Researchers found how algae have the ability to survive in very low levels of light.
The algae are able to do this through a strange quantum effect, dubbed coherence, which occurs during photosynthesis, a UNSW Australia news release reported.
The function of this effect in algae is unknown, but understanding it could help lead to technological innovations such as better organic solar cells and "quantum-based electronic devices," the news release reported.
"We studied tiny single-celled algae called cryptophytes that thrive in the bottom of pools of water, or under thick ice, where very little light reaches them," senior author, Professor Paul Curmi, of the UNSW School of Physics, said in the news release.
"Most cryptophytes have a light-harvesting system where quantum coherence is present. But we have found a class of cryptophytes where it is switched off because of a genetic mutation that alters the shape of a light-harvesting protein," he said.
The finding means researchers will be able to gain insight into the roles of quantum coherence in photosynthesis by comparing two types of proteins with different organisms. This process is usually only seen under controlled laboratory conditions.
The research team was surprised to observe that the transfer of energy between molecules in the light harvesting systems of two cryptophyte species was coherent.
"The assumption is that this could increase the efficiency of photosynthesis, allowing the algae and bacteria to exist on almost no light,"Curmi said.
Once a light-harvesting protein captures sunlight it needs to get the energy to the reaction center as quickly as possible
"It was assumed the energy gets to the reaction [center] in a random fashion, like a drunk staggering home. But quantum coherence would allow the energy to test every possible pathway simultaneously before travelling via the quickest route," Curmi said.
The researchers used x-ray crystallography to look at the "crystal structure of the light-harvesting complexes from three different species of cryptophytes," the news release reported.
They found the species possessed a genetic mutation that led to the insertion of an additional amino acid, changing the structure of the protein complex and interfering with coherence.
"This shows cryptophytes have evolved an elegant but powerful genetic switch to control coherence and change the mechanisms used for light harvesting," Curmi said.
