Genomics and Metabolism in Escherichia coli

Abstract

When did Escherichia coli attain the status of a model organism? Over many decades bio- chemical researchers used E. coli as a source of enzymes supplementing the more common sources such as rat liver, pigeon breast and spin- ach, but that practice in itself did not confer the status of model organism. A giant step was taken in 1955 when the Carnegie Institute of Washing- ton Biophysics group headed by R.B. Roberts published a large monograph reporting its own work and the work of others on the intermediary metabolism of E. coli (Roberts et al., 1955). Model organism status was gained when genetic transfer capabilities were discovered (Wollman et al., 1959; Lederberg and Tatum, 1946). In this same era, Maaloe and colleagues untangled the dynamics of E. coli cell physiology by documenting the effects of shifts in growth conditions on macromolecule synthesis (summa- rized in Maaloe and Kjeldgaard, 1966). Elucida- tion of the operon theory of regulation of gene expression (by means of a combination of bacte- rial genetics and enzyme assays; Pardee et al., 1959; Jacob and Monod, 1961) firmly established E. coli as a lead microorganism for molecular biology research. 155-chapter, and nearl