Articles | Volume 22, issue 1
https://doi.org/10.5194/bg-22-243-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-22-243-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Ideas and perspectives
| 
13 Jan 2025
Ideas and perspectives |
| 13 Jan 2025
| 13 Jan 2025
Ideas and perspectives: Microorganisms in the air through the lenses of atmospheric chemistry and microphysics
Institute of Chemistry Clermont-Ferrand, Université Clermont Auvergne, CNRS, 63000 Clermont-Ferrand, France
Pierre Amato
Institute of Chemistry Clermont-Ferrand, Université Clermont Auvergne, CNRS, 63000 Clermont-Ferrand, France
Laboratoire Microorganismes: Génome et Environnement (LMGE), Université Clermont Auvergne, CNRS, 63000 Clermont-Ferrand, France
Kifle Aregahegn
Institute of Chemistry Clermont-Ferrand, Université Clermont Auvergne, CNRS, 63000 Clermont-Ferrand, France
now at: Department of Chemistry, York University, Toronto, ON, Canada
Muriel Joly
Institute of Chemistry Clermont-Ferrand, Université Clermont Auvergne, CNRS, 63000 Clermont-Ferrand, France
Amina Khaled
Institute of Chemistry Clermont-Ferrand, Université Clermont Auvergne, CNRS, 63000 Clermont-Ferrand, France
Tiphaine Labed-Veydert
Institute of Chemistry Clermont-Ferrand, Université Clermont Auvergne, CNRS, 63000 Clermont-Ferrand, France
Frédéric Mathonat
Institute of Chemistry Clermont-Ferrand, Université Clermont Auvergne, CNRS, 63000 Clermont-Ferrand, France
Leslie Nuñez López
Institute of Chemistry Clermont-Ferrand, Université Clermont Auvergne, CNRS, 63000 Clermont-Ferrand, France
Raphaëlle Péguilhan
Institute of Chemistry Clermont-Ferrand, Université Clermont Auvergne, CNRS, 63000 Clermont-Ferrand, France
now at: Department of Chemical and Biochemical Engineering, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
Minghui Zhang
Institute of Chemistry Clermont-Ferrand, Université Clermont Auvergne, CNRS, 63000 Clermont-Ferrand, France
now at: Minerva Research Group, Max Planck Institute for Chemistry, 55128 Mainz, Germany
Related authors
Ulrike Proske, John Hillier, Stefan Gaillard, Theresa Blume, Eduardo Queiroz Alves, Susanne Buiter, Ken S. Carslaw, Kirsten von Elverfeldt, Tim H. M. van Emmerik, Barbara Ervens, Rolf Hut, Sam Illingworth, Daniel Klotz, and Jonas Pyschik
EGUsphere, https://doi.org/10.5194/egusphere-2026-987, https://doi.org/10.5194/egusphere-2026-987, 2026
This preprint is open for discussion and under review for Geoscience Communication (GC).
Short summary
Short summary
We explain a new article type that is being introduced in participating EGU publications. "LESSONS" articles describe the Limitations, Errors, Surprises, Shortcomings and Opportunities for New Science emerging from the scientific process. The publication of non-positive results and associated learnings aims to complete an unbiased record of the research effort, contributes to open and transparent science, allows the authors and others to learn, and may open opportunities for new science.
Barbara Ervens, Ken S. Carslaw, Thomas Koop, and Ulrich Pöschl
Atmos. Chem. Phys., 25, 13903–13952, https://doi.org/10.5194/acp-25-13903-2025, https://doi.org/10.5194/acp-25-13903-2025, 2025
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Over 25 years, the European Geosciences Union (EGU) has demonstrated the success, viability and benefits of interactive open-access (OA) publishing with public peer review in its journals, its publishing platform EGUsphere and virtual compilations. The article summarizes the evolution of the EGU/Copernicus publications and of OA publishing with interactive public peer review at large by placing the EGU/Copernicus publications in the context of current and future global open science.
Frédéric Mathonat, François Enault, Raphaëlle Péguilhan, Muriel Joly, Mariline Théveniot, Jean-Luc Baray, Barbara Ervens, and Pierre Amato
EGUsphere, https://doi.org/10.5194/egusphere-2025-3534, https://doi.org/10.5194/egusphere-2025-3534, 2025
Short summary
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The atmosphere plays key roles in Earth’s biogeochemical cycles. Airborne microbes were demonstrated previously to participate in the processing of organic carbon in clouds. Using a combinaison of complementary methods, we examined here, for the first time, their potential contribution to the pool of nitrogen compounds. Airborne microorganisms interact with abundant forms of nitrogen in the air and cloud and we provide global estimates.
Raphaëlle Péguilhan, Florent Rossi, Muriel Joly, Engy Nasr, Bérénice Batut, François Enault, Barbara Ervens, and Pierre Amato
Biogeosciences, 22, 1257–1275, https://doi.org/10.5194/bg-22-1257-2025, https://doi.org/10.5194/bg-22-1257-2025, 2025
Short summary
Short summary
Using comparative metagenomics and metatranscriptomics, we examined the functioning of airborne microorganisms in clouds and a clear atmosphere. Clouds are atmospheric masses where multiple microbial processes are promoted compared with a clear atmosphere. Overrepresented microbial functions of interest include the processing of chemical compounds, biomass production, and regulation of oxidants. This has implications for biogeochemical cycles and microbial ecology.
Barbara Ervens, Andrew Rickard, Bernard Aumont, William P. L. Carter, Max McGillen, Abdelwahid Mellouki, John Orlando, Bénédicte Picquet-Varrault, Paul Seakins, William R. Stockwell, Luc Vereecken, and Timothy J. Wallington
Atmos. Chem. Phys., 24, 13317–13339, https://doi.org/10.5194/acp-24-13317-2024, https://doi.org/10.5194/acp-24-13317-2024, 2024
Short summary
Short summary
Chemical mechanisms describe the chemical processes in atmospheric models that are used to describe the changes in the atmospheric composition. Therefore, accurate chemical mechanisms are necessary to predict the evolution of air pollution and climate change. The article describes all steps that are needed to build chemical mechanisms and discusses the advances and needs of experimental and theoretical research activities needed to build reliable chemical mechanisms.
