Team:Imperial College/Biobricks

This year Imperial College has added 45 new B.subtilis specific parts to the registry. In addition we sought to characterise some of these parts, including the constitutive promoter and ribosome binding site pveg-spoVG. The testing constructs we developed for this promoter-RBS combination are shown below:

The promoter and RBS combinations were characterised by measuring the expression of fluorescent proteins in B.subtilis. Cultures of B.subtilis transformed with the test constructs and non-transformed B.subtilis (control) were grown to the mid-log phase. Fluorescence and O.D.₆₀₀ were both measured using a plate reader to generate fluorescence levels of the various samples. To make this data more generic, the fluorescence data were normalized to cell number using the O.D.₆₀₀ and a calibration curve of O.D.₆₀₀ vs colony forming units, as explained in the diagram below:

This calibration curve allowed us to produce the final data as shown below. The following graph clearly shows that B.subtilis transformed with GFP and RFP BioBricks are fluorescing at the corresponding excitation and emission wavelengths.