Bacterium ‘taught’ to photosynthesise
20 Jan 2016 by Evoluted New Media
Researchers have managed to induce a bacterium to perform photosynthesis.
Researchers have managed to induce a bacterium to perform photosynthesis.
Moorella thermoacetica was induced to produce acetic acid from carbon dioxide as well as synthesising semiconductor nanoparticles – cadmium sulphide - in an artificial photosynthesis system.
Peidong Yang, from Berkeley Lab's Materials Sciences Division, said: "We've demonstrated the first self-photosensitisation of a non-photosynthetic bacterium, M. thermoacetica, with cadmium sulphide nanoparticles to produce acetic acid from carbon dioxide at efficiencies and yield that are comparable to or may even exceed the capabilities of natural photosynthesis.”Photosynthesis is the process by which plants use light energy to convert carbon dioxide and water into glucose and oxygen. Artificial photosynthesis is an area being investigated by scientists for the produce of clean and sustainable production of chemicals that are currently made from petroleum.
Yang said: “We enabled the photosynthesis of acetic acid from carbon dioxide over several days of light-dark cycles at relatively high quantum yields, demonstrating a self-replicating route toward solar-to-chemical carbon dioxide reduction,” he added.
The system is self-replicating as cadmium sulphide nanoparticles in the setup serve as the ‘light harvester’ to sustain bacterial metabolism.
Cadmium sulphide is well studied for its semiconductor properties and its band structure means it is well suited for photosynthesis. It is both an electrograph – can undergo direct electron transfer from an electrode – and an acetogen, able to direct almost 90% of its photosynthetic products towards acetic acid.
“Our hybrid system combines the best of both worlds: the light-harvesting capabilities of semiconductors with the catalytic power of biology,” said Yang.
“In this study, we’ve demonstrated not only that biomaterials can be of sufficient quality to carry out useful photochemistry, but that in some ways they may be even more advantageous in biological applications.”
The paper was published in Science.