Leslie Nuñez López, Pierre Amato, and Barbara Ervens
Atmos. Chem. Phys., 24, 5181–5198, https://doi.org/10.5194/acp-24-5181-2024, https://doi.org/10.5194/acp-24-5181-2024, 2024
Short summary
Short summary
Living bacteria comprise a small particle fraction in the atmosphere. Our model study shows that atmospheric bacteria in clouds may efficiently biodegrade formic and acetic acids that affect the acidity of rain. We conclude that current atmospheric models underestimate losses of these acids as they only consider chemical processes. We suggest that biodegradation can affect atmospheric concentration not only of formic and acetic acids but also of other volatile, moderately soluble organics.
Amina Khaled, Minghui Zhang, and Barbara Ervens
Atmos. Chem. Phys., 22, 1989–2009, https://doi.org/10.5194/acp-22-1989-2022, https://doi.org/10.5194/acp-22-1989-2022, 2022
Short summary
Short summary
Chemical reactions with iron in clouds and aerosol form and cycle reactive oxygen species (ROS). Previous model studies assumed that all cloud droplets (particles) contain iron, while single-particle analyses showed otherwise. By means of a model, we explore the bias in predicted ROS budgets by distributing a given iron mass to either all or only a few droplets (particles). Implications for oxidation potential, radical loss and iron oxidation state are discussed.
Ramon Campos Braga, Barbara Ervens, Daniel Rosenfeld, Meinrat O. Andreae, Jan-David Förster, Daniel Fütterer, Lianet Hernández Pardo, Bruna A. Holanda, Tina Jurkat-Witschas, Ovid O. Krüger, Oliver Lauer, Luiz A. T. Machado, Christopher Pöhlker, Daniel Sauer, Christiane Voigt, Adrian Walser, Manfred Wendisch, Ulrich Pöschl, and Mira L. Pöhlker
Atmos. Chem. Phys., 21, 17513–17528, https://doi.org/10.5194/acp-21-17513-2021, https://doi.org/10.5194/acp-21-17513-2021, 2021
Short summary
Short summary
Interactions of aerosol particles with clouds represent a large uncertainty in estimates of climate change. Properties of aerosol particles control their ability to act as cloud condensation nuclei. Using aerosol measurements in the Amazon, we performed model studies to compare predicted and measured cloud droplet number concentrations at cloud bases. Our results confirm previous estimates of particle hygroscopicity in this region.
Ramon Campos Braga, Daniel Rosenfeld, Ovid O. Krüger, Barbara Ervens, Bruna A. Holanda, Manfred Wendisch, Trismono Krisna, Ulrich Pöschl, Meinrat O. Andreae, Christiane Voigt, and Mira L. Pöhlker
Atmos. Chem. Phys., 21, 14079–14088, https://doi.org/10.5194/acp-21-14079-2021, https://doi.org/10.5194/acp-21-14079-2021, 2021
Short summary
Short summary
Quantifying the precipitation within clouds is crucial for our understanding of the Earth's hydrological cycle. Using in situ measurements of cloud and rain properties over the Amazon Basin and Atlantic Ocean, we show here a linear relationship between the effective radius (re) and precipitation water content near the tops of convective clouds for different pollution states and temperature levels. Our results emphasize the role of re to determine both initiation and amount of precipitation.
Mira L. Pöhlker, Minghui Zhang, Ramon Campos Braga, Ovid O. Krüger, Ulrich Pöschl, and Barbara Ervens
Atmos. Chem. Phys., 21, 11723–11740, https://doi.org/10.5194/acp-21-11723-2021, https://doi.org/10.5194/acp-21-11723-2021, 2021
Short summary
Short summary
Clouds cool our atmosphere. The role of small aerosol particles in affecting them represents one of the largest uncertainties in current estimates of climate change. Traditionally it is assumed that cloud droplets only form particles of diameters ~ 100 nm (
accumulation mode). Previous studies suggest that this can also occur in smaller particles (
Aitken mode). Our study provides a general framework to estimate under which aerosol and cloud conditions Aitken mode particles affect clouds.
Ulrike Proske, John Hillier, Stefan Gaillard, Theresa Blume, Eduardo Queiroz Alves, Susanne Buiter, Ken S. Carslaw, Kirsten von Elverfeldt, Tim H. M. van Emmerik, Barbara Ervens, Rolf Hut, Sam Illingworth, Daniel Klotz, and Jonas Pyschik
EGUsphere, https://doi.org/10.5194/egusphere-2026-987, https://doi.org/10.5194/egusphere-2026-987, 2026
This preprint is open for discussion and under review for Geoscience Communication (GC).
Short summary
Short summary
We explain a new article type that is being introduced in participating EGU publications. "LESSONS" articles describe the Limitations, Errors, Surprises, Shortcomings and Opportunities for New Science emerging from the scientific process. The publication of non-positive results and associated learnings aims to complete an unbiased record of the research effort, contributes to open and transparent science, allows the authors and others to learn, and may open opportunities for new science.
Pauline Nibert, Yi Wu, Muriel Joly, Pierre Amato, Paolo Cristofanelli, Francescopiero Calzolari, Jean-Luc Piro, Davide Putero, Simonetta Montaguti, Laura Renzi, Franziska Vogel, Marco Rapuano, Marcello Brigante, Christophe Verhaege, Jean-Luc Baray, Laurent Deguillaume, Angela Marinoni, Marco Zanatta, and Angelica Bianco
EGUsphere, https://doi.org/10.5194/egusphere-2025-5976, https://doi.org/10.5194/egusphere-2025-5976, 2026
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This study provides the first chemical and microbiological characterization of cloud samples collected at Monte Cimone (ACTRIS, ICOS, GAW - CMN) in the Mediterranean basin. The chemical characterization is deeply discussed in relationship with back-trajectories and cloud processing. Air mass history do not fully explain the variability observed in the chemical composition. This highlights the complexity of emission sources, multiphasique exchanges, and transformations in clouds.
