Deep-sea trenches, such as Mariana, Atacama or Kermadec trenches are among the most extreme habitats on earth with hydrostatic pressure exceeding 1000x the one from ocean surface. Yet, these habitats are colonized by abundant and diverse microbial communities remarkably adapted to these environments. Recently, we have collected sediment cores from Atacama and Kermadec trenches along a bathyal gradient ranging from abyssal plains at (-3000m) to deepest points of two trenches (-9000m) and have sequenced 215 metagenomes from varying water and sediment depth.
Lab. Microbiologie des Environnments Extremes, LM2E - UMR6197
Comparatively little is known on the ecology and biodiversity of microorganisms living in the Southern Ocean and their genomic and metabolic adaptations to this unique environment. Marine microorganisms are central in the carbon cycling, though the combined process of photosynthesis (CO2 fixation), microbial loop (carbon recycling) and pump (carbon export). The comprehension of marine microorganism diversity, activity and biogeography is thus of paramount importance to better understand and predict the fate of marine and atmospheric carbon globally.