The puy de Dôme station, a sampling site for clouds

The puy de Dôme station is labelled as a GAW (Global Atmosphere Watch) station. Cloud water is collected at the top of this mountain with cloud droplet samplers and analyzed for its microbial and chemical content ( The laboratory has now a unique microbial bank of about 1000 isolates from clouds.


  • L. DEGUILLAUME, T. CHARBOUILLOT, M. JOLY, M. VAÏTILINGOM, M. PARAZOLS, A. MARINONI, P. AMATO, A.-M. DELORT, V. VINATIER, A. FLOSSMANN, N. CHAUMERLIAC, J.-M. PICHON, S. HOUDIER, P. LAJ, K. SELLEGRI, A. COLOMB, M. BRIGANTE, G. MAILHOT. Classification of clouds sampled at the puy de Dôme (France) from 10-year monitoring : Mean features of their physico-chemical properties. Atmospheric Chemistry and Physics, 2014, 14, 1485-1506.
  • T. ŠANTL-TEMKIV, P. AMATO, U. GOSEWINKEL, R. THYRHAUG, A. CHARTON, B. CHICOT, K. FINSTER, G. BRATBAK, J. LÖNDAHL. A high-flow-rate impinger for the study of concentration, metabolic viability, and ice nucleation activity of airborne bacteria. Environmental Science and Technology, 2017, 51, 11224-11234.
  • A.T. LEBEDEV, O. V. POLYAKOVA, D. M. MAZUR, V. B. ARTAEV, I. CANET, A. LALLEMENT, M. VAITILINGOM, L. DEGUILLAUME, A.-M. DELORT. Detection of semi-volatile compounds in cloud waters by GCxGC-TOF-MS. Evidence of phenols and phthalates as priority pollutants. Environnmental Pollution, 2018, 241, 616-625.

Role of the micro-organisms living in clouds in atmospheric chemistry

Aim: to characterize microbial activity in clouds in order to evaluate its impact on the chemical reactivity of these environments and on biogeochemical cycles. The interactions between micro-organisms recovered from cloud water and some of the key chemical species involved in atmospheric chemistry: free radical (hydroxides OH●, superoxides O2●- and nitrates NO3●) and their precursors (H2O2, iron, organic complexes) as well as iron organic ligands from biological origin (siderophores…) are studied.


Cloud water microcosms incubated under controlled conditions in the laboratory
Production of pyoverdin, a fluorescent siderophore, by a bacteria isolated from cloud water collected at the puy de Dôme station


  • M. VAÏTILINGOM, L. DEGUILLAUME, V. VINATIER, M. SANCELME, P. AMATO, N. CHAUMERLIAC, A-M DELORT Potential impact of microbial activity on the oxidant capacity and organic carbon budget in clouds. Proceedings of the National Academy of Science USA, 2013, 110, 559-564.
  • V. VINATIER, N. WIRGOT, M. JOLY, M. SANCELME, M.ABRANTES, L. DEGUILLAUME, A.-M. DELORT. Siderophores in Cloud Waters and Potential Impact on Atmospheric Chemistry : Production by Microorganisms Isolated at the Puy de Dôme Station. Environmental Science and Technology, 2016, 50, 9315-9323.
  • N. WIRGOT, V. VINATIER, L. DEGUILLAUME, M. SANCELME, A.-M. DELORT H2O2 modulates the energetic metabolism of the cloud microbiome. Atmospheric Chemistry and Physics, 2017, 17, 14841-14851.

Atmospheric microphysics

The nucleation properties of micro-organisms isolated from clouds (ice-nucleation activity, bio-surfactant production) and their impact on the formation and behaviour of clouds (crystal formation, precipitation) are studied.

Droplet-freezing assays (20µL droplets on a cryobath) for investigating the capacity of some microbial strains to catalyze the nucleation of supercooled water into ice crystals.


  • M. JOLY, P. AMATO, L. DEGUILLAUME, M. MONIER, C. HOOSE, A.-M. DELORT Quantification of ice nuclei active at near 0°C temperatures in low-altitude clouds at the Puy de Dôme atmospheric station. Atmospheric Chemistry and Physics, 2014, 14, 8185-8195.
  • G. POUZET, E. PEGHAIRE, M. AGUÈS, J.-L. BARAY, F. CONEN, P. AMATO.Atmospheric processing and variability of biological ice nucleating particles in precipitation at Opme, France. Atmosphere, 2017, 8, 229.
  • P. RENARD, I. CANET, M. SANCELME, N. WIRGOT, L. DEGUILLAUME, A.-M. DELORT. Screening of cloud microorganisms isolated at the puy de Dôme (France) station for the production of biosurfactants. Atmospheric Chemistry and Physics, 2016, 16, 12347-12358 (highlight article).

