Por favor, use este identificador para citar o enlazar a este item:
http://hdl.handle.net/10261/51415
COMPARTIR / EXPORTAR:
SHARE CORE BASE | |
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL | DATACITE | |
Título: | Contribution of the CesR-regulated genes llmg0169 and llmg2164-2163 to Lactococcus lactis fitness |
Autor: | Roces, Clara CSIC ORCID; Campelo, Ana B. CSIC; Veiga, Patrick; Pinto, João P. C.; Rodríguez González, Ana CSIC ORCID; Martínez Fernández, Beatriz CSIC ORCID | Palabras clave: | Dairy starters Lactococcus lactis Stress response Strain fitness CesSR |
Fecha de publicación: | 15-ago-2009 | Editor: | Elsevier | Citación: | International Journal of Food Microbiology 133(3): 279-285 (2009) | Resumen: | Lactococcus lactis is one of the main components of the starter cultures used in cheese manufacture. As starter, L. lactis must tolerate harsh conditions encountered either during their production in bulk quantities or during dairy products processing. To face these hostile conditions, bacteria monitor the environment and respond by modifying gene expression appropriately. Previous transcriptomic studies showed that the two component system CesSR is the main pathway that triggers the cell envelope stress response in L. lactis treated with lactococcin 972 (Lcn972), a cell wall synthesis inhibiting bacteriocin. Among the CesR-regulated genes, llmg0169 and the operon llmg2164-2163, encoding proteins of unknown function, are among the highest up-regulated genes after activation of CesSR. In this study, we have assessed the contribution of these genes to the survival of L. lactis to different technologically-relevant stresses. Overexpressing and knock-out mutants of the genes were generated and their viability to low pH, heat, freeze-drying, presence of NaCl, cell wall antimicrobials and lytic phages attack was compared to the wild type strain. The genes llmg0169 and llmg2164-2163 contributed differently to L. lactis fitness. L. lactis Δllmg0169 was very sensitive to heat treatment while L. lactis Δllmg2164 was more sensitive to NaCl. Absence of both genes also compromised viability at low pH. On the contrary, higher expression levels of llmg0169 and llmg2164-2163, up to 26- and 14-fold increase determined by qRT-PCR, respectively, did not enhance L. lactis survival in any of the above stressful conditions (heat, pH and NaCl) or after freeze-drying. All the mutants displayed a similar phage susceptibility profile. Overexpression of llmg2164-2163 seemed to specifically protect L. lactis against the bacteriocin Lcn972 but not against other cell wall active antimicrobials. Based on our phenotypic analysis, the investigated genes are required to mount a proper response to guarantee survival of L. lactis under technologically-relevant stresses and their functionality could be a useful marker to select robust dairy starters. © 2009 Elsevier B.V. All rights reserved. | Descripción: | Este artículo forma parte de la tesis de clara Roces. Mecanismos moleculares de respuesta al estrés sobre la pared celular en Lactococcus lactis. http://hdl.handle.net/10261/109851 | URI: | http://hdl.handle.net/10261/51415 | DOI: | 10.1016/j.ijfoodmicro.2009.06.002 | Identificadores: | doi: 10.1016/j.ijfoodmicro.2009.06.002 issn: 0168-1605 |
Aparece en las colecciones: | (IPLA) Artículos |
Ficheros en este ítem:
Fichero | Descripción | Tamaño | Formato | |
---|---|---|---|---|
CesR-regulated.pdf | 227,61 kB | Adobe PDF | Visualizar/Abrir |
CORE Recommender
SCOPUSTM
Citations
13
checked on 24-abr-2024
WEB OF SCIENCETM
Citations
15
checked on 29-feb-2024
Page view(s)
350
checked on 24-abr-2024
Download(s)
288
checked on 24-abr-2024
Google ScholarTM
Check
Altmetric
Altmetric
NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.