Natural photosynthesis is not a very efficient way of converting carbon dioxide into components fit for human purposes. However, this status might change with a new study in which engineers have demonstrated an engineering process that would facilitate more efficient use of carbon dioxide. Further, the process might also have the potential to develop a novel way of storing energy.
The research narrates an engineering process that allows cyanobacteria to use electricity and turn the CO2 into acetate or ethylene. The technique would be a massive contribution to Biofuel Market as it may enable the production of greener fuel through carbon dioxide, which is a greenhouse gas. In addition, the approach would also provide a new way of energy storage.
Natural photosynthesis is separated into two major systems by scientists: photosystem I and photosystem II. Photosystem I consisted of light for moving electrons across the membrane, whereas Photosystem II included capturing photons by enzymes that energize electrons.
Through several tests, the team realized that system had three inherent inefficiencies. The first problem is that photosystems have overlapping absorption spectra. Secondly, oxygen produced through photosystem II is obligated to compete against carbon dioxide for the enzymes fixated on the carbon pathway. Lastly, natural photosynthesis is only capable of using light in a specified part of the solar spectrum.
To overcome these inefficiencies, the researchers designed cyanobacteria (a type of bacteria that obtains energy through photosynthesis, also known as blue-green algae) to use sunlight and an electron stream to drive carbon dioxide fixation.
More importantly, they removed the process involved within photosystem II and instead used an artificial system that functioned by attaching the modified cells onto the electrical circuit. The team discovered that when the cells were exposed to light, the cyanobacteria could supply electrons to photosystem I, allowing carbon dioxide to be converted into usable fuels such as ethylene or acetate.
The researchers added that the system would work as energy storage if a renewable source is used as the electricity source. Further, carbon dioxide could work towards producing greener fuels. Although more work is required before the technique is fully developed, the team is optimistic that the system can be scaled up and would be helpful at various levels.