Barbara Ervens, Ken S. Carslaw, Thomas Koop, and Ulrich Pöschl
Atmos. Chem. Phys., 25, 13903–13952, https://doi.org/10.5194/acp-25-13903-2025, https://doi.org/10.5194/acp-25-13903-2025, 2025
Short summary
Short summary
Over 25 years, the European Geosciences Union (EGU) has demonstrated the success, viability and benefits of interactive open-access (OA) publishing with public peer review in its journals, its publishing platform EGUsphere and virtual compilations. The article summarizes the evolution of the EGU/Copernicus publications and of OA publishing with interactive public peer review at large by placing the EGU/Copernicus publications in the context of current and future global open science.
Frédéric Mathonat, François Enault, Raphaëlle Péguilhan, Muriel Joly, Mariline Théveniot, Jean-Luc Baray, Barbara Ervens, and Pierre Amato
EGUsphere, https://doi.org/10.5194/egusphere-2025-3534, https://doi.org/10.5194/egusphere-2025-3534, 2025
Short summary
Short summary
The atmosphere plays key roles in Earth’s biogeochemical cycles. Airborne microbes were demonstrated previously to participate in the processing of organic carbon in clouds. Using a combinaison of complementary methods, we examined here, for the first time, their potential contribution to the pool of nitrogen compounds. Airborne microorganisms interact with abundant forms of nitrogen in the air and cloud and we provide global estimates.
Elsa Abs, Christoph Keuschnig, Pierre Amato, Chris Bowler, Eric Capo, Alexander Chase, Luciana Chavez Rodriguez, Abraham Dabengwa, Thomas Dussarrat, Thomas Guzman, Linnea Honeker, Jenni Hultman, Kirsten Küsel, Zhen Li, Anna Mankowski, William Riley, Scott Saleska, and Lisa Wingate
EGUsphere, https://doi.org/10.5194/egusphere-2025-1716, https://doi.org/10.5194/egusphere-2025-1716, 2025
Short summary
Short summary
Meta-omics technologies offer new tools to understand how microbial and plant functional diversity shape biogeochemical cycles across ecosystems. This perspective explores how integrating omics data with ecological and modeling approaches can improve our understanding of greenhouse gas fluxes and nutrient dynamics, from soils to clouds, and from the past to the future. We highlight challenges and opportunities for scaling omics insights from local processes to Earth system models.
Raphaëlle Péguilhan, Florent Rossi, Muriel Joly, Engy Nasr, Bérénice Batut, François Enault, Barbara Ervens, and Pierre Amato
Biogeosciences, 22, 1257–1275, https://doi.org/10.5194/bg-22-1257-2025, https://doi.org/10.5194/bg-22-1257-2025, 2025
Short summary
Short summary
Using comparative metagenomics and metatranscriptomics, we examined the functioning of airborne microorganisms in clouds and a clear atmosphere. Clouds are atmospheric masses where multiple microbial processes are promoted compared with a clear atmosphere. Overrepresented microbial functions of interest include the processing of chemical compounds, biomass production, and regulation of oxidants. This has implications for biogeochemical cycles and microbial ecology.
Barbara Ervens, Andrew Rickard, Bernard Aumont, William P. L. Carter, Max McGillen, Abdelwahid Mellouki, John Orlando, Bénédicte Picquet-Varrault, Paul Seakins, William R. Stockwell, Luc Vereecken, and Timothy J. Wallington
Atmos. Chem. Phys., 24, 13317–13339, https://doi.org/10.5194/acp-24-13317-2024, https://doi.org/10.5194/acp-24-13317-2024, 2024
Short summary
Short summary
Chemical mechanisms describe the chemical processes in atmospheric models that are used to describe the changes in the atmospheric composition. Therefore, accurate chemical mechanisms are necessary to predict the evolution of air pollution and climate change. The article describes all steps that are needed to build chemical mechanisms and discusses the advances and needs of experimental and theoretical research activities needed to build reliable chemical mechanisms.
Leslie Nuñez López, Pierre Amato, and Barbara Ervens
Atmos. Chem. Phys., 24, 5181–5198, https://doi.org/10.5194/acp-24-5181-2024, https://doi.org/10.5194/acp-24-5181-2024, 2024
Short summary
Short summary
Living bacteria comprise a small particle fraction in the atmosphere. Our model study shows that atmospheric bacteria in clouds may efficiently biodegrade formic and acetic acids that affect the acidity of rain. We conclude that current atmospheric models underestimate losses of these acids as they only consider chemical processes. We suggest that biodegradation can affect atmospheric concentration not only of formic and acetic acids but also of other volatile, moderately soluble organics.
Maud Leriche, Pierre Tulet, Laurent Deguillaume, Frédéric Burnet, Aurélie Colomb, Agnès Borbon, Corinne Jambert, Valentin Duflot, Stéphan Houdier, Jean-Luc Jaffrezo, Mickaël Vaïtilingom, Pamela Dominutti, Manon Rocco, Camille Mouchel-Vallon, Samira El Gdachi, Maxence Brissy, Maroua Fathalli, Nicolas Maury, Bert Verreyken, Crist Amelynck, Niels Schoon, Valérie Gros, Jean-Marc Pichon, Mickael Ribeiro, Eric Pique, Emmanuel Leclerc, Thierry Bourrianne, Axel Roy, Eric Moulin, Joël Barrie, Jean-Marc Metzger, Guillaume Péris, Christian Guadagno, Chatrapatty Bhugwant, Jean-Mathieu Tibere, Arnaud Tournigand, Evelyn Freney, Karine Sellegri, Anne-Marie Delort, Pierre Amato, Muriel Joly, Jean-Luc Baray, Pascal Renard, Angelica Bianco, Anne Réchou, and Guillaume Payen
Atmos. Chem. Phys., 24, 4129–4155, https://doi.org/10.5194/acp-24-4129-2024, https://doi.org/10.5194/acp-24-4129-2024, 2024
Short summary
Short summary
Aerosol particles in the atmosphere play a key role in climate change and air pollution. A large number of aerosol particles are formed from the oxidation of volatile organic compounds (VOCs and secondary organic aerosols – SOA). An important field campaign was organized on Réunion in March–April 2019 to understand the formation of SOA in a tropical atmosphere mostly influenced by VOCs emitted by forest and in the presence of clouds. This work synthesizes the results of this campaign.
