This Type of Algae Absorbs More Light for Photosynthesis Than Other Plants
by Viviane Callier/Smithsonian.com
About 2.5 billion years ago, a pigment called chlorophyll appeared in single-celled organisms, allowing them to capture energy in the form of light and convert it into sugars. This biochemical trick, called photosynthesis, transformed the biosphere. Photosynthesis later allowed plants to thrive all over the globe, and it is the basis for all food that heterotrophs—organisms that don’t produce their own food—like ourselves consume to survive.
Although the chlorophyll pigment captures short (blue) and long (red) wavelengths very well, it does not absorb the middle wavelengths of visible light as effectively. “This creates lots of untapped potential for light capture,” says Jeff Dudycha, an evolutionary biologist at the University of South Carolina. (Infrared light doesn’t have enough energy to be useful for photosynthesis, while ultraviolet light can be damaging to plants.)
But an obscure and ecologically successful group of algae, known as cryptophytes, have evolved pigments that capture light where chlorophyll cannot, Dudycha and colleagues report in a series of recent papers. The extra energy absorption from more wavelengths of light has allowed these algae to thrive in a variety of diverse environments, from oceans to streams to ponds to mud puddles.