Reverse Photosynthesis Turns Plants Into Biofuels and Plastics

Reverse Photosynthesis

Researchers from the University of Copenhagen in Denmark and Chalmers University of Technology in Sweden have discovered fungi that possess a natural mechanism of "reverse photosynthesis"—enabling it to access sugars and nutrients found in other plants.

Prof. Claus Felby of the Department of Geoscience and Natural Resource Management at the University of Copenhagen says that “this is a game changer, one that could transform the industrial production of fuels and chemicals, thus serving to reduce pollution significantly.”

Prof. Felby is a senior author of the study entitled “Light-driven oxidation of polysaccharides by photosynthetic pigments and a metalloenzyme,” which was published in the journal Nature Communications.

Compared to photosynthesis, which helps build plant material from solar rays from the Sun, reverse photosynthesis breaks down that same material to get at its more fundamental nutrients.

Harnessing the Sun

The scientists explain this process as taking “a large sugar molecule to be oxidized; an enzyme called lytic polysaccharide monooxygenase, which is found in many fungi and bacteria; and some chlorophyll-containing green extract from leaves.”

“Everything is mixed in a test tube and exposed to sunlight. The biomass is then completely or partially broken down.” The process makes it easier to decompose large sugar molecules into clean energy for use in energy in ethanol production.

The term “reverse photosynthesis” was used because it makes use of solar rays and atmospheric oxygen to produce carbon bonds, rather than oxygen, the usual byproduct.

“The discovery means that by using the Sun, we can produce biofuels and biochemicals for things like plastics—faster, at lower temperatures and with enhanced energy-efficiency,” says Dr. David Cannella of the University of Copenhagen, and lead author of the study.

Using the Sun, reactions that usually take 24 hours can be completed in as little time as 10 minutes.

“Additional research and development is required before the discovery can directly benefit society, but its potential is one of the greatest we have seen in years,” says Prof. Felby.