title: Heat shock induces thermotolerance and inhibition of lysis in a lysogenic strain of Lactococcus lactis.
abstract: In this preliminary work, the heat shock response of lactic acid bacteria was investigated and characterized. Log-phase Lactococcus lactis cells pre-incubated at 40 degrees C before heat challenge at 52 degrees C for 30 min demonstrated increased thermotolerance as compared with cells pre-incubated at 30 degrees C. The response persisted for at least 60 min. Additionally, we demonstrated that: (i) the physiological expression of the heat shock response is temperature dependent; (ii) ethanol 4.0% (v/v) caused, to a lesser extent, a response similar to the heat shock; and (iii) hydrogen peroxide failed to induce a detectable response. Furthermore, we suggest that the induction of the heat shock response increases the resistance of a lysogenic strain of L. lactis, treated by mitomycin C (1.25 micrograms/ml), to lysis by the bacteriophage.
authors.affiliation: Laboratoire de Génétique Microbienne, Equipe de Toxicologie Génétique, I.R.B.A., Université de Caen, France.
authors.forename: P
authors.initials: P
authors.lastname: Boutibonnes
authors.forename: B
authors.initials: B
authors.lastname: Gillot
authors.forename: Y
authors.initials: Y
authors.lastname: Auffray
authors.forename: B
authors.initials: B
authors.lastname: Thammavongs
mesh_terms: D000431:Ethanol / Q000494:pharmacology; D005516:Food Microbiology; D006358:Hot Temperature; D006861:Hydrogen Peroxide / Q000494:pharmacology; D013294:Lactococcus lactis / Q000187:drug effects / Q000502:physiology*; D008242:Lysogeny
chemical_list: D000431:Ethanol; D006861:Hydrogen Peroxide