Cargando…
Specific Growth Rate Determines the Sensitivity of Escherichia coli to Lactic Acid Stress: Implications for Predictive Microbiology
This study tested the hypothesis that sensitivity of Escherichia coli to lactic acid at concentrations relevant for fermented sausages (pH 4.6, 150 mM lactic acid, a (w) = 0.92, temperature = 20 or 27°C) increases with increasing growth rate. For E. coli strain 683 cultured in TSB in chemostat or ba...
Autores principales: | , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Hindawi Publishing Corporation
2014
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4109666/ https://www.ncbi.nlm.nih.gov/pubmed/25110680 http://dx.doi.org/10.1155/2014/471317 |
_version_ | 1782327898185662464 |
---|---|
author | Lindqvist, Roland Barmark, Gunilla |
author_facet | Lindqvist, Roland Barmark, Gunilla |
author_sort | Lindqvist, Roland |
collection | PubMed |
description | This study tested the hypothesis that sensitivity of Escherichia coli to lactic acid at concentrations relevant for fermented sausages (pH 4.6, 150 mM lactic acid, a (w) = 0.92, temperature = 20 or 27°C) increases with increasing growth rate. For E. coli strain 683 cultured in TSB in chemostat or batch, subsequent inactivation rates when exposed to lactic acid stress increased with increasing growth rate at harvest. A linear relationship between growth rate at harvest and inactivation rate was found to describe both batch and chemostat cultures. The maximum difference in T(90), the estimated times for a one-log reduction, was 10 hours between bacteria harvested during the first 3 hours of batch culture, that is, at different growth rates. A 10-hour difference in T(90) would correspond to measuring inactivation at 33°C or 45°C instead of 37°C based on relationships between temperature and inactivation. At similar harvest growth rates, inactivation rates were lower for bacteria cultured at 37°C than at 15–20°C. As demonstrated for E. coli 683, culture conditions leading to variable growth rates may contribute to variable lactic acid inactivation rates. Findings emphasize the use and reporting of standardised culture conditions and can have implications for the interpretation of data when developing inactivation models. |
format | Online Article Text |
id | pubmed-4109666 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2014 |
publisher | Hindawi Publishing Corporation |
record_format | MEDLINE/PubMed |
spelling | pubmed-41096662014-08-10 Specific Growth Rate Determines the Sensitivity of Escherichia coli to Lactic Acid Stress: Implications for Predictive Microbiology Lindqvist, Roland Barmark, Gunilla Biomed Res Int Research Article This study tested the hypothesis that sensitivity of Escherichia coli to lactic acid at concentrations relevant for fermented sausages (pH 4.6, 150 mM lactic acid, a (w) = 0.92, temperature = 20 or 27°C) increases with increasing growth rate. For E. coli strain 683 cultured in TSB in chemostat or batch, subsequent inactivation rates when exposed to lactic acid stress increased with increasing growth rate at harvest. A linear relationship between growth rate at harvest and inactivation rate was found to describe both batch and chemostat cultures. The maximum difference in T(90), the estimated times for a one-log reduction, was 10 hours between bacteria harvested during the first 3 hours of batch culture, that is, at different growth rates. A 10-hour difference in T(90) would correspond to measuring inactivation at 33°C or 45°C instead of 37°C based on relationships between temperature and inactivation. At similar harvest growth rates, inactivation rates were lower for bacteria cultured at 37°C than at 15–20°C. As demonstrated for E. coli 683, culture conditions leading to variable growth rates may contribute to variable lactic acid inactivation rates. Findings emphasize the use and reporting of standardised culture conditions and can have implications for the interpretation of data when developing inactivation models. Hindawi Publishing Corporation 2014 2014-07-08 /pmc/articles/PMC4109666/ /pubmed/25110680 http://dx.doi.org/10.1155/2014/471317 Text en Copyright © 2014 R. Lindqvist and G. Barmark. https://creativecommons.org/licenses/by/3.0/ This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research Article Lindqvist, Roland Barmark, Gunilla Specific Growth Rate Determines the Sensitivity of Escherichia coli to Lactic Acid Stress: Implications for Predictive Microbiology |
title | Specific Growth Rate Determines the Sensitivity of Escherichia coli to Lactic Acid Stress: Implications for Predictive Microbiology |
title_full | Specific Growth Rate Determines the Sensitivity of Escherichia coli to Lactic Acid Stress: Implications for Predictive Microbiology |
title_fullStr | Specific Growth Rate Determines the Sensitivity of Escherichia coli to Lactic Acid Stress: Implications for Predictive Microbiology |
title_full_unstemmed | Specific Growth Rate Determines the Sensitivity of Escherichia coli to Lactic Acid Stress: Implications for Predictive Microbiology |
title_short | Specific Growth Rate Determines the Sensitivity of Escherichia coli to Lactic Acid Stress: Implications for Predictive Microbiology |
title_sort | specific growth rate determines the sensitivity of escherichia coli to lactic acid stress: implications for predictive microbiology |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4109666/ https://www.ncbi.nlm.nih.gov/pubmed/25110680 http://dx.doi.org/10.1155/2014/471317 |
work_keys_str_mv | AT lindqvistroland specificgrowthratedeterminesthesensitivityofescherichiacolitolacticacidstressimplicationsforpredictivemicrobiology AT barmarkgunilla specificgrowthratedeterminesthesensitivityofescherichiacolitolacticacidstressimplicationsforpredictivemicrobiology |