Segregation of galactoside permease, a membrane marker during growth and cell division in Escherichia coli

Summary Incubation of Escherichia coli with chloramphenicol causes metabolic and biosynthetic disturbances, the best known of which is the synthesis of RNA and formation of incomplete ribosomes (chloramphenicol particles). As a result of the unbalanced biosynthesis the bacteria transferred in a growth medium exhibit a prolonged lag of recovery and also a lag before development of and lysis by phage 857 occurs. If lactose is the sole carbon source during incubation with chloramphenicol, the extent of these disturbaces is strongly dependent on the relative amount of -galactoside permease.This effect can serve to demonstrate heterogeneity of permease content in a population and permits to physically separate the fraction rich in permease.If bacteria fully induced for the lactose operon are grown without inducer, the permease is distributed among the progeny and unequal distribution will result in a heterogeneous population. It is shown, that using chloramphenicol treatment in the presence of lactose, followed by thermal induction of phage 857, bacteria previously deinduced during two doubling periods appear heterogeneous, about half the population being poor in permease.The significance of these results in terms of the pattern of growth of membrane is discussed.