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Proc Natl Acad Sci USA. Potential impact of microbial activity on the oxidant capacity and organic carbon budget in clouds
[Source: Proceedings of the National Academy of the Sciences of the United States of America, full page: (LINK). Abstract, edited.]
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Potential impact of microbial activity on the oxidant capacity and organic carbon budget in clouds
Mickael Va?tilingom<SUP>a</SUP>,<SUP>b</SUP>,<SUP>c</SUP>,<SUP>d</SUP>, Laurent Deguillaume<SUP>c</SUP>,<SUP>d</SUP>, Virginie Vinatier<SUP>a</SUP>,<SUP>b</SUP>, Martine Sancelme<SUP>a</SUP>,<SUP>b</SUP>, Pierre Amato<SUP>a</SUP>,<SUP>b</SUP>, Nadine Chaumerliac<SUP>c</SUP>,<SUP>d</SUP>, and Anne-Marie Delort<SUP>a</SUP>,<SUP>b</SUP>,<SUP>1</SUP>
<SUP></SUP>
Author Affiliations: <SUP>a</SUP>Institut de Chimie de Clermont-Ferrand and <SUP>c</SUP>Observatoire de Physique du Globe de Clermont-Ferrand, Laboratoire de M?t?orologie Physique, Clermont Universit?, Universit? Blaise Pascal, BP 10448, F-63000 Clermont-Ferrand, France; <SUP>b</SUP>Centre National de la Recherche Scientifique, Unit? Mixte de Recherche 6296, Institut de Chimie de Clermont-Ferrand, BP 80026, F-63171 Aubi?re, France; and <SUP>d</SUP>Centre National de la Recherche Scientifique, Unit? Mixte de Recherche 6016, Laboratoire de M?t?orologie Physique/Observatoire de Physique du Globe de Clermont-Ferrand, BP 80026, F-63177 Aubi?re, France
Edited by V. Ramanathan, University of California at San Diego, La Jolla, CA, and approved November 19, 2012 (received for review April 6, 2012)
Abstract
Within cloud water, microorganisms are metabolically active and, thus, are expected to contribute to the atmospheric chemistry. This article investigates the interactions between microorganisms and the reactive oxygenated species that are present in cloud water because these chemical compounds drive the oxidant capacity of the cloud system. Real cloud water samples with contrasting features (marine, continental, and urban) were taken from the puy de D?me mountain (France). The samples exhibited a high microbial biodiversity and complex chemical composition. The media were incubated in the dark and subjected to UV radiation in specifically designed photo-bioreactors. The concentrations of H<SUB>2</SUB>O<SUB>2</SUB>, organic compounds, and the ATP/ADP ratio were monitored during the incubation period. The microorganisms remained metabolically active in the presence of <SUP>?</SUP>OH radicals that were photo-produced from H<SUB>2</SUB>O<SUB>2</SUB>. This oxidant and major carbon compounds (formaldehyde and carboxylic acids) were biodegraded by the endogenous microflora. This work suggests that microorganisms could play a double role in atmospheric chemistry; first, they could directly metabolize organic carbon species, and second, they could reduce the available source of radicals through their oxidative metabolism. Consequently, molecules such as H<SUB>2</SUB>O<SUB>2</SUB> would no longer be available for photochemical or other chemical reactions, which would decrease the cloud oxidant capacity.
biodegradation - cloud chemistry
Footnotes
<SUP>1</SUP>To whom correspondence should be addressed. E-mail: A-Marie.DELORT@univ-bpclermont.fr.
Author contributions: M.V., L.D., and A.-M.D. designed research; M.V. and L.D. performed research; M.V., V.V., and M.S. contributed new reagents/analytic tools; M.V. analyzed data; and M.V., L.D., V.V., P.A., N.C., and A.-M.D. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1205743110/-/DCSupplemental.
-Mickael Va?tilingom<SUP>a</SUP>,<SUP>b</SUP>,<SUP>c</SUP>,<SUP>d</SUP>, Laurent Deguillaume<SUP>c</SUP>,<SUP>d</SUP>, Virginie Vinatier<SUP>a</SUP>,<SUP>b</SUP>, Martine Sancelme<SUP>a</SUP>,<SUP>b</SUP>, Pierre Amato<SUP>a</SUP>,<SUP>b</SUP>, Nadine Chaumerliac<SUP>c</SUP>,<SUP>d</SUP>, and Anne-Marie Delort<SUP>a</SUP>,<SUP>b</SUP>,<SUP>1</SUP>
<SUP></SUP>
Author Affiliations: <SUP>a</SUP>Institut de Chimie de Clermont-Ferrand and <SUP>c</SUP>Observatoire de Physique du Globe de Clermont-Ferrand, Laboratoire de M?t?orologie Physique, Clermont Universit?, Universit? Blaise Pascal, BP 10448, F-63000 Clermont-Ferrand, France; <SUP>b</SUP>Centre National de la Recherche Scientifique, Unit? Mixte de Recherche 6296, Institut de Chimie de Clermont-Ferrand, BP 80026, F-63171 Aubi?re, France; and <SUP>d</SUP>Centre National de la Recherche Scientifique, Unit? Mixte de Recherche 6016, Laboratoire de M?t?orologie Physique/Observatoire de Physique du Globe de Clermont-Ferrand, BP 80026, F-63177 Aubi?re, France
Edited by V. Ramanathan, University of California at San Diego, La Jolla, CA, and approved November 19, 2012 (received for review April 6, 2012)
Abstract
Within cloud water, microorganisms are metabolically active and, thus, are expected to contribute to the atmospheric chemistry. This article investigates the interactions between microorganisms and the reactive oxygenated species that are present in cloud water because these chemical compounds drive the oxidant capacity of the cloud system. Real cloud water samples with contrasting features (marine, continental, and urban) were taken from the puy de D?me mountain (France). The samples exhibited a high microbial biodiversity and complex chemical composition. The media were incubated in the dark and subjected to UV radiation in specifically designed photo-bioreactors. The concentrations of H<SUB>2</SUB>O<SUB>2</SUB>, organic compounds, and the ATP/ADP ratio were monitored during the incubation period. The microorganisms remained metabolically active in the presence of <SUP>?</SUP>OH radicals that were photo-produced from H<SUB>2</SUB>O<SUB>2</SUB>. This oxidant and major carbon compounds (formaldehyde and carboxylic acids) were biodegraded by the endogenous microflora. This work suggests that microorganisms could play a double role in atmospheric chemistry; first, they could directly metabolize organic carbon species, and second, they could reduce the available source of radicals through their oxidative metabolism. Consequently, molecules such as H<SUB>2</SUB>O<SUB>2</SUB> would no longer be available for photochemical or other chemical reactions, which would decrease the cloud oxidant capacity.
biodegradation - cloud chemistry
Footnotes
<SUP>1</SUP>To whom correspondence should be addressed. E-mail: A-Marie.DELORT@univ-bpclermont.fr.
Author contributions: M.V., L.D., and A.-M.D. designed research; M.V. and L.D. performed research; M.V., V.V., and M.S. contributed new reagents/analytic tools; M.V. analyzed data; and M.V., L.D., V.V., P.A., N.C., and A.-M.D. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1205743110/-/DCSupplemental.
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