Epiphytic Bacteria Are Essential for the Production and Transformation of Algae-Derived Carboxyl-Rich Alicyclic Molecule (CRAM)-like DOM

Dissolved organic matter (DOM) serves as a major carbon and nutrient pool in oceans, and recalcitrant DOM are the primary sources for carbon sequestration in depths. Here, we demonstrate the critical roles of algae-associated microorganisms (mainly heterotrophic bacteria) in the transformation of recalcitrant dissolved organic matter through laboratory cultures of a model diatom, Skeletonema dohrnii .