Fuelling the future with photosynthesis, by Patrick Mahony, CSIRO Science by Email
Photosynthesis is the process where plants use light energy to make their food. It is important for the planet in many ways. For example, through this process oxygen gas is produced. Could this fundamental process also have other environmental benefits?
Researchers have modified photosynthesis to produce hydrogen gas. In regular photosynthesis, light energy is used to energise electrons. The electrons are then passed along transport chains to an enzyme which combines a hydrogen ion and chemical to produce a compound used to make plant food.
The scientists replaced that enzyme with hydrogenase. Instead of using the electrons to make plant food, hydrogenase combines electrons with hydrogen ions to produce hydrogen gas.
Why is hydrogen gas useful? It could be used as an alternative fuel source. Fossil fuels such as petrol and coal produce the greenhouse gas carbon dioxide when they combust, as well as other pollutants such as particulates. When hydrogen combusts with oxygen they produce water vapour. This mix doesn’t produce the other pollutants of fossil fuels, so it is a cleaner form of energy.