Figure 3.

Encounters of cells with resources and other microorganisms control the timescales of viral infections of bacteria, predation by protists on bacteria, marine snow formation by coagulation of phytoplankton cells following a phytoplankton bloom, and bacterial colonization of sinking marine snow, among many other microbial interactions. (a) Bacterium–virus encounters are driven by viral diffusion and bacterial swimming. (b) Bacterium–protist encounters result from the swimming of protists and the feeding currents created by beating of their flagella. (c) Phytoplankton–phytoplankton encounters are driven by buoyancy and turbulent mixing. The colour code shows intense vorticity structures visualizing locally swirling regions in the turbulent flow. (d) Bacterium–particle encounters result from the sinking of the particle, bacterial swimming and flow-induced reorientation of the bacterial swimming trajectory. (c) Reproduced from [29] (published under CC BY-NC-ND 4.0 license). (d) Adapted from [9] (published under CC BY 4.0 license).