Amina Khaled, Minghui Zhang, and Barbara Ervens
Atmos. Chem. Phys., 22, 1989–2009, https://doi.org/10.5194/acp-22-1989-2022, https://doi.org/10.5194/acp-22-1989-2022, 2022
Short summary
Short summary
Chemical reactions with iron in clouds and aerosol form and cycle reactive oxygen species (ROS). Previous model studies assumed that all cloud droplets (particles) contain iron, while single-particle analyses showed otherwise. By means of a model, we explore the bias in predicted ROS budgets by distributing a given iron mass to either all or only a few droplets (particles). Implications for oxidation potential, radical loss and iron oxidation state are discussed.
Pamela A. Dominutti, Pascal Renard, Mickaël Vaïtilingom, Angelica Bianco, Jean-Luc Baray, Agnès Borbon, Thierry Bourianne, Frédéric Burnet, Aurélie Colomb, Anne-Marie Delort, Valentin Duflot, Stephan Houdier, Jean-Luc Jaffrezo, Muriel Joly, Martin Leremboure, Jean-Marc Metzger, Jean-Marc Pichon, Mickaël Ribeiro, Manon Rocco, Pierre Tulet, Anthony Vella, Maud Leriche, and Laurent Deguillaume
Atmos. Chem. Phys., 22, 505–533, https://doi.org/10.5194/acp-22-505-2022, https://doi.org/10.5194/acp-22-505-2022, 2022
Short summary
Short summary
We present here the results obtained during an intensive field campaign conducted in March to April 2019 in Reunion. Our study integrates a comprehensive chemical and microphysical characterization of cloud water. Our investigations reveal that air mass history and cloud microphysical properties do not fully explain the variability observed in their chemical composition. This highlights the complexity of emission sources, multiphasic exchanges, and transformations in clouds.
Ramon Campos Braga, Barbara Ervens, Daniel Rosenfeld, Meinrat O. Andreae, Jan-David Förster, Daniel Fütterer, Lianet Hernández Pardo, Bruna A. Holanda, Tina Jurkat-Witschas, Ovid O. Krüger, Oliver Lauer, Luiz A. T. Machado, Christopher Pöhlker, Daniel Sauer, Christiane Voigt, Adrian Walser, Manfred Wendisch, Ulrich Pöschl, and Mira L. Pöhlker
Atmos. Chem. Phys., 21, 17513–17528, https://doi.org/10.5194/acp-21-17513-2021, https://doi.org/10.5194/acp-21-17513-2021, 2021
Short summary
Short summary
Interactions of aerosol particles with clouds represent a large uncertainty in estimates of climate change. Properties of aerosol particles control their ability to act as cloud condensation nuclei. Using aerosol measurements in the Amazon, we performed model studies to compare predicted and measured cloud droplet number concentrations at cloud bases. Our results confirm previous estimates of particle hygroscopicity in this region.
Soleil E. Worthy, Anand Kumar, Yu Xi, Jingwei Yun, Jessie Chen, Cuishan Xu, Victoria E. Irish, Pierre Amato, and Allan K. Bertram
Atmos. Chem. Phys., 21, 14631–14648, https://doi.org/10.5194/acp-21-14631-2021, https://doi.org/10.5194/acp-21-14631-2021, 2021
Short summary
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We studied the effect of (NH4)2SO4 on the immersion freezing of non-mineral dust ice-nucleating substances (INSs) and mineral dusts. (NH4)2SO4 had no effect on the median freezing temperature of 9 of the 10 tested non-mineral dust INSs, slightly decreased that of the other, and increased that of all the mineral dusts. The difference in the response of mineral dust and non-mineral dust INSs to (NH4)2SO4 suggests that they nucleate ice and/or interact with (NH4)2SO4 via different mechanisms.
Ramon Campos Braga, Daniel Rosenfeld, Ovid O. Krüger, Barbara Ervens, Bruna A. Holanda, Manfred Wendisch, Trismono Krisna, Ulrich Pöschl, Meinrat O. Andreae, Christiane Voigt, and Mira L. Pöhlker
Atmos. Chem. Phys., 21, 14079–14088, https://doi.org/10.5194/acp-21-14079-2021, https://doi.org/10.5194/acp-21-14079-2021, 2021
Short summary
Short summary
Quantifying the precipitation within clouds is crucial for our understanding of the Earth's hydrological cycle. Using in situ measurements of cloud and rain properties over the Amazon Basin and Atlantic Ocean, we show here a linear relationship between the effective radius (re) and precipitation water content near the tops of convective clouds for different pollution states and temperature levels. Our results emphasize the role of re to determine both initiation and amount of precipitation.
Mira L. Pöhlker, Minghui Zhang, Ramon Campos Braga, Ovid O. Krüger, Ulrich Pöschl, and Barbara Ervens
Atmos. Chem. Phys., 21, 11723–11740, https://doi.org/10.5194/acp-21-11723-2021, https://doi.org/10.5194/acp-21-11723-2021, 2021
Short summary
Short summary
Clouds cool our atmosphere. The role of small aerosol particles in affecting them represents one of the largest uncertainties in current estimates of climate change. Traditionally it is assumed that cloud droplets only form particles of diameters ~ 100 nm (
accumulation mode). Previous studies suggest that this can also occur in smaller particles (
Aitken mode). Our study provides a general framework to estimate under which aerosol and cloud conditions Aitken mode particles affect clouds.
