February 09, 2017

We've just published a collaborative paper in the Journal of Bacteriology with Berenike Maier's group.  The paper sought to measure the force of retraction of type IV (TFP) of Pseudomonas aeruginosa using optical tweezers. Figure 1 from the paper is shown here, illustrating the optical tweezer's set-up used (panel a) and the force measurements of pili retraction (panel b).  The punch line from the paper is that the force of retraction of the TFP is ~30 pN, which is about 1/3 the force observed for other TFP, and that the ability of the TFP to adhere to a glass surface appears to be enhanced if that surface is coated with the Pel polysaccharide produced by some strains of P. aeruginosa.  Amy Baker, a PhD student in the lab, built a number of strains that were important for performing the reported studies.