Microbial Ecology to Ocean Carbon Cycling: From Genomes to Numerical Models

The oceans contain large reservoirs of inorganic and organic carbon and play a critical role in both global carbon cycling and climate. Most of the biogeochemical transformations in the oceans are driven by marine microbes. Thus, molecular processes occurring at the scale of single cells govern global geochemical dynamics, posing a challenge of scales. Understanding the processes controlling ocean carbon cycling from the cellular to the global scale requires the integration of multiple disciplines including microbiology, ecology, biogeochemistry, and computational fields such as numerical models and bioinformatics. A shared language and foundational knowledge will facilitate these interactions. This review provides the state of knowledge on the role marine microbes play in large-scale ocean carbon cycling through the lens of observational oceanography and biogeochemical models. We conclude by outlining ways in which the field can bridge the gap between -omics datasets and ocean models to understand ocean carbon cycling across scales. ▪ -Omic approaches are providing increasingly quantitative insight into the biogeochemical functions of marine microbial ecosystems. ▪ Numerical models provide a tool for studying global carbon cycling by scaling from the microscale to the global scale. ▪ The integration of -omics and numerical modeling generates new understanding of how microbial metabolisms and community dynamics set nutrient fluxes in the ocean.