A team of researchers led by Penn State scientists has identified the location of changes in the photosynthetic apparatus of some cyanobacteria—formerly known as "blue-green algae"—that allow the organisms to grow using far-red light. Using high-resolution cryo-electron microscopy (cryo-EM), the researchers pinpointed locations in two photosystem complexes within the cyanobacteria that incorporate alternate versions of chlorophyll pigments. These alternates are attuned to longer wavelengths, which allows the cyanobacteria to efficiently use far-red light to perform oxygen-evolving photosynthesis. Considering that the energy available in far-red light is equivalent to 15% of total solar radiation reaching Earth, this ability gives these organisms an advantage in competing with plants and other cyanobacteria for light for photosynthesis.