Microscopic organisms play a very important role in ocean carbon cycling, researchers have indicated.
When phytoplankton use carbon dioxide to make new cells, a substantial portion of that cellular material is released into the sea as a buffet of edible molecules collectively called "dissolved organic carbon."
The majority of these molecules are eventually eaten by microscopic marine bacteria, used for energy, and recycled back into carbon dioxide as the bacteria exhale. The amount of carbon that remains as cell material determines the role that ocean biology plays in locking up atmospheric carbon dioxide in the ocean.
In the study, Scripps scientists have pinpointed a bacterium that appears to play a dominant role in carbon consumption. Scripps's Byron Pedler, Lihini Aluwihare, and Farooq Azam found that a single bacterium called Alteromonas could consume as much dissolved organic carbon as a diverse community of organisms.
Pedler said that this was a surprising result because this pool of carbon is comprised of an extremely diverse set of molecules, we believed that many different microbes with complementary abilities would be required to breakdown this material, but it appears that individual species may be pulling more weight than others when it comes to carbon cycling.
The study has been published in the Proceedings of the National Academy of Sciences.