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Pediococcus acidilactici UL 5 and L actococcus lactis ATCC 11454 are able to survive and express their bacteriocin genes under simulated gastrointestinal conditions
Author(s) -
Fernandez B.,
Hammami R.,
Savard P.,
Jean J.,
Fliss I.
Publication year - 2014
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/jam.12391
Subject(s) - pediococcus acidilactici , library science , medicine , biology , computer science , lactic acid , genetics , bacteria , lactobacillus plantarum
Aims The aim of this work is to study the expression of stress genes and those involved in pediocin and nisin production in P ediococcus acidilactici UL 5 and Lactococcus lactis ATCC 11454 under simulated gastrointestinal ( GI ) physiological conditions. Methods and Results The two strains were fed to a dynamic GI model ( TIM ‐1). Samples were taken from different compartments and analysed for strain survival as well as for the expression of pediocin PA ‐1 operon, nisin A production gene and stress genes using RT ‐q PCR . Ileal‐delivered efflux showed a survival rate of 17 and 0·0007% for P ed. acidilactici and L a. lactis , respectively. Pediocin operon genes from stressed cells were generally expressed at least at the same level as for unstressed cells. However, ped A is up‐regulated in the effluent at 120 and 180 min. Nisin A genes were always up‐regulated with particularly in the stomach after 70 min compared with control. Conclusions Bacteriocin production of P ed. acidilactici UL 5 and L c. lactis ATCC 11454 are not affected by upper GI simulated conditions and thus could be considered as relevant probiotic candidates. Significance and Impact of the Study This study demonstrates the capacity of lactic acid bacteria to survive and express their bacteriocins genes under simulated GI conditions.