MACROMOLECULE SYNTHESIS IN ESCHERICHIA-COLI BB UNDER VARIOUS GROWTH-CONDITIONS

The kinetic behavior of macromolecule synthesis of E. coli during balanced growth in various media at different temperatures was investigated. Macromolecule contents per cell can be expressed as exponential functions of the specific growth rate at a given temperature. The content per cell at the zero growth rate was constant in each macromolecule component, irrespective of the growth temperature. The rate of RNA synthesis per unit weight of DNA and that of protein synthesis per unit weight of RNA were taken as efficiencies of RNA and protein synthesis, respectively; both depended on the growth rate and temperature. The efficiency of RNA synthesis was very high at a high growth rate; protein synthesis rate decreased above a certain growth rate. At the same growth rate, an increase in the growth temperature resulted in a decrease in the efficiency of RNA synthesis but an increase in that of protein synthesis.