Cited articles
Amato, P., Joly, M., Besaury, L., Oudart, A., Taib, N., Moné, A. I., Deguillaume, L., Delort, A., and Debroas, D.: Active microorganisms thrive among extremely diverse communities in cloud water, PLOS One, 12, e0182869, https://doi.org/10.1371/journal.pone.0182869, 2017. a, b
Arakaki, T., Anastasio, C., Kuroki, Y., Nakajima, H., Okada, K., Kotani, Y., Handa, D., Azechi, S., Kimura, T., Tsuhako, A., and Miyagi, Y.: A general scavenging rate constant for reaction of hydroxyl radical with organic carbon in atmospheric waters, Environ. Sci. Technol., 47, 8196–8203, https://doi.org/10.1021/es401927b, 2013. a
Archer, S. D. J., Lee, K. C., Caruso, T., Maki, T., Lee, C. K., Cary, S. C., Cowan, D. A., Maestre, F. T., and Pointing, S. B.: Airborne microbial transport limitation to isolated Antarctic soil habitats, Nat. Microbiol., 4, 925–932, https://doi.org/10.1038/s41564-019-0370-4, 2019. a
Arellanes, C., Paulson, S. E., Fine, P. M., and Sioutas, C.: Exceeding of Henry's Law by Hydrogen Peroxide Associated with Urban Aerosols, Environ. Sci. Technol., 40, 4859–4866, https://doi.org/10.1021/es0513786, 2006. a
Bar-On, Y. M., Phillips, R., and Milo, R.: The biomass distribution on Earth, P. Natl. Acad. Sci. USA, 115, 6506–6511, https://doi.org/10.1073/pnas.1711842115, 2018. a
Boetius, A., Anesio, A. M., Deming, J. W., Mikucki, J. A., and Rapp, J. Z.: Microbial ecology of the cryosphere: sea ice and glacial habitats, Nat. Rev. Microbiol., 13, 677–690, https://doi.org/10.1038/nrmicro3522, 2015. a
Bryan, N. C., Christner, B. C., Guzik, T. G., Granger, D. J., and Stewart, M. F.: Abundance and survival of microbial aerosols in the troposphere and stratosphere, ISME J., 13, 2789–2799, https://doi.org/10.1038/s41396-019-0474-0, 2019. a
Burrows, S. M., Butler, T., Jöckel, P., Tost, H., Kerkweg, A., Pöschl, U., and Lawrence, M. G.: Bacteria in the global atmosphere – Part 2: Modeling of emissions and transport between different ecosystems, Atmos. Chem. Phys., 9, 9281–9297, https://doi.org/10.5194/acp-9-9281-2009, 2009a. a, b, c
Burrows, S. M., Elbert, W., Lawrence, M. G., and Pöschl, U.: Bacteria in the global atmosphere – Part 1: Review and synthesis of literature data for different ecosystems, Atmos. Chem. Phys., 9, 9263–9280, https://doi.org/10.5194/acp-9-9263-2009, 2009b. a
Cabiscol, E., Tamarit, J., and Ros, J.: Oxidative stress in bacteria and protein damage by reactive oxygen species, International microbiology: the official journal of the Spanish Society for Microbiology, 3, 3–8, 2000. a
Cardinale, B. J., Duffy, J. E., Gonzalez, A., Hooper, D. U., Perrings, C., Venail, P., Narwani, A., Mace, G. M., Tilman, D., Wardle, D. A., Kinzig, A. P., Daily, G. C., Loreau, M., Grace, J. B., Larigauderie, A., Srivastava, D. S., and Naeem, S.: Biodiversity loss and its impact on humanity, Nature, 486, 59–67, https://doi.org/10.1038/nature11148, 2012. a
Catalán, N., Casas-Ruiz, J. P., von Schiller, D., Proia, L., Obrador, B., Zwirnmann, E., and Marcé, R.: Biodegradation kinetics of dissolved organic matter chromatographic fractions in an intermittent river, J. Geophys. Res.-Biogeo., 122, 131–144, https://doi.org/10.1002/2016JG003512, 2017. a
del Giorgio, P. A. and Cole, J. J.: Bacterial growth efficiency in natural aquatic systems, Annu. Rev. Ecol. Syst., 29, 503–541, https://doi.org/10.1146/annurev.ecolsys.29.1.503, 1998. a
Després, V. R., Huffman, J. A., Burrows, S. M., Hoose, C., Safatov, A. S., Buryak, G., Fröhlich-Nowoisky, J., Elbert, W., Andreae, M. O., Pöschl, U., and Jaenicke, R.: Primary biological aerosol particles in the atmosphere: a review, Tellus B, 64, 15598, https://doi.org/10.3402/tellusb.v64i0.15598, 2012. a
Eiler, A., Langenheder, S., Bertilsson, S., and Tranvik, L. J.: Heterotrophic Bacterial Growth Efficiency and Community Structure at Different Natural Organic Carbon Concentrations, Appl. Environ. Microb., 69, 3701–3709, https://doi.org/10.1128/AEM.69.7.3701-3709.2003, 2003. a
Ervens, B.: Modeling the Processing of Aerosol and Trace Gases in Clouds and Fogs, Chem. Rev., 115, 4157–4198, https://doi.org/10.1021/cr5005887, 2015. a
Ervens, B.: Average cloud droplet size and composition: Good assumptions for predicting oxidants in the atmospheric aqueous phase?, J. Phys. Chem. A, 126, 8295–8304, https://doi.org/10.1021/acs.jpca.2c05527, 2022. a
Ervens, B. and Amato, P.: The global impact of bacterial processes on carbon mass, Atmos. Chem. Phys., 20, 1777–1794, https://doi.org/10.5194/acp-20-1777-2020, 2020. a, b, c
Ervens, B., Sorooshian, A., Lim, Y. B., and Turpin, B. J.: Key parameters controlling OH-initiated formation of secondary organic aerosol in the aqueous phase (aqSOA), J. Geophys. Res.-Atmos., 119, 3997–4016, https://doi.org/10.1002/2013JD021021, 2014. a
Fankhauser, A. M., Antonio, D. D., Krell, A., Alston, S. J., Banta, S., and Mc Neill, V. F.: Constraining the Impact of Bacteria on the Aqueous Atmospheric Chemistry of Small Organic Compounds, ACS Earth Space Chem, 3, 1485–1491, https://doi.org/10.1021/acsearthspacechem.9b00054, 2019. a, b
