High pCO2-induced exopolysaccharide-rich ballasted aggregates of planktonic cyanobacteria could explain Paleoproterozoic carbon burial

Abstract

A Paleoproterozoic carbon isotope anomaly is likely linked to burial of oceanic cyanobacteria, but it is not clear how burial occurred. Here, the authors find that, under Paleoproterozoic pCO2 conditions, planktonic cyanobacteria increase exopolysaccharide production and mineralization, leading to aggregation and faster sinking.