Inorganic salts and intracellular polyphosphate inclusions play a role in the thermotolerance of the immunobiotic Lactobacillus rhamnosus CRL 1505.
In this work, the thermotolerance of Lactobacillus rhamnosus CRL1505, an immunobiotic strain, was studied as a way to improve the tolerance of the strain to industrial processes involving heat stress. The strain displayed a high intrinsic thermotolerance (55°C, 20 min); however, after 5 min at 60°C...
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2017-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC5464658?pdf=render |
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| author | María A Correa Deza Mariana Grillo-Puertas Susana Salva Viviana A Rapisarda Carla L Gerez Graciela Font de Valdez |
| author_facet | María A Correa Deza Mariana Grillo-Puertas Susana Salva Viviana A Rapisarda Carla L Gerez Graciela Font de Valdez |
| author_sort | María A Correa Deza |
| collection | DOAJ |
| description | In this work, the thermotolerance of Lactobacillus rhamnosus CRL1505, an immunobiotic strain, was studied as a way to improve the tolerance of the strain to industrial processes involving heat stress. The strain displayed a high intrinsic thermotolerance (55°C, 20 min); however, after 5 min at 60°C in phosphate buffer a two log units decrease in cell viability was observed. Different heat shock media were tested to improve the cell survival. Best results were obtained in the mediumcontaining inorganic salts (KH2PO4, Na2HPO4, MnSO4, and MgSO4) likely as using 10% skim milk. Flow cytometry analysis evinced 25.0% live cells and a large number of injured cells (59.7%) in the inorganic salts medium after heat stress. The morphological changes caused by temperature were visualized by transmission electronic microscopy (TEM). In addition, TEM observations revealed the presence of polyphosphate (polyP) granules in the cells under no-stress conditions. A DAPI-based fluorescence technique, adjusted to Gram-positive bacteria for the first time, was used to determine intracellular polyP levels. Results obtained suggest that the high initial polyP content in L. rhamnosus CRL 1505 together with the presence of inorganic salts in the heat shock medium improve the tolerance of the cells to heat shock. To our knowledge, this is the first report giving evidence of the relationship between polyP and inorganic salts in thermotolerance of lactic acid bacteria. |
| first_indexed | 2024-12-21T14:01:02Z |
| format | Article |
| id | doaj.art-493bb2c370d345acbf7c013fdd01a977 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-21T14:01:02Z |
| publishDate | 2017-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-493bb2c370d345acbf7c013fdd01a9772022-12-21T19:01:21ZengPublic Library of Science (PLoS)PLoS ONE1932-62032017-01-01126e017924210.1371/journal.pone.0179242Inorganic salts and intracellular polyphosphate inclusions play a role in the thermotolerance of the immunobiotic Lactobacillus rhamnosus CRL 1505.María A Correa DezaMariana Grillo-PuertasSusana SalvaViviana A RapisardaCarla L GerezGraciela Font de ValdezIn this work, the thermotolerance of Lactobacillus rhamnosus CRL1505, an immunobiotic strain, was studied as a way to improve the tolerance of the strain to industrial processes involving heat stress. The strain displayed a high intrinsic thermotolerance (55°C, 20 min); however, after 5 min at 60°C in phosphate buffer a two log units decrease in cell viability was observed. Different heat shock media were tested to improve the cell survival. Best results were obtained in the mediumcontaining inorganic salts (KH2PO4, Na2HPO4, MnSO4, and MgSO4) likely as using 10% skim milk. Flow cytometry analysis evinced 25.0% live cells and a large number of injured cells (59.7%) in the inorganic salts medium after heat stress. The morphological changes caused by temperature were visualized by transmission electronic microscopy (TEM). In addition, TEM observations revealed the presence of polyphosphate (polyP) granules in the cells under no-stress conditions. A DAPI-based fluorescence technique, adjusted to Gram-positive bacteria for the first time, was used to determine intracellular polyP levels. Results obtained suggest that the high initial polyP content in L. rhamnosus CRL 1505 together with the presence of inorganic salts in the heat shock medium improve the tolerance of the cells to heat shock. To our knowledge, this is the first report giving evidence of the relationship between polyP and inorganic salts in thermotolerance of lactic acid bacteria.http://europepmc.org/articles/PMC5464658?pdf=render |
| spellingShingle | María A Correa Deza Mariana Grillo-Puertas Susana Salva Viviana A Rapisarda Carla L Gerez Graciela Font de Valdez Inorganic salts and intracellular polyphosphate inclusions play a role in the thermotolerance of the immunobiotic Lactobacillus rhamnosus CRL 1505. PLoS ONE |
| title | Inorganic salts and intracellular polyphosphate inclusions play a role in the thermotolerance of the immunobiotic Lactobacillus rhamnosus CRL 1505. |
| title_full | Inorganic salts and intracellular polyphosphate inclusions play a role in the thermotolerance of the immunobiotic Lactobacillus rhamnosus CRL 1505. |
| title_fullStr | Inorganic salts and intracellular polyphosphate inclusions play a role in the thermotolerance of the immunobiotic Lactobacillus rhamnosus CRL 1505. |
| title_full_unstemmed | Inorganic salts and intracellular polyphosphate inclusions play a role in the thermotolerance of the immunobiotic Lactobacillus rhamnosus CRL 1505. |
| title_short | Inorganic salts and intracellular polyphosphate inclusions play a role in the thermotolerance of the immunobiotic Lactobacillus rhamnosus CRL 1505. |
| title_sort | inorganic salts and intracellular polyphosphate inclusions play a role in the thermotolerance of the immunobiotic lactobacillus rhamnosus crl 1505 |
| url | http://europepmc.org/articles/PMC5464658?pdf=render |
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