Heat resistance of viable but non-culturable Escherichia coli cells determined by differential scanning calorimetry
| Autor: | Carlos A. Gómez-Aldapa, Esmeralda Rangel-Vargas, José Roberto Villagómez Ibarra, Eva María Santos-López, Javier Castro-Rosas |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Seawater preparation Hot Temperature Microbial Viability biology Calorimetry Differential Scanning Chemistry 030106 microbiology Bacterial population Heat resistance medicine.disease_cause biology.organism_classification Microbiology 03 medical and health sciences 030104 developmental biology Differential scanning calorimetry Genetics medicine Escherichia coli Molecular Biology Bacteria |
| Zdroj: | FEMS microbiology letters. 364(19) |
| ISSN: | 1574-6968 |
| Popis: | Several reports have suggested that the viable but non-culturable (VBNC) state is a resistant form of bacterial cells that allows them to remain in a dormant form in the environment. Nevertheless, studies on the resistance of VBNC bacterial cells to ecological factors are limited, mainly because techniques that allow this type of evaluation are lacking. Differential scanning calorimetry (DSC) has been used to study the thermal resistance of culturable bacteria but has never been used to study VBNC cells. In this work, the heat resistance of Escherichia coli cells in the VBNC state was studied using the DSC technique. The VBNC state was induced in E. coli ATCC 25922 by suspending bacterial cells in artificial sea water, followed by storage at 3 ± 2°C for 110 days. Periodically, the behaviour of E. coli cells was monitored by plate counts, direct viable counts and DSC. The entire bacterial population entered the VBNC state after 110 days of storage. The results obtained with DSC suggest that the VBNC state does not confer thermal resistance to E. coli cells in the temperature range analysed here. |
| Databáze: | OpenAIRE |
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