The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Microbial activity in soils frozen to below-39 degrees C

Author

  • NS Panikov
  • PW Flanagan
  • WC Oechel
  • Mikhail Mastepanov
  • Torben Christensen

Summary, in English

Recent research on life in extreme environments has shown that some microorganisms metabolize at extremely low temperatures in Arctic and Antarctic ice and permafrost. Here, we present kinetic data on CO2 and (CO2)-C-14 release from intact and C-14-glucose amended tundra soils (Barrow, Alaska) incubated for up to a year at 0 to -39 degrees C. The rate of CO2 production declined exponentially with temperature but it remained positive and measurable, e.g. 2-7 ng CO2-C cm(-3) soil d(-1), at -39 degrees C. The variation of CO2 release rate (v) was adequately explained by the double exponential dependence on temperature (T) and unfrozen water content (W) (r(2)> 0.98): v=A exp(lambda T+kW) and where A, lambda and k are constants. The rate of (CO2)-C-14 release from added glucose declined more steeply with cooling as compared with the release of total CO2, indicating that (a) there could be some abiotic component in the measured flux of CO2 or (b) endogenous respiration is more cold-resistant than substrate-induced respiration. The respiration activity was completely eliminated by soil sterilization (1 h, 121 degrees C), stimulated by the addition of oxidizable substrate (glucose, yeast extract), and reduced by the addition of acetate, which inhibits microbial processes in acidic soils (pH 3-5). The tundra soil from Barrow displayed higher below-zero activity than boreal soils from West Siberia and Sweden. The permafrost soils (20-30 cm) were more active than the samples from seasonally frozen topsoil (0-10 cm, Barrow). Finding measurable respiration to -39 degrees C is significant for determining, understanding, and predicting current and future CO2 emission to the atmosphere and for understanding the low temperature limits of microbial activity on the Earth and on other planets. (c) 2005 Elsevier Ltd. All rights reserved.

Publishing year

2006

Language

English

Pages

785-794

Publication/Series

Soil Biology & Biochemistry

Volume

38

Issue

4

Document type

Journal article

Publisher

Elsevier

Topic

  • Physical Geography

Keywords

  • respiration
  • arctic soil respiration
  • kinetic analysis
  • psychrophiles
  • winter emission
  • CO2 entrapment
  • unfrozen water

Status

Published

ISBN/ISSN/Other

  • ISSN: 0038-0717