Selection of Sucrose-Dependent <i>Escherichia coli</i> To Obtain Envelope Mutants and Fragile Cultures

Abstract

Mutants isolated as sucrose-dependent include many with apparent envelope defects, which fact often leads to filamentous growth or lysis in the absence of sucrose. One mutant can grow exponentially in 4 percent sucrose, but is very fragile: it releases all of its RNA and soluble protein when treated with 0.5 percent sodium deoxycholate. These characteristics permit the study of unstable structures and rapid processes in actively growing cells.