Team:Groningen/Brainstorm/Glucose Sensing



Originally the Rainbow bacteria, we now no longer plan to use the Cre/Lox system, but rather focus on glucose sensing. This choice was made because we have no good way to control the cre/lox recombination the way we would need for glucose sensing.

The idea now is to create a bacterium that senses the outside glucose concentration and produces an inversely proportional response.


We use the MoSCoW prioritization method:

  • Must have this:
    • Response should be inversely proportional to the outside glucose concentration.
    • It should be measurable on-line (visually for example).
  • Should have this if at all possible:
    • Response should be a gradient (not just on/off).
    • Delay in the response should not exceed roughly 5-10 minutes.
    • (Model) parameters should be known or obtainable.
  • Could have this if it does not affect anything else:
    • Response should reasonably accurately follow the concentration (after a delay).
  • Won't have this now but would like in the future:
    • Expand to other metabolisms.
    • Produce something more useful than a colour.


Our bacterium would have the following components:

  • The PTS system, which is already present in ... Which organisms?
  • A promoter that hooks into the PTS system. Can be either:
    • Constitutively active, but repressed by CcpA.
    • Activated by CcpA.
  • Product behind promoter as response.
  • Degradation-tag attached to the product to increase turnover rate.


First of all we are trying to model the PTS system as is. We're looking at the following existing models:

Our attempts at using these models are available in our SVN repository.

Once we have a model of the PTS system we will try adding one or more "reactions" for the HPr phosphorylation/dephosphorylation under the influence of FBP and ATP, as this leads to HPr-ser46, which lets Ccpa bind to a cre site more easily. For the moment it is assumed that HPr and Ccpa are available in abundance.