Furthermore, biofilm formation migh

Furthermore, biofilm formation might be enhanced by low pH
through its effect on quorum sensing (cell-to-cell signaling). There
is a general concept that changes in pH may influence many
physiological parameters which trigger numerous signaling
substances. These substances could contribute to the overall acid
tolerance response and promote biofilm formation, which is known
as an adaptation to external stressful environments. Quorum
sensing was intensively studied to regulate biofilm formation, but
signaling substances are not yet identified. The detailed role of pH
in influencing quorum sensing is still unclear. In a recent research
article on Salmonella typhimurium, pH was found to affect the
activity of two tested agfD (thin aggregative fimbriae) promoters
responsible for the regulation of multicellular and aggregative
behavior of this species (Gerstel & Romling, 2001).