Hydrogen Sulfide --> A Novel Energy Currency for Photosynthesis

Besides removing sulfur oxides, another great contribution of these enzymes mentioned above is storing energy inside the chemical bond of hydrogen sulfide. Sulfide-quinone reductase, or sqr, then comes into effect. Sqr is able to oxidize sulfide compounds into sulfur and release the bond energy for further favorable reaction, including nitrogen removal and carbon fixation. In photoassimilation, sqr would replace the function of photosystem II. For ordinary photosynthesis, photosystem II disassociates water and oxygen is formed subsequently. In the case of our engineered cyanobacteria, hydrogen sulfide (H2S) is oxidized and sulfur is produced. In other words, we constructed sulfur version of photosynthesis instead of traditional oxygen and water version.

The special ”CO2” infused device for cyanobacteria incubation