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. 1970 Jan;19(1):32–38. doi: 10.1128/am.19.1.32-38.1970

Measurement of 14CO2 Assimilation in Soils: an Experiment for the Biological Exploration of Mars

Jerry S Hubbard 1, George L Hobby 1, Norman H Horowitz 1, Paul J Geiger 1,1, Frank A Morelli 1
PMCID: PMC376604  PMID: 16349879

Abstract

A method is described for the measurement of 14CO2 assimilation by microorganisms in soils. A determination involves exposing soil to 14CO2, pyrolyzing the exposed soil, trapping the organic pyrolysis products on a column of firebrick coated with CuO, combusting the trapped organics by heating, and measuring the radioactivity in the CO2 produced in the combustion. The detection of significant levels of 14C in the trapped organic fraction appears to be an unambiguous indication of biological activity. The 14CO2 which is adsorbed or exchanged into soils by nonbiological processes does not interfere. The method easily detects the 14CO2 fixed by 102 to 103 algae after light exposure for 3 to 24 hr. Assimilation of 14C is also demonstrable in dark-exposed soils containing 105 to 106 heterotrophic bacteria. Possible applications of the method in the biological exploration of Mars are discussed.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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