Induced synthesis of enzymes in bacteria analyzed at the cellular level

Abstract

Bacteriophage is utilized as a discriminating device for determining the distribution of an inducible enzyme (β-D-galactosidase) in the cells of a culture of bacteria (E. coli B). It is shown that the cellular distribution of enzyme is given by the shape of the curve of enzyme released vs number of cells lysed. This distribution is investigated in cultures induced to various levels of specific enzyme activity. Under suitable conditions of induction, it is found that the induced synthesis of β-galactosidase proceeds at a uniform rate in all the cells. Under other conditions, however, a high degree of heterogeneity may occur. When enzyme-containing cells multiply in the absence of inducer, the initially-present enzyme is uniformly partitioned among the daughter cells.