In vitro study of beneficial properties and safety of lactic acid bacteria isolated from Portuguese fermented meat products.
Many lactic acid bacteria produce bacteriocins with a rather broad spectrum of inhibition, which could offer potential applications in food preservation. Bacteriocin production by starter cultures may bring advantage to these strains in competitive interactions with pathogenic bacteria from the food matrix. The objective of this study was to determine the safety of beneficial strains (Lactobacillus plantarum ST202Ch and ST216Ch, Enterococcus faecium ST211Ch, and Lactobacillus sakei ST22Ch, ST153Ch and ST154Ch) previously isolated from fermented meat products and characterised as bacteriocin producers. Auto-aggregation was strain-specific, and values of 28.97, 27.86 and 28.56% were recorded for L. sakei ST22Ch, ST153Ch and ST154Ch, respectively, 16.95 and 14.58% for L. plantarum ST202Ch and ST216Ch, respectively, and 12.77% for E. faecium ST211Ch. Various degrees of co-aggregation between 28.85 and 44.76% for Listeria monocytogenes 211 and 409, and between 23.60 to 34.96% for E. faecium ATCC 19443 were observed. According to the results of the diffusion method, the studied strains demonstrated susceptibility to penicillin G, ampicillin, amoxicillin, amoxicillin/clavulonic acid, imipenem, linezolid, and tetracycline. In addition, the susceptibility of the six strains to various non-antibiotic commercial drugs was examined. Production of β-galactosidase by L. sakei ST22Ch, ST153Ch and ST154Ch, L. plantarum ST202Ch and ST216Ch, and E. faecium ST211Ch was confirmed by employing sterile filter paper discs impregnated with o-nitrophenyl-β-D-galactopyranose. A statistically significant (P<0.001) inhibition of Mycobacterium tuberculosis growth by bacteriocins produced by L. plantarum ST202Ch (38.3%) and ST216Ch (48.6%), L. sakei ST153Ch (16.2%) and ST154Ch (16.1%), and E. faecium ST211Ch (21.7%) was observed. As determined by the polymerase chain reaction, the tested strains showed a low virulence gene profile.
Universidade de São Paulo, Faculdade de Ciências Farmacêuticas, Departamento de Alimentos e Nutrição Experimental, Laboratório de Microbiologia de Alimentos, Ave. Prof. Lineus Prestes 580, 05508-000, São Paulo, SP, Brazil.
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Todorov
Universidade de São Paulo, Faculdade de Ciências Farmacêuticas, Departamento de Alimentos e Nutrição Experimental, Laboratório de Microbiologia de Alimentos, Ave. Prof. Lineus Prestes 580, 05508-000, São Paulo, SP, Brazil.
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Franco
Division Molecular and Cellular Biology and Human Genetics, Faculty of Medicine and Health Sciences, University of Stellenbosch, P.O. Box 19063, 7505 Tygerberg, South Africa.
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Wiid
D000900:Anti-Bacterial Agents; D001430:Bacteriocins / Q000096:biosynthesis / Q000494:pharmacology*; D019149:Bioreactors; D024881:Drug Resistance, Bacterial; D016984:Enterococcus faecium / Q000187:drug effects; D005285:Fermentation / Q000502:physiology; D005516:Food Microbiology; D007778:Lactobacillus / Q000145:classification* / Q000302:isolation & purification / Q000472:pathogenicity; D048191:Lactiplantibacillus plantarum / Q000187:drug effects; D008089:Listeria monocytogenes / Q000187:drug effects; D008461:Meat Products / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000254:growth & development*; D011174:Portugal; D019936:Probiotics / Q000009:adverse effects / Q000494:pharmacology*; D001616:beta-Galactosidase / Q000378:metabolism
D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D001616:beta-Galactosidase
Mycobacterium tuberculosis; bacteriocins; lactic acid bacteria