Physiologische Bedeutung der „Stringent Control“ bei Escherichia coli unter extremen Hungerbedingungen / Stringent Control and Starvation Survival in Escherichia coli

Abstract
The viability of three isogenic relA+/relA strain pairs of Escherichia coli (CP78/CP79; NF 161/ NF162; CP 107/CP 143) was studied during prolonged starvation for amino acids, glucose or phosphate. After amino acid limitation we found a prolonged viability of all relA+ strains which synthesized ppGpp. We suggest that some ppGpp-mediated pleiotropic effects of the stringent response (e.g. glykogen accumulation, enhanced protein turnover) might be involved in this prolongation of survival. After glucose or phosphate starvation there was no difference in the relA+/relA strains either in the ppGpp content or in the survival.