DETERMINATION OF BACTERIAL COLLISION EFFICIENCIES IN A ROTATING-DISK SYSTEM

The objective of this work was to determine the probability of attachment of Pseudomonas aeruginosa to glass surfaces for a range of concentrations of a 1:1 electrolyte. This parameter, referred to as the collision efficiency, was determined by depositing cells on a rotating glass disk. Collision efficiencies ranged from 0.000 83 to 0.41 for NaCl concentrations from 10(-6) to 10(-1) M, respectively, and supported the argument that the deposition of P. aeruginosa can be limited by interaction of similarly charged electric double layers. It was also shown that transport of cells to the disk surface was comparable to that of similar-sized polystyrene latex particles, although results for both were inconsistent with theory in that the deposition decreased with increasing distance from the center of the disk. The most likely explanation was nonuniform transport of particles to the rotating disk surface arising from lateral migration.