Production of the small heat shock protein Lo18 from Oenococcus oeni in Lactococcus lactis improves its stress tolerance.
Lactococcus lactis is a lactic acid bacterium widely used in cheese and fermented milk production. During fermentation, L. lactis is subjected to acid stress that impairs its growth. The small heat shock protein (sHsp) Lo18 from the acidophilic species Oenococcus oeni was expressed in L. lactis. This sHsp is known to play an important role in protein protection and membrane stabilization in O. oeni. The role of this sHsp could be studied in L. lactis, since no gene encoding for sHsp has been detected in this species. L. lactis subsp. cremoris strain MG1363 was transformed with the pDLhsp18 plasmid, which is derived from pDL278 and contains the hsp18 gene (encoding Lo18) and its own promoter sequence. The production of Lo18 during stress conditions was checked by immunoblotting and the cellular distribution of Lo18 in L. lactis cells after heat shock was determined. Our results clearly indicated a role for Lo18 in cytoplasmic protein protection and membrane stabilization during stress. The production of sHsp in L. lactis improved tolerance to heat and acid conditions in this species. Finally, the improvement of the L. lactis survival in milk medium thanks to Lo18 was highlighted, suggesting an interesting role of this sHsp. These findings suggest that the expression of a sHsp by a L. lactis strain results in greater resistance to stress, and, can consequently enhance the performances of industrial strains.
UMR A PAM Univ Bourgogne Franche-Comté - AgroSup Dijon - Equipe Vin, Aliment, Microbiologie, Stress, 21078 Dijon, cedex, France. Electronic address: stephanie.weidmann@u-bourgogne.fr.
Stéphanie
S
Weidmann
UMR A PAM Univ Bourgogne Franche-Comté - AgroSup Dijon - Equipe Vin, Aliment, Microbiologie, Stress, 21078 Dijon, cedex, France.
Magali
M
Maitre
UMR A PAM Univ Bourgogne Franche-Comté - AgroSup Dijon - Equipe Vin, Aliment, Microbiologie, Stress, 21078 Dijon, cedex, France.
Julie
J
Laurent
Univ. Lille, INRA, ISA, Univ. Artois, Univ. Littoral Côte d'Opale, EA, 7394-ICV - Institut Charles Viollette, F-59000 Lille, France.
Françoise
F
Coucheney
UMR A PAM Univ Bourgogne Franche-Comté - AgroSup Dijon - Equipe Vin, Aliment, Microbiologie, Stress, 21078 Dijon, cedex, France.
Aurélie
A
Rieu
UMR A PAM Univ Bourgogne Franche-Comté - AgroSup Dijon - Equipe Vin, Aliment, Microbiologie, Stress, 21078 Dijon, cedex, France.
Jean
J
Guzzo
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D005285:Fermentation; D050888:Heat-Shock Proteins, Small / Q000235:genetics* / Q000378:metabolism*; D006358:Hot Temperature; D013294:Lactococcus lactis / Q000235:genetics / Q000502:physiology*; D056585:Oenococcus / Q000235:genetics* / Q000378:metabolism; D013312:Stress, Physiological
D001426:Bacterial Proteins; D050888:Heat-Shock Proteins, Small
Lactococcus lactis; Milk; Oenococcus oeni; Small heat shock protein (sHsp); Stress resistance