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Indole at low concentration helps exponentially growing Escherichia coli survive at high temperature
A culture of stationary phase Escherichia coli cells has been reported to produce copious indole when exposed to high temperature (50°C), and this response has been proposed to aid survival. We reinvestigated this phenomenon and found that indole production under these conditions is probably not a d...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5720752/ https://www.ncbi.nlm.nih.gov/pubmed/29216232 http://dx.doi.org/10.1371/journal.pone.0188853 |
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author | Liu, Junyan Summers, David |
author_facet | Liu, Junyan Summers, David |
author_sort | Liu, Junyan |
collection | PubMed |
description | A culture of stationary phase Escherichia coli cells has been reported to produce copious indole when exposed to high temperature (50°C), and this response has been proposed to aid survival. We reinvestigated this phenomenon and found that indole production under these conditions is probably not a direct response to heat stress. Rather, E. coli produces indole when growth is prevented, irrespective of whether this is due to heat stress, antibiotic treatment or the removal of nutrients. Moreover, 300μM indole produced at 50°C does not improve the viability of heat stressed cells. Interestingly, a much lower concentration of indole (20 μM) improves the survival of an indole-negative strain (ΔtnaA) when heat stressed during exponential growth. In addition we have shown that the distribution of tryptophanase, the enzyme responsible for indole synthesis, is highly heterogeneous among cells in a population, except during the transition between exponential and stationary phases. The observation that, despite the presence of the tryptophanase, very little indole is produced during early exponential phase suggests that there is post-translational regulation of the enzyme. |
format | Online Article Text |
id | pubmed-5720752 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-57207522017-12-15 Indole at low concentration helps exponentially growing Escherichia coli survive at high temperature Liu, Junyan Summers, David PLoS One Research Article A culture of stationary phase Escherichia coli cells has been reported to produce copious indole when exposed to high temperature (50°C), and this response has been proposed to aid survival. We reinvestigated this phenomenon and found that indole production under these conditions is probably not a direct response to heat stress. Rather, E. coli produces indole when growth is prevented, irrespective of whether this is due to heat stress, antibiotic treatment or the removal of nutrients. Moreover, 300μM indole produced at 50°C does not improve the viability of heat stressed cells. Interestingly, a much lower concentration of indole (20 μM) improves the survival of an indole-negative strain (ΔtnaA) when heat stressed during exponential growth. In addition we have shown that the distribution of tryptophanase, the enzyme responsible for indole synthesis, is highly heterogeneous among cells in a population, except during the transition between exponential and stationary phases. The observation that, despite the presence of the tryptophanase, very little indole is produced during early exponential phase suggests that there is post-translational regulation of the enzyme. Public Library of Science 2017-12-07 /pmc/articles/PMC5720752/ /pubmed/29216232 http://dx.doi.org/10.1371/journal.pone.0188853 Text en © 2017 Liu, Summers http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
spellingShingle | Research Article Liu, Junyan Summers, David Indole at low concentration helps exponentially growing Escherichia coli survive at high temperature |
title | Indole at low concentration helps exponentially growing Escherichia coli survive at high temperature |
title_full | Indole at low concentration helps exponentially growing Escherichia coli survive at high temperature |
title_fullStr | Indole at low concentration helps exponentially growing Escherichia coli survive at high temperature |
title_full_unstemmed | Indole at low concentration helps exponentially growing Escherichia coli survive at high temperature |
title_short | Indole at low concentration helps exponentially growing Escherichia coli survive at high temperature |
title_sort | indole at low concentration helps exponentially growing escherichia coli survive at high temperature |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5720752/ https://www.ncbi.nlm.nih.gov/pubmed/29216232 http://dx.doi.org/10.1371/journal.pone.0188853 |
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