iGEM Tokyo Tech 2011 Team

Rock-Paper-Scissors game

We have constructed a system of three different genetically engineered E. coli which can express each one different signaling molecule, namely, Auto Inducer 2 (AI-2), C6-HSL and C12-HSL. On the other hand we have built a separate genetically engineered E. coli which has an AND gate that can recognize each of the three signaling molecules mentioned before, and also three more signals: IPTG, arabinose (ara) and anhydrotetracyclin (aTc). When isolating one of the signal molecule-expressing E.coli and transferring it where the AND gate construct is present, the AND gate can produce an output by further adding either ara, aTc or IPTG. This system can be used to play the game Rock-Paper-Scissors between humans and E. coli.

Isoprene Synthesis

There are many places in the world where rainfalls are needed but do not occur naturally. To cause rainfalls in such places, cloud seeding can be done by using condensation nuclei (CCNs). CNNs are small particles about which could droplets coalesce; terpenes, which are chemical compounds that are naturally released by trees in tropical rain forests, are known to act like CNNs. The simplest of all terpenes is isoprene, and it can be synthetized from dimethylallyl pyrophosphate (DMAPP). DMAPP is naturally produced by E. coli, so inducing the expression of the genes that code for isoprene synthase in E. coli will result in the production of isoprene. Thus, this genetically engineered E. coli can be used to do cloud seeding.

Urea Cooler

Inspired by the energy shortage that Japan is suffering due to the Eastern Japan Great Earthquake Disaster, we have designed an energy-wise cooler based on a urea-synthetizing E. coli. This “urea cooler” makes use of the fact that urea is a heat-absorbing substance when dissolved in water (-57.8 cal/g). Since E. coli produces all the enzymes needed for urea synthesis except arginase, we will genetically introduce the genes that code for this enzyme in E. coli to achieve urea production. Arginase catalyzes the production of urea and ornithine from arginine. Releasing the resultant urea should decrease the temperature of the surrounding environment.