Altered heat-shock response in polyamine-depleted bacteria.

A polyamine-auxotrophic mutant of E. coli was cultivated in the presence or absence of putrescine and submitted to heat shock over 3 different ranges of temperature. In all cases, protein synthetic capacity measured in comparison to that of cultures at the preshift temperature was much higher in polyamine-depleted bacteria under thermic stress. Addition of putrescine only before the shift-up was able to restore gradually normal control of the relative protein synthetic capacity.