Formation of the Vegetative Pool by Induced Defective and Healthy Lysogenic Strains of Escherichia coli

Abstract

Comparisons of two defective prophages carried by strains of Escherichia coli, with respect to their physiological properties following induction, has revealed that one defective mutant ([lambda] i2) can multiply normally as vegetative phage but cannot mature into normal infectious phage, whereas the other defective phage ([lambda] il) can undergo only limited multiplication since it is unstable in the vegetative stage. Consideration of the properties of [lambda] il has led to an hypothesis that induction by radiation causes production by the prophage of a vegetative replica which becomes autonomous, rather than conversion of the prophage into vegetative phage.