Ageing without Reproduction and the Viability of Young Bacterial Cells at Low Temperatures

Abstract
Young cells of Escherichia coli held at 1[degree]C remained physiologically young throughout the 36-day exptl. period. Young cells of Streptococcus lactis progressively aged at 1[degree]C, having the properties of mature cells after about 1 week. The death rate of young cells of E. coli at 1[degree]C was greater than that of mature cells. Young cells of Str. lactis at 1[degree]C, possibly because of their ability to age at this temp., had greater viability than did mature cells.