How Do Bacteria Produce Energy From Sunlight in the Deep Ocean?

Photosynthesis, the process by which oxygen and sugars are created from water and carbon dioxide using the energy of the sun, is the basis of life on earth. To perform photosynthesis in changing light conditions, living creatures were required to adapt and develop sophisticated mechanisms to collect light efficiently. To understand these mechanisms, we studied the way blue-green algae (cyanobacteria), which perform photosynthesis in the sea, adapt themselves to changing light intensities, depending on the depth of the water. We found that in deep water where there is little light, the tiny antennas through which light is collected are bigger and longer. Surprisingly, although the energy is passing through a longer pathway, it actually passes faster. We found that cyanobacteria can control the energy transfer efficiency through their light-harvesting antennas by tuning the strength by which the antenna components are coupled to each other.