Molecular basis of the adaption of the anchovy isolate Lactobacillus sakei CRL1756 to salted environments through a proteomic approach

CAROLINA BELFIORE; FADDA S,; RAYA, R; GRACIELA VIGNOLO,

FOOD RESEARCH INTERNATIONAL

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2012 p. 1 - 8

0963-9969

Osmotic stress triggered by high salt concentrations results in the injury of starters during food processing.The adaption of the anchovy isolate Lactobacillus sakei CRL1756 to salted environments in the presence ofosmoprotectants was analyzed by using a proteomic approach. Glycine?betaine (GB) pre-treated cells ex-posed to 1.7 M NaCl+3 mM GB showed improved adaption achieving growth after a long lag phase whilenon-proliferative cells in the salted medium without GB was observed. Comparative proteomic analyses ofthe Lactobacillus cells grown in MRS+GB exposed or not to 10% salt revealed eighteen significantly regulatedproteins. Under hypertonic stress, decreased synthesis of four glycolytic enzymes (Fba, Pgk, Gpm5, Tpi) andinduction of other two (MleS, Pox2) related to an alternative energetic pathway, were registered. Proteins re-lated to general stress response and nucleotide metabolism were up-regulated. Noticeably, the induction ofDyP-type peroxidase, involved in iron transport, detoxification and oxidative stress, was observed for thefirst time in lactic acid bacteria under osmotic constraint. Our results demonstrate that GB played a significantrole in protecting L. sakei CRL1756 against salt stress. Indeed, GB commonly found in marine fish may be usedby the starter culture cells ensuring their robustness in salted-anchovy based products.