Isolation of bacteriocin-producing lactic acid bacteria from meat and meat products and its spectrum of inhibitory activity

Abstract

A total of 285 samples of meat and meat products were evaluated for the presence of bacteriocin-producing lactic acid bacteria by the "sandwich" test. From 174 of these samples, 813 strains of lactic acid bacteria were isolated. They were able to inhibit the growth of Staphylococcus aureus CTC 33 and/or Listeria innocua Lin 11. When evaluated by the well-diffusion assay, 128 of these strains inhibited the growth of the indicator strains. The inhibitory spectra of activity of the isolates were evaluated against a range of Gram-positive and Gramnegative test organisms. S. aureus was the most sensitive indicator tested, whereas Enterococcus faecalis and Lactobacillus plantarum were the most resistant ones. All the compounds produced by the lactic acid bacteria were fully or partially inactivated by some of the proteolytic enzymes, which indicates their proteinaceous nature. The antimicrobial activity of the bacteriocins produced by the lactic acid bacteria isolated in this work could act as a potential barrier to inhibit the growth of spoilage bacteria and foodborne pathogens.

Quality evaluation of parmesan-type cheese: a chemometric approach

“…Pyruvate conversion by the action of lactate dehydrogenase (LDH) results in lactate that decreases pH and acts favorably in the physicochemical stabilization of the product (Monfredini et al, 2012;Bromberg et al, 2004;Ogunbanwo et al, 2003). In Parmesan-type cheeses, ripening is carried out for around six months at a temperature that should not exceed 18 °C and a relative humidity of 80%.…”

Screening of lactic acid bacteria from vacuum packaged beef for antimicrobial activity

“…The inhibitory effect observed for the other 30 LAB isolates when using the agar spot test could be attributed to the production of lactic and acetic acids and the consequent pH decrease or to the presence of hydrogen peroxide (20). Furthermore, false negative results in the well-diffusion assay for positive results in the agar spot test are possible due to aggregation, non-diffusible bacteriocins, protease inactivation and concentration effects (5,21).…”

“…The addition of LAB to meat products can improve safety and stability of the products, extending shelf life by inhibiting undesirable changes brought about by spoilage microorganisms or abiotic reactions. It can also provide modifications of the raw material to obtain new sensory properties and health benefits through positive effects on the intestinal microbiota (5,20,21). The identification of LAB that dominate the microbiota of meat is an important step in the search for potential new starter cultures and bacteriocins for meat preservation and fermentation (4,20).…”

Phenotypic characterization and species-specific PCR of promising starter culture strains of Lactobacillus plantarum isolated from naturally fermented sausages

“…The reduction of the pH by the lactic acid secreted by lactic acid bacteria is one example of these desirable changes (11). The abilities of the lactic acid bacteria, in particular lactobacilli, to reduce the pH and to produce bacteriocins prevent the growth of pathogenic and spoilage microorganisms, improving the safety and conservation of meat products (2,6,8,10,15,16,22).…”