The open-access journal PLos Biology presented a novel finding by a team of researchers from the Univeristy of Linnaeus, in Sweden, and colleagues from Spain, explaining how oceanic bacteria harvests light energy from sunlight by using a unique photoprotein.
“It was long thought that phytoplankton were the only organisms in the sea that could harvest the energy from sunlight for growth,” says Dr. Jarone Pinhassi, scientist in marine microbiology at Linnaeus. These microscopic planktonic organisms carry out the same chlorophyll driven photosynthesis process as green plants on land.
Marine bacteria contain a gene in their genome that encodes a new kind of light-harvesting protein: proteorhodopsin. An interesting fact is that humans have it in the retinal pigment, enabling us to see when there’s little light. Ten years after the discovery, by studying a mutational analysis in a marine bacterium, scientists discovered how proteorhodopsin works in marine bacteria. This protein allows it to survive through the process of proteorhodopsin-mediated phototrophy (the acquiring of energy from light).
“Bacteria in the surface ocean are swimming in a sea of light, and it may not be all that surprising that evolution has favored microorganisms that can use this abundant energy source,” says Pinhassi.
This discovery could lead other scientists into researching ways to use proteorhodopsin-mediated phototrophy in the future solar cells they will develop.