Relationship between glass transition temperature, and desiccation and heat tolerance in Salmonella enterica.
Pathogenic bacteria such as Salmonella enterica exhibit high desiccation tolerance, enabling long-term survival in low water activity (aw) environments. Although there are many reports on the effects of low aw on bacterial survival, the mechanism by which bacteria acquire desiccation tolerance and r...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2020-01-01
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| Series: | PLoS ONE |
| Online Access: | https://doi.org/10.1371/journal.pone.0233638 |
| _version_ | 1819020944132276224 |
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| author | Kyeongmin Lee Masaki Shoda Kiyoshi Kawai Shigenobu Koseki |
| author_facet | Kyeongmin Lee Masaki Shoda Kiyoshi Kawai Shigenobu Koseki |
| author_sort | Kyeongmin Lee |
| collection | DOAJ |
| description | Pathogenic bacteria such as Salmonella enterica exhibit high desiccation tolerance, enabling long-term survival in low water activity (aw) environments. Although there are many reports on the effects of low aw on bacterial survival, the mechanism by which bacteria acquire desiccation tolerance and resistance to heat inactivation in low-aw foods remains unclear. We focused on the glass transition phenomenon, as bacteria may acquire environmental tolerance by state change due to glass transition. In this study, we determined the glass transition temperature (Tg) in S. enterica serovars under different aw conditions using thermal rheological analysis (TRA). The softening behaviour associated with the state change of bacterial cells was confirmed by TRA, and Tg was determined from the softening behaviour. Tg increased as the aw decreased in all S. enterica serovars. For example, while the Tg of five S. enterica serovars was determined as 35.16°C to 57.46°C at 0.87 aw, the Tg of all the five serovars increased by 77.10°C to 83.30°C at 0.43 aw. Furthermore, to verify the thermal tolerance of bacterial cells, a thermal inactivation assay was conducted at 60°C for 10 min under each aw condition. A higher survival ratio was observed as aw decreased; this represented an increase in Tg for Salmonella strains. These results suggest that the glass transition phenomenon of bacterial cells would associate with environmental tolerance. |
| first_indexed | 2024-12-21T03:59:15Z |
| format | Article |
| id | doaj.art-65a9c354ef8a4208b13d36ebdbb00e6e |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-21T03:59:15Z |
| publishDate | 2020-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-65a9c354ef8a4208b13d36ebdbb00e6e2022-12-21T19:16:45ZengPublic Library of Science (PLoS)PLoS ONE1932-62032020-01-01155e023363810.1371/journal.pone.0233638Relationship between glass transition temperature, and desiccation and heat tolerance in Salmonella enterica.Kyeongmin LeeMasaki ShodaKiyoshi KawaiShigenobu KosekiPathogenic bacteria such as Salmonella enterica exhibit high desiccation tolerance, enabling long-term survival in low water activity (aw) environments. Although there are many reports on the effects of low aw on bacterial survival, the mechanism by which bacteria acquire desiccation tolerance and resistance to heat inactivation in low-aw foods remains unclear. We focused on the glass transition phenomenon, as bacteria may acquire environmental tolerance by state change due to glass transition. In this study, we determined the glass transition temperature (Tg) in S. enterica serovars under different aw conditions using thermal rheological analysis (TRA). The softening behaviour associated with the state change of bacterial cells was confirmed by TRA, and Tg was determined from the softening behaviour. Tg increased as the aw decreased in all S. enterica serovars. For example, while the Tg of five S. enterica serovars was determined as 35.16°C to 57.46°C at 0.87 aw, the Tg of all the five serovars increased by 77.10°C to 83.30°C at 0.43 aw. Furthermore, to verify the thermal tolerance of bacterial cells, a thermal inactivation assay was conducted at 60°C for 10 min under each aw condition. A higher survival ratio was observed as aw decreased; this represented an increase in Tg for Salmonella strains. These results suggest that the glass transition phenomenon of bacterial cells would associate with environmental tolerance.https://doi.org/10.1371/journal.pone.0233638 |
| spellingShingle | Kyeongmin Lee Masaki Shoda Kiyoshi Kawai Shigenobu Koseki Relationship between glass transition temperature, and desiccation and heat tolerance in Salmonella enterica. PLoS ONE |
| title | Relationship between glass transition temperature, and desiccation and heat tolerance in Salmonella enterica. |
| title_full | Relationship between glass transition temperature, and desiccation and heat tolerance in Salmonella enterica. |
| title_fullStr | Relationship between glass transition temperature, and desiccation and heat tolerance in Salmonella enterica. |
| title_full_unstemmed | Relationship between glass transition temperature, and desiccation and heat tolerance in Salmonella enterica. |
| title_short | Relationship between glass transition temperature, and desiccation and heat tolerance in Salmonella enterica. |
| title_sort | relationship between glass transition temperature and desiccation and heat tolerance in salmonella enterica |
| url | https://doi.org/10.1371/journal.pone.0233638 |
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