Team:CIDEB-UANL Mexico/project resistance

Because our project is a biofilter which allows to remove salt from water, the bacteria needs to survive to extreme environmental conditions which normally it can’t do. We need E. Coli to survive a high salinity environment to allow it to capture sodium ions and to remove the salt concentration of the water. In order to accomplish our project goal, we have to change E. Coli metabolism and make it stronger, more resistant and more efficient than in normal E.coli bacteria.

Last discoveries show irrE as a protein capable of change the E. Coli metabolism, and giving it the ability to survive to bigger temperatures, bigger UV rays radiation and bigger salt concentration (UCL, 2012).

What does irrE do?

The protein irrE originates from Deinococcusradiodurans, and initially, this gene provides resistance to radiation. But when transformed in E. Coli, it protects it against salt, oxidative and thermal shock. (UCL, 2012) Also, different experiments from different iGEM teams, support the idea of the bigger salt resistance in E. Coli with this biobrick.

How it works?

irrE has been demonstrated to up regulate transcription of recA and pprA - genes which encode Recombines A and Radiation Inducible Protein. With respect to salt tolerance, irrE up regulates the production of several stress responsive proteins, protein kinases, metabolic proteins, and detoxification proteins. It also down regulates glycerol degradation. With this global regulatory effect, E. Coli becomes more salt tolerant (UCL, 2012).

How it is composed?

Initially, IrrE and L2+AIDA, protein for binding silica (Union module ), were joined together in only one circuit, but we needed to separate them becauseL2+AIDA has not been proved yet and it could affect the correct production of IrrE (see image 3).

Other teams that used it:

UCL 2012: They propose to confer salt tolerance on E. Coli by linking the salt tolerance gene encoding the protein irrE (BBa_K729001) to a constitutive promoter (BBa_J23119).

irrE's parts description :

Bibliography