Nucleic acid and protein content of Bact . lactis aerogenes . I. Equilibrium and non-equilibrium conditions

Abstract

The variations in the size and in the RNA , DNA and protein content of cells of Bact . lactis aerogenes ( Aerobacter aerogenes ) during a growth cycle are compared with the corresponding values obtained in continuous culture. The results are discussed in terms of the economy of the cell and in particular with regard to how far the levels of RNA , DNA and protein in a growth cycle differ from equilibrium values. When non-equilibrium states occur in the growth cycle explanations are suggested for the ‘overshoot’ phenomena. The results obtained when cultures are started with cells from the logarithmic phase of the growth cycle agree more closely with the equilibrium (continuous culture) values than those obtained when inocula from 24 h glucose-exhausted cultures are used. The results emphasize the disadvantages of comparing analyses of cells from cultures sampled at arbitrarily chosen times.