Robert Karl Stonjek
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 Posted: Thu Jul 24, 2008 9:42 pm Post subject: Paper: Significant contribution of Archaea to extant biomass |
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Nature advance online publication 20 July 2008 | doi:10.1038/nature07174;
Received 12 March 2008; Accepted 17 June 2008; Published online 20 July 2008
Significant contribution of Archaea to extant biomass in marine subsurface
sediments
Julius S. Lipp 1, Yuki Morono 2, Fumio Inagaki 2 & Kai-Uwe Hinrichs 1
1) Organic Geochemistry Group, Department of Geosciences and MARUM Center
for Marine Environmental Sciences, University of Bremen, PO Box 330 440,
28334 Bremen, Germany
2) Geomicrobiology Group, Kochi Institute for Core Sample Research, Japan
Agency for Marine-Earth Science and Technology (JAMSTEC), Monobe B200,
Nankoku, Kochi 783-8502, Japan
Abstract:
Deep drilling into the marine sea floor has uncovered a vast sedimentary
ecosystem of microbial cells. Extrapolation of direct counts of stained
microbial cells to the total volume of habitable marine subsurface sediments
suggests that between 56 Pg (ref. 1) and 303 Pg (ref. 3) of cellular carbon
could be stored in this largely unexplored habitat. From recent studies
using various culture-independent techniques, no clear picture has yet
emerged as to whether Archaea or Bacteria are more abundant in this
extensive ecosystem. Here we show that in subsurface sediments buried deeper
than 1 m in a wide range of oceanographic settings at least 87% of intact
polar membrane lipids, biomarkers for the presence of live cells are
attributable to archaeal membranes, suggesting that Archaea constitute a
major fraction of the biomass. Results obtained from modified quantitative
polymerase chain reaction and slot-blot hybridization protocols support the
lipid-based evidence and indicate that these techniques have previously
underestimated archaeal biomass. The lipid concentrations are proportional
to those of total organic carbon. On the basis of this relationship, we
derived an independent estimate of amounts of cellular carbon in the global
marine subsurface biosphere. Our estimate of 90 Pg of cellular carbon is
consistent, within an order of magnitude, with previous estimates, and
underscores the importance of marine subsurface habitats for global biomass
budgets.
Source: Nature
http://www.nature.com/nature/journal/vaop/ncurrent/abs/nature07174.html
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Robert Karl Stonjek |
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