Part Stability

The standard conditions for E. coli growing are 37°C and 200 rpm in LB medium. Varying these conditions, in terms of salinity, pH and temperature, does the Biobrick behave in the same way?

For answering this question, the XL1 Blue strain was selected and subjected to the following unusual conditions: different salt concentrations (0% p/v, 1% p/v, 2% p/v, 3% p/v), non-usual pHs (5, 6, 7, 8) and a range of temperatures ranging from 34-44.

Results obtained:

Figure 1. Transformed XL1 Blue strain ratio GFP fluorescence/OD₅₉₅ at different concentrations of salt (NaCl). As it can be observed, Biobrick output is not substantially affected by salt concentrations.

All the salt concentrations refers to the standard composition of LB medium, i.e., 1% means 1% additional to the LB standard formulation.

Figure 2. Transformed XL1 Blue strain ratio GFP fluorescence/OD₅₉₅ at different pHs. As it can be observed, Biobrick output is not substantially affected by pH.

Figure 3. Transformed XL1 Blue strain ratio GFP fluorescence/OD₅₉₅ at different temperatures. As it can be observed, Biobrick output is affected by temperature, being higher around E. coli optimal growth temperature (37-41 °C).