Quantifying the heterogeneous heat response of Escherichia coli under dynamic temperatures.
J Appl Microbiol
; 108(4): 1123-35, 2010 Apr.
Article
em En
| MEDLINE
| ID: mdl-19735318
ABSTRACT
AIMS:
Non-sigmoid growth curves of Escherichia coli obtained at constant temperatures near the maximum growth temperature (T(max)) were previously explained by the coexistence of two subpopulations, i.e. a stress-sensitive and a stress-resistant subpopulation. Mathematical simulations with a heterogeneous model support this hypothesis for static experiments at 45 degrees C. In this article, the behaviour of E. coli, when subjected to a linearly increasing temperature crossing T(max), is studied. METHODS ANDRESULTS:
Subpopulation dynamics are studied by culturing E. coli K12 MG1655 in brain heart infusion broth in a bioreactor. The slowly increasing temperature (degrees C h(-1)) starting from 42 degrees C results in growth up to 60 degrees C, a temperature significantly higher than the known T(max). Given some additional presumptions, mathematical simulations with the heterogeneous model can describe the dynamic experiments rather well.CONCLUSIONS:
This study further confirms the existence of a stress-resistant subpopulation and reveals the unexpected growth of E. coli at temperatures significantly higher than T(max). SIGNIFICANCE AND IMPACT OF THE STUDY The growth of the small stress-resistant subpopulation at unexpectedly high temperatures asks for a revision of currently applied models in food safety and food quality strategies.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Escherichia coli K12
/
Temperatura Alta
/
Modelos Biológicos
Idioma:
En
Revista:
J Appl Microbiol
Assunto da revista:
MICROBIOLOGIA
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Bélgica