Minimal Medium Recovery of Heated Salmonella typhimurium LT2

Abstract

SUMMARY: Exponential phase Salmonella typhimurium lt2, S. thompson and S. heidelberg grown in a glucose-salts medium (M-9), harvested at 37°C and heat-treated at 50°C exhibit a higher recovery on M-9 agar than on Trypticase Soy agar with yeast extract. This phenomenon is analogous to minimal medium recovery of irradiated bacteria. Supplementation of M-9 agar with yeast extract or Casamino acids resulted in lower viable counts of heat-treated bacteria than on M-9 agar alone. Heat-treated bacteria incubated at 37°C in M-9 broth or distilled water recovered their ability to grow on TSY agar. This recovery is inhibited by hydroxyurea.