Team:Edinburgh

There exist situations where:

• several enzymes are needed to produce the desired product
• these enzymes work synergistically; meaning they are best kept close together

Last year, Slovenia found a way to achieve synergy in the periplasm. This year, Edinburgh is focusing on achieving synergy outside the cell.

Our project

We will create microscopic bioreactors, which we define as scaffolds holding various enzymes which carry out reactions in the extracellular environment. Our hope is that, by combining the activity of multiple enzymes in a small space, high efficiency will be achieved. At least 4 systems are being considered:

Cell surface display

• The simplest system: use E. coli bacteria as the scaffold, and attach enzymes by cell surface display techniques.

• A modified version of the above: concentrate the enzymes on small parts of the bacterial surface, such as the flagella.

Phage display

• A radical proposal: use M13 phage as the scaffold, and attach enzymes by phage-display techniques to the pVIII coat protein.

• A modified version of the above: attach multiple such phage to small beads via the pIII protein, making a larger "reactor".

There are probably many uses for an extracellular reaction scaffold, so this technique is fairly general and could hopefully be used for many purposes, just by swapping in the correct BioBricks. As example systems, we will try to use cellulases as our enzymes of interest.

Biorefinery

While we're at it, it makes sense to create something from the sugar we will generate. This would involve creation of a biorefinery. While we have considered producing low yield, high value products, if this was the goal there would be no need to start with cellulose; one could simply start with sugar.

Therefore, it makes more sense to produce something that is needed in large quantities. The two obvious products are therefore fuel and food (not necessarily for humans; the world's 20 billion chickens need fed too).