Biocatalytic conversion of fatty acids into drop-in biofuels: Towards sustainable energy sources

Intensifying effects of global warming necessitates swift solutions for decarbonization. A big source for the increasing atmospheric CO₂ is burning of transportation fuels. Although electrification of light vehicles is an important step to reduce CO₂ emissions, carbon-based fuels will still be likely to power up heavy-duty transport, marine transport, and aviation for some time. Thus, the fastest way to decarbonize these sectors could be an immediate transition to carbon-neutral biofuels. Recently, conversion of fatty acids into hydrocarbons, as “drop-in biofuels”, is emerging as a promising alternative to fossil fuels. However, current technologies rely on energy intensive chemical methods that are not quite eco-friendly. Therefore, enzymatic conversion of fatty acids into hydrocarbons present a benign production method. In the last decade, multiple enzymes have been discovered to convert free fatty acids into alka(e)nes. Here, we introduce these enzymes with a description of the studies performed so far, especially regarding cell-free biocatalysis.