Hanging drop method for measuring the surface tension of biosurfactants produced by microbial strains isolated from clouds

Survival mechanism of micro-organisms from clouds

In order to understand how some microorganisms survive in clouds, the group studies their response to factors encountered in these media (high rates of UV, low temperatures, repeated osmotic stress, freeze-thaw cycles, etc).

Schematic representation of the life cycle of microorganisms in the atmosphere. Microbes are emitted from surfaces (water, soil, vegetation), get airborne and transported upward by turbulent fluxes. They are subject to environmental conditions (indicated in red boxes) in the atmosphere that likely filter for the more resistant of them. In cloud droplets, viable microorganisms can participate to the degradation of organic compounds, and some species can nucleate freezing and, in theory, induce precipitations. They are finally wet deposited and in a position for colonizing new environments. (Scheme extracted from a publication signed by our group in Microbes Magazine in March 2012).


  • M. JOLY, P. AMATO, M. SANCELME, V. VINATIER, M. ABRANTES, L. DEGUILLAUME, A.-M. DELORT Survival of microbial isolates from clouds toward simulated atmospheric stress factors. Atmospheric Environment, 2015, 117, 92-98.
  • P. AMATO, M. JOLY, C. SCHAUPP, E. ATTARD, O. MOEHLER, C. E ; MORRIS, Y. BRUNET, A.-M. DELORT Survival and ice nucleation activity of bacteria as aerosol in a cloud simulation chamber. Atmospheric Chemistry and Physics, 2015, 15, 6455-6465.

Integrative biology of clouds: “meta-omics”

The idea is to look directly in situ in cloud waters the functional and structural biodiversity (metagenomics) of microorganisms and the expression of these functions (meta-transcriptomics). The impact of the cloud environment on microbial metabolome is studied by meta-metabolomics.


 P. AMATO, M. JOLY, L. BESAURY, A. OUDART, N. TAIB, A. MONÉ, L. DEGUILLAUME, A.-M. DELORT, D. DEBROAS. Active microorganisms thrive among extremely diverse communities in cloud water. PLoS ONE, 2017, August 8, 1-22.
  • C. JOUSSE, C. DALLE, I. CANET, M. LAGRÉE, M. TRAIKIA, B. LYAN, C. MENDES, M. SANCELME, P. AMATO, A.-M. DELORT. Metabolomic study of the response to cold shock in a strain of Pseudomonas syringae isolated from cloud water. Metabolomics, 2018, 14, 11.
  • A. LALLEMENT, L. BESAURY, E. TIXIER, M. SANCELME, P. AMATO, V. VINATIER, I. CANET, O.V. POLYAKOVA,V.B ARTAEV, L. DEGUILLAUME, G. MAILHOT, A.-M. DELORT. Potential for phenol biodegradation in cloud waters. Biogeoscience, 2018, 15, 5733-5744, doi:10.5194/bg-15-1-2018.

Intégration de l’activité microbienne dans les modèles de chimie et physique atmosphérique

Cette activité combine de manière très originale l’expertise expérimentale du groupe pour collecter des données microbiologiques et le développement de modèles de chimie et physique atmosphériques. Les données in situ (dans le nuage) concernant les processus microbiologiques ainsi que les activités glaçogènes de particules biologiques seront utilisées pour créer de nouveaux modules pour des modèles numériques à différentes échelles (nuage, meso-échelle, régionale). Ces outils permettront de simuler et prédire le rôle de l’activité microbienne dans la composition des nuages.


  • B. ERVENS, A. SOROOSHIAN, A. M. ALDHAIF, T. SHINGLER, E. CROSBIE, L. ZIEMBA, P. CAMPUZANO-JOST, J. L. JIMENEZ, A. WISTHALER Is there an aerosol signature of cloud processing ?, Atmos. Chem. Phys. Discuss. 2018,
  • B. ERVENS Modeling the Processing of Aerosol and Trace Gases in Clouds and Fogs. Chemical Reviews 2015, 115, 4157−4198.
  • B. ERVENS, B. J. TURPIN, R. J. WEBER Secondary organic aerosol formation in cloud droplets and aqueous particles (aqSOA) : a review of laboratory, field and model studies, Atmos. Chem. Phys, 2011, 11 11069-11102.