Fig. 5

Aggregation of phage in dependence on temperature. Inhibition of aggregation at low temperature. Average effective particle diameter of bacteriophages in 37 °C (full points) in comparison to 4 °C (empty circles). The curve of a square-root function–the best fit for data measured at 37 °C—suggests a diffusion process being involved in the phage-aggregation progression. Dashed curve, fitting the measured particle dimensions under an inhibitory temperature, shows low starting value of particles’ size and much slower increase throughout timescale of the experiment (empty circles). Vertical line after time point ‘300 min’, indicates the addition of concentrated salt to previously formed aggregates to test reversibility of the aggregated state, triggered by high ionic strength. Please note a dramatic drop of average particle size at high salt (right part of the image, between time-points 300 and 360 min). Dispersion was noticed not only population of phage aggregated at 37 °C, but also in the less aggregated population at 4 °C, speaking for dispersion of clusters into individual phage particles in high ionic strength thus demonstrated the reversibility of the whole process, at both temperatures