Solar energy is the most abundant form of energy on earth, but is extremely hard to use. Thus scientists have been trying different methods to convert solar energy to chemical energy. To transfer light to allow sustainable production of chemicals motivates the development of artificial photosynthetic systems. Two main problems to be solved in this system are the electron transport media and enzymes to harvest excited electrons. The current transportation method either requires expensive semiconductor nanoparticles or special species which are inconvenient for gene operation.
What’s more, for downstream enzymes that harvest electrons, including hydrogenase and nitrogenase, we found that they are generally oxygen-intolerant. So we also want to build an oxygen-isolation system.
This year we managed to solve all the problems mentioned above once and forever in synthetic biology. Our project proposes a new method to construct an artificial photosynthetic system in model organism E.coli with the help of metal-binding proteins and surface display machinery. In addition, using silicon encapsulation, we overcome oxygen intolerance barriers of enzymes with assistance from polymer materials.
To test the efficiency of our artificial photosynthetic system and silicon encapsulation method, we use hydrogen production as an example. We successfully achieve aerobic hydrogen production using E.coli hydrogenase 1 under normal conditions. What is really exciting as that our new light-driven system can also be extended to more model species including yeast and bacillus, so do the encapsulation system!