Fernandez, M. O., Thomas, R. J., Garton, N. J., Hudson, A., Haddrell, A., and Reid, J. P.: Assessing the airborne survival of bacteria in populations of aerosol droplets with a novel technology, J. R. Soc. Interface, 16, 20180779, https://doi.org/10.1098/rsif.2018.0779, 2019. a
Gandolfi, I., Bertolini, V., Ambrosini, R., Bestetti, G., and Franzetti, A.: Unravelling the bacterial diversity in the atmosphere, Applied Microbiology and Biotechnology, 97, 4727–4736, https://doi.org/10.1007/s00253-013-4901-2, 2013. a
Gill, P. S., Graedel, T. E., and Weschler, C. J.: Organic films on atmospheric aerosol particles, fog droplets, cloud droplets, raindrops, and snowflakes, Rev. Geophys., 21, 903–920, https://doi.org/10.1029/RG021i004p00903, 1983. a, b
Guillemette, R., Harwell, M. C., and Brown, C. A.: Metabolically active bacteria detected with click chemistry in low organic matter rainwater, PLOS ONE, 18, e0285816, https://doi.org/10.1371/journal.pone.0285816, 2023. a
Gusareva, E. S., Acerbi, E., Lau, K. J. X., Luhung, I., Premkrishnan, B. N. V., Kolundžija, S., Purbojati, R. W., Wong, A., Houghton, J. N. I., Miller, D., Gaultier, N. E., Heinle, C. E., Clare, M. E., Vettath, V. K., Kee, C., Lim, S. B. Y., Chénard, C., Phung, W. J., Kushwaha, K. K., Nee, A. P., Putra, A., Panicker, D., Yanqing, K., Hwee, Y. Z., Lohar, S. R., Kuwata, M., Kim, H. L., Yang, L., Uchida, A., Drautz-Moses, D. I., Junqueira, A. C. M., and Schuster, S. C.: Microbial communities in the tropical air ecosystem follow a precise diel cycle, P. Natl. Acad. Sci. USA, 116, 201908493, https://doi.org/10.1073/pnas.1908493116, 2019. a
Haddrell, A. E. and Thomas, R. J.: Aerobiology: Experimental Considerations, Observations, and Future Tools, Appl. Environ. Microbiol., 83, e00809-17, https://doi.org/10.1128/AEM.00809-17, 2017. a
Herckes, P., Valsaraj, K. T., and Collett Jr., J. L.: A review of observations of organic matter in fogs and clouds: Origin, processing and fate, Atmos. Res., 132–133, 434–449, https://doi.org/10.1016/j.atmosres.2013.06.005, 2013. a, b
Innocente, E., Squizzato, S., Visin, F., Facca, C., Rampazzo, G., Bertolini, V., Gandolfi, I., Franzetti, A., Ambrosini, R., and Bestetti, G.: Influence of seasonality, air mass origin and particulate matter chemical composition on airborne bacterial community structure in the Po Valley, Italy, Sci. Total Environ., 593–594, 677–687, https://doi.org/10.1016/j.scitotenv.2017.03.199, 2017. a
Joly, M., Amato, P., Sancelme, M., Vinatier, V., Abrantes, M., Deguillaume, L., and Delort, A. M.: Survival of microbial isolates from clouds toward simulated atmospheric stress factors, Atmos. Environ., 117, 92–98, https://doi.org/10.1016/j.atmosenv.2015.07.009, 2015. a
Jones, S. E. and Lennon, J. T.: Dormancy contributes to the maintenance of microbial diversity, P. Natl. Acad. Sci. USA, 107, https://doi.org/10.1073/pnas.0912765107, 2010. a
Kaur, R. and Anastasio, C.: First Measurements of Organic Triplet Excited States in Atmospheric Waters, Environ. Sci. Technol., 52, 5218–5226, https://doi.org/10.1021/acs.est.7b06699, 2018. a
Khaled, A., Zhang, M., Amato, P., Delort, A.-M., and Ervens, B.: Biodegradation by bacteria in clouds: an underestimated sink for some organics in the atmospheric multiphase system, Atmos. Chem. Phys., 21, 3123–3141, https://doi.org/10.5194/acp-21-3123-2021, 2021. a
Khaled, A., Zhang, M., and Ervens, B.: The number fraction of iron-containing particles affects OH, HO2 and H2O2 budgets in the atmospheric aqueous phase, Atmos. Chem. Phys., 22, 1989–2009, https://doi.org/10.5194/acp-22-1989-2022, 2022. a
Kobayashi, H., Saito, H., and Kakegawa, T.: Bacterial strategies to inhabit acidic environments, J. Gen. Appl. Microbiol., 46, 235–243, https://doi.org/10.2323/jgam.46.235, 2000. a
Lebowitz, M. D. and O'rourke, M. K.: The significance of air pollution in aerobiology, Grana, 30, 31–43, https://doi.org/10.1080/00173139109427766, 1991. a
Leizeaga, A., Meisner, A., Rousk, J., and Bååth, E.: Repeated drying and rewetting cycles accelerate bacterial growth recovery after rewetting, Biol. Fert. Soils, 58, 365–374, https://doi.org/10.1007/s00374-022-01623-2, 2022. a
Lindow, S. E. and Brandl, M. T.: Microbiology of the phyllosphere, Appl. Environ. Microb., 69, 1875–1883, https://doi.org/10.1128/AEM.69.4.1875-1883.2003, 2003. a
Liu, J., Zhang, X., Parker, E. T., Veres, P. R., Roberts, J. M., de Gouw, J. A., Hayes, P. L., Jimenez, J. L., Murphy, J. G., Ellis, R. A., Huey, L. G., and Weber, R. J.: On the gas-particle partitioning of soluble organic aerosol in two urban atmospheres with contrasting emissions: 2. Gas and particle phase formic acid, J. Geophys. Res.-Atmos., 117, D00V21, https://doi.org/10.1029/2012jd017912, 2012. a
Liu, Y., Lee, P. K. H., and Nah, T.: Emerging investigator series: Aqueous photooxidation of live bacteria with hydroxyl radicals under clouds-like conditions: Insights into the production and transformation of biological and organic matter originating from bioaerosols, Environmental Science: Processes & Impacts, https://doi.org/10.1039/D3EM00090G, 2023. a, b
