Chapter 23 : Unveiling Prochlorococcus

Abstract:

This chapter talks about the life and times of the ocean’s smallest photosynthetic cell. The author says that it is difficult to describe the thrill of studying Prochlorococcus. Like most scientific advances, the unveiling of Prochlorococcus involved new technologies, diverse approaches, teamwork, and luck. It became clear immediately that although they shared the "signature" characteristics of Prochlorococcus, MED4 and SS120 were not the same: MED4 could grow at high light intensities that killed SS120, while SS120 could grow under extremely low-light conditions that could not sustain MED4; i.e., the cells were adapted to the light intensities found where they were captured. For every cell that is produced, there is another that is eaten by small predatory cells that must rely on others for their food. This keeps the Prochlorococcus population in check and begins the flow of energy through the marine food web. Since they reproduce by making identical copies of themselves, we know that at any moment in time there must be lineages of identical Prochlorococcus cells in the oceans. Prochlorococcus can photosynthesize, and thrive through diversity, and their federation can adapt.