Impact of in situ solar irradiation on snow bacterial communities and functional potential

• Published in: FEMS Microbiology Ecology
• Main Authors: Sanchez-Cid, Concepcion, Keuschnig, Christoph, Vogel, Timothy, Larose, Catherine
• Other Authors: Ampère, Département Bioingénierie (BioIng), Ampère (AMPERE), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-École Centrale de Lyon (ECL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), This work was funded by the IPEV Microlife project
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: metagenomics; polar microbiology; solar irradiation; ultraviolet light; [SDE]Environmental Sciences; Ny-Ålesund; Svalbard; Ny Ålesund
• Online Access: https://hal.science/hal-04316133; https://doi.org/10.1093/femsec/fiad042

International audience Polar regions are increasingly exposed to ultraviolet light due to ozone depletion. Snowpacks contain photochemically active particles that, when irradiated, can lead to the production and accumulation of reactive species that can induce oxidative stress on snow microorganisms. This could generate a selective pressure on snowpack bacteria. In this study, snow microcosms were buried in a snowpack at Ny-Ålesund (Svalbard), either exposed to solar irradiation or incubated in the dark for 10 days, and the bacterial response to solar irradiation was evaluated in situ using a metagenomics approach. Solar irradiation induced a significant decrease in bacterial abundance and richness. Genes involved in glutathione synthesis, sulphur metabolism, and multidrug efflux were significantly enriched in the light, whereas genes related to cell wall assembly and nutrient uptake were more abundant in the dark. This is the first study demonstrating the response of snow bacterial communities to solar irradiation in situ and providing insights into the mechanisms involved. Our research shows that polar sun irradiation is sufficiently intense to impose a selective pressure on snow bacteria and supports the concern that increased ultraviolet exposure due to anthropogenic activities and climatic change could drive critical changes in the structure and functioning of snow bacterial communities.