Bacteria starved for prolonged periods develop increased protection against lethal temperatures

Abstract

A marine Vibrio sp. DW1 and two Escherichia coli strains, K165 (htpR−) and Sc122 (htpR+) were submitted to heat stress after different times of starvation. All three bacterial strains developed starvation-mediated cross protection against heat. While two hours (Vibrio sp. DW1) and 24 hours (E. coli) of starvation gave near maximal protection, prolonged periods of non-growth offered increased protection. Chloramphenicol was added, at different times of starvation, to investigate the dependence on de novo protein synthesis for survival after heat stress during prolonged starvation. An obvious de novo protein synthesis mediated induction of protection against heat stress during starvation was not found. Starvation-induced cross protection against heat may be dependent on protein synthesis in the initial phase of starvation while after prolonged starvation the continuous protection offered is suggested not to be mediated by de novo protein synthesis at these times.