Fragile cultures of Escherichia coli produced by growth in high concentrations of various salts.

Abstract

SUCROSE-DEPENDENT mutants have been reported which permit total isolation under mild conditions of cellular ribonucleic acid and proteins from actively growing cultures1. The considerable time and effort required to isolate equivalent mutants in strains of other genetic provenance had led us to search for a general method to produce fragile growing cultures. This communication reports such a technique : growth in 0.5 M sodium sulphate or comparable concentrations of other salts.