Antimicrobial activity of Pediococcus acidilactici PTCC ۱۹۵۴and Leuconostoc mesenteroides PTCC ۱۹۵۳ isolated from organic meatsausages

Background and Aim : Organic meat products are well known for their probiotic values due tothe presence of probiotic lactic acid bacteria such as Lactobacillus, Leuconostoc, Lactococcus, andPediococcus strains. This study aimed to isolate and characterize new strains of lactic acid bacteria(LABs) from organic meat sausages and to evaluate their antimicrobial activities.Methods : In this study, LAB strains were isolated from vacuum-packed organic meat sausagesbought from Solico Group Co Ltd. (Tehran, Iran). All isolates were characterized bymorphological, biochemical, and ۱۶S rRNA analysis. The primary antibacterial activity of theisolates was evaluated against Micrococcus luteus PTCC ۱۴۰۸. The growth kinetics andantimicrobial activity of the strain MN-B against Lactobacillus casei ATCC ۳۹۳۹۲ weredetermined in MRS broth medium. In addition, bacteriocin produced by the strains MN-B revealedantimicrobial activity against selected foodborne pathogens. Bacteriocin produced by the MN-Bstrain was partially purified using the adsorption-desorption method followed by dialyzes.Results : In this study, two Pediococcus spp. and three Leuconostoc spp. with antimicrobialactivity were isolated from vacuum-packed organic meat sausages and designated as MN-A, MNB,MN-A۲, MN-A۲-۱, and MN-A۳. The results showed that the isolate MN-A and MN-Bbelonged to the strain Pediococcus acidilactici and the MN-A۲, MN-A۲-۱, and MN-A۳ isolateswere identified as Leuconostoc mesenteroides strains. Amongst the isolates, the strain MN-Bshowed the highest antimicrobial activity against the Micrococcus luteus PTCC ۱۴۰۸. Themolecular weight of bacteriocin was about ۵.۰ KDa.Conclusion : Pediococcus acidilactici (strain MN-B) showed significant antimicrobial activityagainst Salmonella enterica subsp. enterica serotype Typhimurium PTCC ۱۷۰۹, Staphylococcusaureus PTCC ۱۱۱۳, Listeria monocytogenes PTCC۱۳۰۲, and Listeria inovani PTCC ۱۳۰۳.Therefore, this strain can be considered a potential candidate in different sectors such as the foodindustry as a preservative.

کلیدواژه ها:

Antimicrobial activity ، bacteriocin ، isolation ، characterization ،