The effect of motility and cell-surface polymers on bacterial attachment.

Recently it was shown that motility of Vibrio alginolyticus facilitated cell attachment to glass surfaces. In the present study the same relationship between motility and cell attachment was confirmed for Alcaligenes and Alteromonas spp. These findings clearly answer a long-standing question: does motility facilitate attachment? However, they are contradictory to a general view on cell attachment that the energy barrier due to electrostatic repulsion between negatively charged bacterial cells and a glass surface is much greater than both the thermal kinetic energy of the bacterial cell and the bacterial swimming energy. It is shown that the energy barrier becomes far less than that usually estimated when bacterial cells are rich in polymers at their surfaces. This finding reasonably explains the dependence of bacterial attachment rate on cell motility and demands reconsideration of the mechanism of bacterial attachment.