Con- mutants: class of mutants in Escherichia coli K 12 lacking a major cell wall protein and defective in conjugation and adsorption of a bacteriophage

Abstract

A new class of mutants of E. coli K 12 defective in conjugation (Con- mutants) is described. They lack a major protein of the outer membrane and are defective as recipients with Hfr and F' donors and as recipients for several F like R factors and Col factors. In the case of crosses with an Hfr donor, it is shown that the Con- recipient is defective in pair formation. The mutants are resistant to certain phages due to loss of receptor activity.