Chemostat study reveals conserved carbon density in marine picocyanobacteria across nutrient conditions, improving global ocean biomass models.
Key Points
To determine how nitrogen limitation alters cellular carbon quota and cell volume in dominant picocyanobacteria, providing refined conversion factors for oceanic biomass.
Cultured Synechococcus and Prochlorococcus across varying levels of nitrogen limitation using controlled chemostat systems.
Compiled laboratory and literature data across diverse strains, light levels, and temperatures, integrating eukaryotic phytoplankton datasets across cell volumes from 10⁻¹ to 10⁷ μm³.
Synechococcus displayed continuous decreases in cell volume and carbon quota with worsening nitrogen limitation, whereas Prochlorococcus stabilized after an initial drop.
Both picocyanobacterial genera maintained an invariant organic carbon density of approximately 246 fg C μm⁻³ regardless of nutrient, light, or temperature variations.
Established a universal carbon-to-volume scaling model spanning eight orders of magnitude in cell volume (10⁻¹–10⁷ μm³).