title: Modification of the response to 8 MeV electrons of auxotrophic strains of Escherichia coli by amino-acid deprivation and rifampicin.
abstract: An investigation has been made of the possibility that the accumulation of RNA enriched in messenger can influence the survival of bacteria after exposure to 8 MeV electrons. The multiple amino-acid auxotroph E. coli CP79 RCrel accumulates RNA during inhibition of protein synthesis, and the proportion of RNA present as messenger increases by a factor of 3 during a 2-hour period of amino-acid deprivation. Amino-acid withdrawal led to changes in the shape of the survival curve, which also occurred in strain CP78 RCstr, which synthesizes very little RNA when deprived of amino acids. We conclude that accumulation of RNA enriched in messenger plays little or no part in modification of the survival of irradiated bacteria. We show that rifampicin, an inhibitor of RNA synthesis, increases the sensitivity of both strains equally.
mesh_terms: D000596:Amino Acids / Q000502:physiology*; D004583:Electrons; D004926:Escherichia coli / Q000187:drug effects / Q000528:radiation effects*; D012329:RNA, Bacterial / Q000096:biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis; D011830:Radiation Effects; D012293:Rifampin / Q000494:pharmacology*
chemical_list: D000596:Amino Acids; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012293:Rifampin