Antibacterial activity of Lactobacillus sake isolated from meat

Abstract

A total of 221 strains of Lactobacillus isolated from meat and meat products were screened for antagonistic activities under conditions that eliminated the effects of organic acids and hydrogen peroxide. Nineteen strains of Lactobacillus sake, three strains of Lactobacillus plantarum, and one strain of Lactobacillus curvatus were shown to inhibit the growth of some other lactobacilli in an agar spot test; and cell-free supernatants from 6 of the 19 strains of L. sake exhibited inhibitory activity against indicator organisms. Comparison of the antimicrobial spectra of the supernatants suggested that the inhibitory compounds were not identical. One of the six strains, L. sake Lb 706, was chosen for further study. The compound excreted by L. sake Lb 706 was active against various lactic acid bacteria and Listeria monocytogenes. Its proteinaceous nature, narrow inhibitory spectrum, and bactericidal mode of action indicated that this substance is a bacteriocin, which we designated sakacin A. Curing experiments with two bacteriocin-producing strains of L. sake resulted in mutants that lacked both bacteriocin activity and immunity to the bacteriocin. Plasmid profile analysis of L. sake Lb 706 and two bacteriocin-negative variants of this strain indicated that a plasmid of about 18 megadaltons may be involved in the formation of bacteriocin and immunity to this antibacterial compound. In mixed culture, the bacteriocin-sensitive organisms were killed after the bacteriocin-producing strain reached maximal cell density, whereas there was no decrease in cell number in the presence of the bacteriocin-negative variant.

Genetics of bacteriocins produced by lactic acid bacteria

“…O'robutyricum, S. aureus, and Aeromonas hydrophila (see Table 3). Antagonism of food-borne pathogens by the broader-acting bacteriocins, sakacin A [166] and plantaricin S [13], is highly significant in light of a renewed interest to discover natural antimicrobials that can contribute to the safety of minimally processed foods. Given their genetic diversity, the lactobacilli continue to be the most expansive reservoir in which ncw classes of naturally occurring bacteriocins may be defined.…”

“…sake 706, has a significant spectrum of activity that includes numerous LAB and various Gram-positive pathogens ( Table 3). The genetic determinants of sakacin A production and immunity are plasmid encoded [166]. Holck et al [17] purified the bacteriocin and determined the complete amino acid sequence by Edman degradation.…”

Incidence and antibiotic susceptibility of bacteriocin‐producing lactic acid bacteria from dairy products

“…Production of CO 2 from glucose was tested MRS after 2 and 5 days at 30°C. Arginine hydrolysis was determined after 3 and 7 days at 30°C in MRS supplemented with L-arginine monochlorhydrate(Sigma, St Louis, MO, USA) at 0.3% using Nessler reagent (Schillinger and Lucke 1987;Schillinger and Lucke 1989;Tichaczek et al 1992;Schillinger et al 1993;Olasapo et al 1999;Ko & Ahn 2000;Rodriguez et al 2000). Growth in KF Streptococcus Agar (Merck) after 18 h at 45°C and in bile aesculin agar (Oxoid, Hapshire, UK) supplemented with 20 g L -1 of Ox-bile (Oxoid, Hapshire, UK) incubated at 45°C for 24 h was also examined.…”

Antiviral Potential of Selected Starter Cultures, Bacteriocins and d,l-Lactic Acid

“…The experiment was performed twice. The biological activity of the used bacteriocins was tested towards the bacteriocin-sensitive strains Listeria innocua 1 using the listeria agar as described by Con et al (2001) and Pediococcus pentosaceus 3 (both from Dr. Kroeckel, Max Rubner Institute, Kulmbach) by a well-diffusion assay according to Schillinger and Luecke (1989) (Fig. 1).…”