The challenge

There is an increasing need to move away from our reliance on fossil fuels – not only are they a rapidly declining resource, the damage they are doing to our environment is irrevocably clear.

Added to that, rising oil prices and global warming mean there is a drive towards finding alternative, renewable sources of energy that will not only reduce but also counter carbon dioxide emissions, one of the major contributors to climate change.

While biofuels have been around for centuries, the availability of oil and gas has, to date, proved a much more popular and less-expensive choice.

Now, biofuels are steadily regaining popularity, with scientists exploring new and innovative ways to create a sustainable solution to our global energy needs.

What we’re doing

Synthetic biology is an emerging field of research that has the potential to create more efficient, reliable and responsible solutions to some of the world’s most pressing challenges.

This is the core focus of the Bristol BioDesign Institute (BBI), where researchers have been working in the Schools of Biochemistry and Chemistry on boosting the cellular productivity of biofuels at a fundamentally scientific level.

Collaborating with scientists from the University of Kent and Queen Mary London, the research team has developed a new way of designing entirely new synthetic protein molecules that operate within living bacterial cells called E. coli.

Using sophisticated techniques in bioengineering, the researchers have generated protein nanotubes – which are miniature tube-like structures – that assemble to form scaffolding inside the cell. Whilst some bacteria do have internal scaffolds they are not very extensive. The advantage of adding these scaffolds to bacterial cells is that they can then be used to support clusters of other protein molecules called enzymes to manufacture biofuels in the bacteria.

To make the links between the scaffolds and the enzymes— which could be thought of as bolts - the team also engineered protein-based ‘Velcro’ from first principles. In other words, the scaffold was decorated with one half of the Velcro strip and the enzymes with the other. When produced together in the cells, the scaffolds and the enzymes combine to make what are termed nanofactiories.

The team demonstrate this concept by adding two enzymes for ethanol production, which E. coli normally does not produce. In this way they were able to make this particular biofuel in the bacterium.

How it helps

By applying this new technology to enzymes used in the production of ethanol - an important biofuel - the researchers have already proven that it can significantly boost biofuel production. In the case of ethanol, the technique increased alcohol production by more than 200 per cent compared with having the enzymes alone and without the scaffold.

Professor Dek Woolfson, Director of the Bristol BioDesign Institute, said: “This is very exciting for us because until now most of our protein design work has been done in the test tube. By taking this ability to design new proteins from scratch into bacteria for the first time, we can harness the full power of biology. This could include the manufacture of protein molecules and enzymes needed to make new biofuels, drugs and so on inside cells that divide and grow quickly allowing the whole process to be scaled up massively.”

Next steps

The team is now building on this process, which it calls “protein design in the cell” or “augmented biology”, to test what might be possible in combining synthetic, or so-called de novo proteins, and living cells. The hope is that the production of biofuels, drugs molecules and biomaterials may all be improved by this technology.