Lund, P. A., De Biase, D., Liran, O., Scheler, O., Mira, N. P., Cetecioglu, Z., Fernández, E. N., Bover-Cid, S., Hall, R., Sauer, M., and O'Byrne, C.: Understanding How Microorganisms Respond to Acid pH Is Central to Their Control and Successful Exploitation, Front. Microbiol., 11, 556140, https://doi.org/10.3389/fmicb.2020.556140, 2020. a
Ma, L., Worland, R., Tran, T., and Anastasio, C.: Evaluation of Probes to Measure Oxidizing Organic Triplet Excited States in Aerosol Liquid Water, Environ. Sci. Technol., 57, 6052–6062, https://doi.org/10.1021/acs.est.2c09672, 2023. a
Madronich, S., Björn, L. O., and McKenzie, R. L.: Solar UV radiation and microbial life in the atmosphere, Photoch. Photobio. Sci., 17, 1918–1931, https://doi.org/10.1039/C7PP00407A, 2018. a
Mopper, K. and Zhou, X.: Hydroxyl radical photoproduction in the sea and its potential impact on marine processes, Science, 250, 661–664, https://doi.org/10.1126/science.250.4981.661, 1990. a
Nielsen, L. S., Šantl-Temkiv, T., Palomeque Sánchez, M., Massling, A., Ward, J. C., Jensen, P. B., Boesen, T., Petters, M., Finster, K., Bilde, M., and Rosati, B.: Water Uptake of Airborne Cells of P. syringae Measured with a Hygroscopicity Tandem Differential Mobility Analyzer, Environ. Sci. Technol., 58, 19211–19221, https://doi.org/10.1021/acs.est.4c01817, 2024. a
Nuñez López, L., Amato, P., and Ervens, B.: Bacteria in clouds biodegrade atmospheric formic and acetic acids, Atmos. Chem. Phys., 24, 5181–5198, https://doi.org/10.5194/acp-24-5181-2024, 2024. a
Pailler, L., Wirgot, N., Joly, M., Renard, P., Mouchel-Vallon, C., Bianco, A., Leriche, M., Sancelme, M., Job, A., Patryl, L., Armand, P., Delort, A.-M., Chaumerliac, N., and Deguillaume, L.: Assessing the efficiency of water-soluble organic compound biodegradation in clouds under various environmental conditions, Environmental Science: Atmospheres, 3, 731–748, https://doi.org/10.1039/D2EA00153E, 2023. a
Pasteur, L.: Mémoire sur les corpuscles organisés qui existent dans l'atmosphère, examen de la doctrine des générations spontanées, Masson, 1861. a
Péguilhan, R., Rossi, F., Joly, M., Nasr, E., Batut, B., Enault, F., Ervens, B., and Amato, P.: Clouds, oases for airborne microbes – Differential metagenomics/metatranscriptomics analyses of cloudy and clear atmospheric situations, bioRxiv [preprint], 2023.12.14.571671, https://doi.org/10.1101/2023.12.14.571671, 2023. a
Péguilhan, R., Rossi, F., Joly, M., Nasr, E., Batut, B., Enault, F., Ervens, B., and Amato, P.: Clouds influence the functioning of airborne microorganisms, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2024-2338, 2024. a
Peterson, S. B., Bertolli, S. K., and Mougous, J. D.: The Central Role of Interbacterial Antagonism in Bacterial Life, Curr. Biol., 30, R1203–R1214, https://doi.org/10.1016/j.cub.2020.06.103, 2020. a
Poorter, H., Niinemets, Ü., Poorter, L., Wright, I. J., and Villar, R.: Causes and consequences of variation in leaf mass per area (LMA): a meta-analysis, New Phytol., 182, 565–588, https://doi.org/10.1111/j.1469-8137.2009.02830.x, 2009. a
Pöschl, U. and Shiraiwa, M.: Multiphase Chemistry at the Atmosphere–Biosphere Interface Influencing Climate and Public Health in the Anthropocene, Chem. Rev., 115, 4440–4475, https://doi.org/10.1021/cr500487s, 2015. a
Price, P. B. and Sowers, T.: Temperature dependence of metabolic rates for microbial growth, maintenance, and survival, P. Natl. Acad. Sci. USA, 101, 4631–4636, https://doi.org/10.1073/pnas.0400522101, 2004. a
Ratzke, C. and Gore, J.: Modifying and reacting to the environmental pH can drive bacterial interactions, PLOS Biol., 16, e2004248, https://doi.org/10.1371/journal.pbio.2004248, 2018. a
Robinson, J. M. and Breed, M. F.: The aerobiome–health axis: a paradigm shift in bioaerosol thinking, Trends Microbiol., 31, 661–664, https://doi.org/10.1016/j.tim.2023.04.007, 2023. a
Ross, B. N. and Whiteley, M.: Ignoring social distancing: advances in understanding multi-species bacterial interactions, Faculty Reviews, 9, 23, https://doi.org/10.12703/r/9-23, 2020. a
Russel, J., Røder, H. L., Madsen, J. S., Burmølle, M., and Sørensen, S. J.: Antagonism correlates with metabolic similarity in diverse bacteria, P. Natl. Acad. Sci. USA, 114, 10684–10688, https://doi.org/10.1073/pnas.1706016114, 2017. a
Ryu, Y.-H., Hodzic, A., Descombes, G., Hall, S., Minnis, P., Spangenberg, D., Ullmann, K., and Madronich, S.: Improved modeling of cloudy-sky actinic flux using satellite cloud retrievals, Geophys. Res. Lett., 44, 1592–1600, https://doi.org/10.1002/2016GL071892, 2017. a
Šantl-Temkiv, T., Amato, P., Casamayor, E. O., Lee, P. K. H., and Pointing, S. B.: Microbial ecology of the atmosphere, FEMS Microbiol. Rev., 46, fuac009, https://doi.org/10.1093/femsre/fuac009, 2022. a, b
