IGEM:PennState/2006/Progress motility
Constructs C, D, and E, which contained Construct B and constitutively expressed lacI, were built to determine the effect of increased repressor concentration on the output device. Based on the results of the assay, Construct C was the only device shown to have an effective immotile state. The pLacIQ promoter used in this construct proved to be the only promoter strong enough to produce LacI at a concentration sufficient to fully repress cell motility in the non-induced state. It was also concluded that the pKat promoter used in Construct E was strong enough to produce a less effective “off” state. This was proven by the fact that colony on the non-induced plate was noticeable smaller than the colony on the induced plate. The pCat promoter used in Construct D was not strong enough to even slightly repress the swarming phenotype in the non-induced state.