The Prochlorococcus carbon dioxide-concentrating mechanism: evidence of carboxysome-associated heterogeneity.

The ability of Prochlorococcus to numerically dominate open ocean regions and contribute significantly to global carbon cycles is dependent in large part on its effectiveness in transforming light energy into compounds used in cell growth, maintenance, and division. Integral to these processes is the carbon dioxide-concentrating mechanism (CCM), which enhances photosynthetic CO2 fixation. The CCM involves both active uptake systems that permit intracellular accumulation of inorganic carbon as the pool of bicarbonate and the system of HCO3 (-) conversion into CO2.