Bacteriophage Pf1 complex viscosity

Abstract

Bacteriophages (phages) are viruses that attack bacteria, causing them to multiply. This attack requires phage orientation with respect to the bacterial receptor, a necessary condition for attachment. Since phages are not motile, they rely on their Brownian motion and, specifically, its rotational components to reorient. We focus specifically on Pf1 (the bacteriophage called pseudomonas phage Pf1), the phage about which much has been written, though whose rotational diffusivity determined from rheological measurements is not known. We compare general rigid bead-rod theory with intramacromolecular hydrodynamic interactions with our new measurements of the complex viscosity of an aqueous Pf1 suspension to arrive at the relaxation time. From this time, we get the central transport property for the Pf1 reorientation, the dimensionless rotational diffusivity, of λ0Dr=2.37×10−6, which differs within one order of magnitude from the one from fluorescence microscopy. At low frequency, we find good agreement of our theoretical predictions with both parts of our new bacteriophage Pf1 complex viscosity measurements.