Renewable Energy Engineered from E. Coli

In a breakthrough study, researchers have created a renewable form of energy from the bacteria E. coli.

The harmless gut bacterium yields renewable propane, and is a step towards commercial production of a fuel that could one day reduce our dependence on fossil fuels.

"Although we have only produced tiny amounts so far, the fuel we have produced is ready to be used in an engine straight away... this opens up possibilities for future sustainable production of renewable fuels that at first could complement, and thereafter replace fossil fuels like diesel, petrol, natural gas and jet fuel," Dr. Patrik Jones, from the Department of Life Sciences at Imperial College London, said in a statement.

The results of the study are published in the journal Nature Communications.

Propane is produced as a by-product during natural gas processing and petroleum refining, but both are finite resources. It's used in many applications, from central heating to camping stoves and conventional motor vehicles.

A team of scientists thought of the novel idea of converting Escherichia coli into this widely used fuel.

They achieved this by interrupting the biological process within the bacterium that turns fatty acids into cell membranes. The researchers used enzymes to channel the fatty acids along a different biological pathway, so that the bacteria made engine-ready renewable propane instead of cell membranes.

By halting this process at an early stage - using an enzyme called thioesterase - they could remove butyric acid, a compound that is an essential precursor for propane production.

Scientists chose to target propane specifically because it can easily escape the cell as a gas, yet requires little energy to transform from its natural gaseous state into a liquid that is easy to transport, store and use.

"Fossil fuels are a finite resource and as our population continues to grow we are going to have to come up with new ways to meet increasing energy demands," Jones added.

Their goal is to ultimately insert this engineered system into photosynthetic bacteria, so as to one day directly convert solar energy into chemical fuel.