Revision as of 14:44, 16 July 2009 by Vmullin (Talk | contribs)


iGEM Thought-shower

Monday 12 July

Each team member researched their own ideas for our project

Tuesday 13 July

Afternoon presentations - possible projects included

  • Bacto-Stat
  • Counterfeit Bill Detector
  • Traffic light-obedient bacteria
  • Light-induced pigment production
  • Predator prey bacteria + a parasite
  • Modelling pesticide resistance
  • Galvanotaxis
  • Wave-pulse bacteria
  • Ai2 quorum sensing system


Decided to concentrate on a pigment output. Wednesday plans involve discussing ideas for pigments, following the same meeting pattern used on Tuesday. Ideally the pigment output would be a new registery part which could then be connected to any input system

Wednesday 14 July

Brainstormed possible outputs, with a kind of bacterial printer in mind

Colour Wheels

  • Primary school style: BLUE, YELLOW, RED
  • True colour wheel: YELLOW, CYAN, MAGENTA
  • Autochrome: ORANGE, GREEN, VIOLET

Viable Pigments

  • In an ideal system, we would have lots of pathways making different coloured pigments from a common precursor. One can dream...
  • Carotenoids - RED, ORANGE, YELLOW
    • Biobricks exist for part of the system
    • apparently you can go from yellow to white (cool)
  • Pseudomons aeruginosa - RED, GREENISH/BLUE
    • Pyocyanin is greenish/blue, can be synthesized from chorismic acid, or more simply, from phenazine-1-carboxylic acid (PCA)
    • Knocking out one of the genes between PCA and pyocyanin leads to the production of a red pigment
  • Chromobacterium violacein - VIOLET, CYAN
    • Violacein is a violet pigment
    • A precursor is cyan.
    • melanin - easily attainable
    • overexpression of brown could make black?

Follow ups for tomorrow

  • Possible inputs
  • Population control
  • bacterial chlorophyll?

Thursday 15 July

Hoping to start wet work on Monday!


  • Duncan has orange and brown bacteria we can start to work with. The melanin gene has been sequence, has a restriction site we would need to remove to submit it to the registry.
  • We have the genes for violacein! And there are no internal restriction sites that would need to be removed.
  • Contacted the authors of a paper to get the genes for pyocyanin biosynthesis. Two of them have forbidden restriciton sites, so we'll need to figure out how to remove them.


  • explored the idea of using common repressor / inducer systems - arabinose, lac repressor, and tet repressor - to control pigment production
  • scourged the registry for lots of different inducible promoters

Popluation Control

  • Crispain proposed a growth control dependency pathway that would make the growth of each type of bacterium (red colour-producing, blue colour-producing, yellow colour-producing, for example) dependent on an other using HSLs