Team:UNSW Australia
About Project
When project discussions began, we immediately decided to centre our ideas around a key theme: to broaden the toolkit of synthetic biology, rather than simply applying existing tech. Put simply, we wanted to leave a legacy that would make future research and industry projects brighter and more powerful. And so we brainstormed a few novel tools, including building upon UNSW's 2015 team via pseudoknot characterisation, or creating the first voltage-sensitive promoter in bacteria. We then split up into groups to flesh out and give substance to our thoughts, eventually coming together for a debate. Unanimously we decided on our current project: to standardise outer membrane vesicles (OMVs) for use in synthetic biology projects.
So what’s an OMV? They’re secreted by some species of gram-negative bacteria, when their outer membranes pinches in and buds off; the result is a nanoscale lipid bubble being released into the environment, decorated on the outside with outer-membrane proteins, and encapsulating some periplasmic contents. Given this, OMVs can be tailored to a variety of functions, by targeting proteins either to the periplasm or outer membrane. In nature, they've been co-opted for the export of signalling messages or virulence factors, but, in contrast, synthetic biology has been slow to explore their potential. One recent paper showed that scaffolding an enzymatic cascade on and in an OMV could increase the reaction rate 23-fold, relative to the same enzymes in solution; evidently, the biotech applications of OMVs may potentially be enormous, but little research is going into them.
The barrier to applying OMVs, we feel, is that there is currently no standardised, well-characterised system for making bacteria produce and customise them. While a variety of genetic variants are known to help overproduce vesicles, their relative or even absolute production rates are not known – but to best apply OMVs to an issue, isn’t it first critical that you have an optimised system for producing them? Thus, the project of UNSW Australia is to compare and contrast the effectiveness with which different genetic factors induce OMV formation, and, in doing so, provide future researchers with an effective platform to apply them from.
To do so, we’ve set the following aims:
- To develop a simple assay to score OMV formation, e.g. on OMV size, stability, and rate of production.
- To use the assay to compare a range of genetic variants, both on their own and in combination, with regards to OMV formation.
- To use the above data to produce a strain of E. coli optimised for protein and OMV production, suitable for use in future synthetic biology projects.
And, if all works out, to demonstrate some simple applications for OMVs in solving environmental or medical issues.
In doing so, we hope to make OMVs a viable tool for use in years to come by all synthetic biologists. We’re looking forward to a productive year!
