Osmoregulation by potassium transport in<i>Escherichia coli</i>

Abstract

Cell turgor pressure determines the extent of K+ accumulation by Escherichia coli cells. K+ influx is mediated both by a constitutive system with a low affinity for K+ (Trk) and by an inducible high affinity system (Kdp). K+ efflux is controlled by as yet unidentified but independent systems. Cell K+ concentration may be the link between growth in media of high osmolarity and the concomitant accumulation of compatible solutes such as betaine.