Chemical Signals and Mechanosensing in Bacterial Responses to Their Environment

Bacteria encounter different environmental conditions during the course of their growth and have developed various mechanisms to sense their environment and facilitate survival. Bacteria are known to communicate with their environment through sensing of chemical signals such as pH, ionic strength, or sensing of biological molecules, as utilized in quorum sensing [1]. However, bacteria do not solely respond to their environment by means of chemical sensing, but also respond through physical-sensing mechanisms. For instance, upon adhesion to a surface, bacteria may respond by excretion of extracellular-polymeric-substances (EPS) through a mechanism called mechanosensing, allowing them to grow in their preferred, matrix-protected biofilm mode of growth [2]. Chemical sensing of antimicrobials may further enhance EPS excretion [3]. We will now first discuss the distinction between chemical- and mechanosensing mechanisms and subsequently elaborate further on mechanosensing.