Proteomic changes of Lactobacillus sakei CRL1756 upon exposure to NaCl stress

BELFIORE, C.; FADDA, S; MOZZI, F; 1.VIGNOLO G

Amsterdam

Simposio; 10th International Symposium on Lactic Acid Bacteria; 2011

Federation of European Microbiological Societies and the Nether lands Society for Microbiology

Although some lactic acid bacteria (LAB) species have become a major source of concern in aquaculturedue to its pathological significance, LAB are able to grow on fish subjected to different technologicalprocesses. Previously, Leuconostoc and Lactobacillus were identified and characterized as the maingenera present in fresh anchovies. Based on technological and safety traits and considering that salt canbe a barrier to be overcome by LAB in salted fish products Lactobacillus sakei CRL1756 was selectedfor its highly NaCl tolerance. Different osmoprotectant compounds and a proteomic approach using twodimensionalpolyacrylamide gel electrophoresis (2D PAGE) were applied to investigate the adaptiveresponse of L. sakei CRL1756 to environmental osmotic stress. Among the assayed compatible solutes,glycine-betaine showed a high stimulatory effect on L. sakei CRL1756 growth in the presence of 10%NaCl. From the 50 significantly regulated proteins identified by MALDI TOF-MS analysis, 18 spotswere differentially expressed in the presence of 10 % NaCl, these involving 11 induced proteins whilethe expression of 7 spots were decreased/repressed in presence of salt. Among the 11 induced proteins byL. sakei CRL1756, 4 over-expressed spots were related to stress response and involved in the adaptationto atypical conditions and detoxification mechanisms (ClpL ATPasa, GrpE, DnaK, Dyp) and tocarbohydrate metabolism while 4 proteins from glycolytic pathway exhibited a decreased expression,this suggesting a maintenance metabolism of L. sakei CRL1756 under NaCl stress. The transfer ofgenomic information into biological insight constitutes an important tool for the selection of welladaptedstrains