2026/03/09 by Emile Faure, Jolann Pommellec, Cyril Noël +18 · 1 voice
Environmental Science · Earth and Planetary Sciences · #Microbial Community Ecology and Physiology #Polar Research and Ecology #Marine and coastal ecosystems
paper · pdf · doi:10.1038/s41467-026-69584-w
openalex publication_date 2026/03/09 · openalex created_date 2026/03/10 · openalex updated_date 2026/07/29
The Southern Ocean (SO) plays a key role in regulating global biogeochemical cycles and climate, yet microbial genes sustaining its biological activity remain poorly characterized. We introduce a microbial genes collection from 218 metagenomes sampled during the Antarctic Circumnavigation Expedition, the majority of which are missing from functional databases. 38% even lack homologs in current reference marine gene catalogs, defining a singular genetic seascape. We show that SO gene assemblages exhibit a common polar signature with the Arctic Ocean while being structured by water masses at the SO-scale. We analyze genomic markers of diverse SO biomes, focusing on dimethylsulphoniopropionate (DMSP) cleavage by polar-adapted bacteria, organic matter consumption in the blooming Mertz polynya and adaptation to polar conditions in the ubiquitous bacteria Pelagibacter. Our work takes a step towards a comprehensive understanding of SO's plankton ecology and evolution, capturing the current state of the unique microbial diversity in this rapidly changing Ocean.