The basic assay was as described in the previous post. She tested four strains: the wildtype parent, which expresses T4P genes and becomes moderately competent at the onset of stationary phase, a strain unable to induce its competence genes (including the T4P genes), a strain whose type 4 pilin gene is deleted, and a hypercompetent strain that expresses all the competence genes very strongly at all stages of growth.
Cultures were grown for one and two days in 2 ml of rich medium in new glass tubes, either stationary in a rack or being gently mixed on a roller wheel. Here's a photo of two of the Day 2 culture tubes, inverted to dry after staining. Most of the stationary-culture tubes had a film of cells, mainly at the bottom of the tube (exception explained below). All of the rolling-culture tubes had a bright film at the air-medium interface.
And here are the results. (Each bar is the mean of three replicate cultures.) With the exception of the stationary culture of the 'no pilin' strain, which failed to grow, all cultures gave equivalent staining intensity. There was no effect of expression of competence genes or deletion of the pilin gene.
Now I need to go back and look at the H. influenzae T4P literature, to see if this is a new result or an entirely predictable outcome.