Engineered bacteria that can synthesize biofuels from proteins are presented in a paper published online this week in Nature Biotechnology. Though the technology is not ready for commercial use, it could provide a solution to present limitations in biofuel production.
Current biofuels are generated from plant carbohydrates or lipids but not proteins, in part because biofuel-producing microorganisms conserve proteins to use for growth.
James Liao and colleagues overcome this problem by changing metabolic pathways in E. coli. The engineered bacteria are able to efficiently remove nitrogen groups from amino acids — the building blocks of proteins — to produce alcohols, which in turn are converted into biofuels. Proteins are potentially attractive molecules to turn into fuels because proteins are produced as byproducts from current industrial processes and because proteins are more abundant than carbohydrates or lipids in some organisms such as microalgae.