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From 2010.igem.org

Sensing Results

pCaiF strength

[http://partsregistry.org/Part:BBa_K398326 BBa_K398326]

pCaiF is one of our Biobricks of the sensing project. It's function is to express proteins under glucose limitation conditions. In order to measure its strength we attached the GFP generator [http://partsregistry.org/Part:BBa_E0240 BBa_E0240] in front of this new promoter in order to know the response produced in the different growth phases.

Our results are shown in the following plots:

Different media, and carbon source concentrations were tested in order to obtain an insight about the protein production during starvation.

Also, it is well known that this promotor it's active during diauxic shifts, that's why we measured the GFP production using glucose as a first carbon source (concentration of 1g/L) and Potassium Laurate (5mM) as a secondary carbon source. The results that we got suggest that the part works like a charm! During glucose starvation high levels of cAMP can be found in cells, which enhances the expression of the proteins downstream of this promoter. On the other hand when the secondary carbon source is being catabolized by the cells, cAMP levels drop and thus the expression of genes regulated by pCaiF.

Surprisingly, we found a leaky production of GFP, however according to our treatment the GFP production during the exponential phase is lower than in the stationary phase, something expected due to the fact that the regulator of this system is the intracellular cAMP levels.

View [http://partsregistry.org/wiki/index.php?title=Part:BBa_K398326 BBa_K398326 in the parts registry]

Specified Components <partinfo>K398326 SpecifiedComponents</partinfo>

Designer: <partinfo>K398326 Designer</partinfo>

Status: <partinfo>K398326 Status</partinfo>

View [http://partsregistry.org/wiki/index.php?title=Part:BBa_K398331 BBa_K398331 in the parts registry]

Specified Components <partinfo>K398331 SpecifiedComponents</partinfo>

Designer: <partinfo>K398331 Designer</partinfo>

Status: <partinfo>K398331 Status</partinfo>