Sattler, B., Puxbaum, H., and Psenner, R.: Bacterial growth in supercooled cloud droplets, Geophys. Res. Lett., 28, 239–242, https://doi.org/10.1029/2000GL011684, 2001. a, b
Scully, N. M., Cooper, W. J., and Tranvik, L. J.: Photochemical effects on microbial activity in natural waters: the interaction of reactive oxygen species and dissolved organic matter, FEMS Microbiol. Ecol., 46, 353–357, https://doi.org/10.1016/S0168-6496(03)00198-3, 2003. a
Seinfeld, J. H. and Pandis, S. N.: Atmospheric Chemistry and Physics – From air pollution to climate change, John Wiley & Sons, Inc., Hoboken, New Jersey, 2nd edn., ISBN 9780471720188, 2006. a
Smets, W., Moretti, S., Denys, S., and Lebeer, S.: Airborne bacteria in the atmosphere: Presence, purpose, and potential, Atmos. Environ., 139, 214–221, https://doi.org/10.1016/j.atmosenv.2016.05.038, 2016. a
Smith, D. J., Griffin, D. W., McPeters, R. D., Ward, P. D., and Schuerger, A. C.: Microbial survival in the stratosphere and implications for global dispersal, Aerobiologia, 27, 319–332, https://doi.org/10.1007/s10453-011-9203-5, 2011. a
Smith, D. J., Ravichandar, J. D., Jain, S., Griffin, D. W., Yu, H., Tan, Q., Thissen, J., Lusby, T., Nicoll, P., Shedler, S., Martinez, P., Osorio, A., Lechniak, J., Choi, S., Sabino, K., Iverson, K., Chan, L., Jaing, C., and McGrath, J.: Airborne Bacteria in Earth's Lower Stratosphere Resemble Taxa Detected in the Troposphere: Results From a New NASA Aircraft Bioaerosol Collector (ABC), Front. Microbiol., 9, 1752, https://doi.org/10.3389/fmicb.2018.01752, 2018. a
Stevenson, A., Burkhardt, J., Cockell, C. S., Cray, J. A., Dijksterhuis, J., Fox-Powell, M., Kee, T. P., Kminek, G., McGenity, T. J., Timmis, K. N., Timson, D. J., Voytek, M. A., Westall, F., Yakimov, M. M., and Hallsworth, J. E.: Multiplication of microbes below 0.690 water activity: implications for terrestrial and extraterrestrial life, Environ. Microbiol., 17, 257–277, https://doi.org/10.1111/1462-2920.12598, 2015. a
Stevenson, A., Hamill, P. G., O'Kane, C. J., Kminek, G., Rummel, J. D., Voytek, M. A., Dijksterhuis, J., and Hallsworth, J. E.: Aspergillus penicillioides differentiation and cell division at 0.585 water activity, Environ. Microbiol., 19, 687–697, https://doi.org/10.1111/1462-2920.13597, 2017. a
Tong, Y. and Lighthart, B.: Solar radiation has a lethal effect on natural populations of culturable outdoor atmospheric bacteria, Atmos. Environ., 31, 897–900, https://doi.org/10.1016/S1352-2310(96)00235-X, 1997. a
Vaïtilingom, M., Amato, P., Sancelme, M., Laj, P., Leriche, M., and Delort, A.-M.: Contribution of Microbial Activity to Carbon Chemistry in Clouds, Appl. Environ. Microb., 76, 23–29, https://doi.org/10.1128/AEM.01127-09, 2010. a, b, c
Vaïtilingom, M., Charbouillot, T., Deguillaume, L., Maisonobe, R., Parazols, M., Amato, P., Sancelme, M., and Delort, A.-M.: Atmospheric chemistry of carboxylic acids: microbial implication versus photochemistry, Atmos. Chem. Phys., 11, 8721–8733, https://doi.org/10.5194/acp-11-8721-2011, 2011. a, b
Vaïtilingom, M., Deguillaume, L., Vinatier, V., Samcelme, M., Amato, P., N, C., and A.-M, D.: Potential impact of microbial activity on the oxidant capacity and organic carbon budget in clouds, P. Natl. Acad. Sci. USA, 110, 559–564, https://doi.org/10.1073/pnas.1205743110, 2013. a, b
Wei, H., Vejerano, E. P., Leng, W., Huang, Q., Willner, M. R., Marr, L. C., and Vikesland, P. J.: Aerosol microdroplets exhibit a stable pH gradient, P. Natl. Acad. Sci. USA, 115, 7272–7277, https://doi.org/10.1073/pnas.1720488115, 2018. a
Whitman, W. B., Coleman, D. C., and Wiebe, W. J.: Prokaryotes: The unseen majority, P. Natl. Acad. Sci. USA, 95, 6578–6583, https://doi.org/10.1073/pnas.95.12.6578, 1998. a, b, c, d
Wirgot, N., Lagrée, M., Traïkia, M., Besaury, L., Amato, P., Canet, I., Sancelme, M., Jousse, C., Diémé, B., Lyan, B., and Delort, A.-M.: Metabolic modulations of Pseudomonas graminis in response to H2O2 in cloud water, Sci. Rep., 9, 12799, https://doi.org/10.1038/s41598-019-49319-2, 2019. a
Zhang, M., Khaled, A., Amato, P., Delort, A.-M., and Ervens, B.: Sensitivities to biological aerosol particle properties and ageing processes: potential implications for aerosol–cloud interactions and optical properties, Atmos. Chem. Phys., 21, 3699–3724, https://doi.org/10.5194/acp-21-3699-2021, 2021. a
Short summary
Atmospheric microorganisms are a small fraction of Earth's microbiome, with bacteria being a significant part. Aerosolized bacteria are airborne for a few days, encountering unique chemical and physical conditions affecting stress levels and survival. We explore chemical and microphysical conditions bacteria encounter, highlighting potential nutrient and oxidant limitations and diverse effects by pollutants, which may ultimately impact the microbiome's role in global ecosystems and biodiversity.
Atmospheric microorganisms are a small fraction of Earth's microbiome, with bacteria being a...
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