulant, Origins of Life and
Evolution of the Biosphere 34, 615-626. Oliver,
Heaven A., 2003. A comparison of methanogenic
growth on various soil substrates. Masters
Thesis.