EFFECT OF GLUCOSE-CONCENTRATION ON SWIMMING MOTILITY IN ENTEROBACTERIA

Since the observation that glucose prevents the synthesis of flagella in Escherichia coli was first reported in 1967, many studies have addr essed the underlying mechanism. Currently, it is thought that an incre ase in glucose concentration decreases the intracellular CRP/cAMP conc entration. This leads to an inhibitory effect on the expression of the flhD operon, the master operon for flagella synthesis. In our study o n defining factors influencing the cell differentiation of Serratia ma rcescens, glucose catabolite repression of hag expression and swimming /swarming motility was not observed. Further experiments using a simpl e swimming motility assay extended this observation to other members o f Enterobacteriaceae. Although the underlying mechanism is still uncha racterised, our results suggest that glucose catabolite repression of swimming motility may not be a common phenomenon in Enterobacteriaceae . (C) 1997 Academic Press.