A chance finding has led to the first new chlorophyll discovered in 67 years, opening up possibilities for biofuel and food crops to use sunlight more efficiently.

Chlorophyll is a key molecule in photosynthesis—the process by which plants harness sunlight—providing our food, our fossil fuels and the oxygen we breathe.

This new variant, chlorophyll f, was found during a study of single-celled cyanobacteria, formerly known as blue-green algae, which live in the ancient rock-like accumulations called stromatolites in Shark Bay, Western Australia.

For her contribution to our knowledge of chlorophyll and cyanobacteria, University of Sydney A/Prof Min Chen received the Science Minister’s Prize for Life Scientist of the Year in 2011.

This discovery is particularly significant for our sustainable future because chlorophyll f harvests far-red light, which is lower on the energy spectrum than visible light.

This potentially broadens the range of light that can be used for photosynthesis. Introducing chlorophyll f into crop plants would open the way to more efficient collection of energy from the sun.  It could also allow biofuel and food crops to be planted closer together, increasing overall yields.

“Finding the new chlorophyll was totally unexpected—it was one of those serendipitous moments of scientific discovery. I was actually looking for chlorophyll d, which we knew could be found in cyanobacteria living in low light conditions. I thought that stromatolites would be a good place to look, since the bacteria in the middle of the structures don’t get as much light as those on the edge,” Min says.

Min’s group is now culturing the cyanobacteria in the lab, in the hope of sequencing its genome and isolating the gene or genes responsible for chlorophyll f—which may lead the way for crop plants to one day take advantage of its benefits.

Photo: 2011 Life Scientist of the Year Min Chen.

Credit: Prime Minister’s Science Prizes/Bearcage

University of Sydney, Min Chen, min.chen@sydney.edu.au, sydney.edu.au/science/biology/about_us/academic_staff/chen_min