Detection and characterization of a novel antibacterial substance produced by a Lactobacillus delbrueckii strain 1043

Abstract

A novel antibacterial substance produced by a strain isolated from Bulgarian yellow cheese was characterized. The producer strain was identified by molecular typing to belong to the species Lactobacillus delbrueckii, which is a rare producer of bacteriocins. The inhibitory agent was heat stable and active against lactic acid bacteria species and several food‐borne pathogens : Listeria monocytogenes, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Yersinia enterocolitica and Y. pseudotuberculosis. Its sensitivity to amylolitic enzymes and lipase suggested that a lipid and carbohydrate moiety could be important for the activity. The amino acid content of the purified bacteriocin was estimated to 29 amino acids. The bacteriocin was shown to be small (3·6–6 kDa) by three different methods : HPLC gel‐filtration, SDS‐PAGE and amino acid contents.

Lactococcin MMFII, a novel class IIa bacteriocin produced by Lactococcus lactis MMFII, isolated from a Tunisian dairy product

“…Samples were incubated for 2 h at 30³C and the pH was adjusted to 6.8. For protease-susceptibility assays, culture supernatants were incubated for 2 h with hydrolases (proteinase K, trypsine, papaine, glucoamylase, lipase, K-amylase and lysozyme) at a ¢nal concentration of 1 mg ml 31 [12]. For testing residual inhibitory activities, each sample was assayed in the agar well di¡usion test (ADT) [13].…”

Heterologous production of pediocin for the control of Listeria monocytogenes in dairy foods

“…Nisin has been shown to inhibit the growth of L. monocytogenes in several fermented dairy products (Davies, Bevis, & Delves-Broughton, 1997;Ferreira & Lund,, 1996), however, nisin-resistant strains (Gravesen, Jydegaard Axelsen, Mendes da Silva, Hansen, & Knochel, 2002;Mazzotta & Montville, 1997) have been identified suggesting a need for additional "food-grade" bacteriocins. Bacteriocins with antilisterial activity have been identified in dairy starter LAB, including Streptococcus thermophilus (Fontaine & Hols, 2008;Gilbreth & Somkuti, 2005;Marciset, Jeronimus-Stratingh, Mollet, & Poolman, 1997;Villani et al, 1995) and L. lactis (Akcelik, Tukel, Ozcengiz, & Akcelik, 2006;Elotmani, Revol-Junelles, Assobhei, & Millere, 2002;Ferchichi, Frere, Mabrouk, & Manai, 2001;Kim, Kim, Kim, & Kim, 2006;McAuliffe et al, 1998), and in non-starter LAB (NSLAB) including lactobacilli (Corr et al, 2007;Ennahar et al, 1996;Holck, Axelsson, Birkeland, Aukrust, & Blom, 1992;Miteva et al, 1998;Mueller, Carrasco, Tonarelli, & Simonetta, 2009;Tichaczek, Vogel, & Hammes, 1993) and enterococci (Franz, van Belkum, Holzapfel, Abriouel, & Galvez, 2007;Khan, Flint, & Yu, 2010;Renye, Somkuti, Paul, & Van Hekken, 2009). …”

Synthesis of a Pentasaccharide Repeating Unit of the Extracellular Polysaccharide Produced by Lactobacillus Delbrueckii Subsp. Bulgaricus 291

“…EPSs produced by LAB have several medicinal values, possessing antitumor, [2] antimutagenic, [3] antiulcer, [4] and antibacterial activities. [5] In addition, LAB have been shown to be effective as immunostimulators [6] and blood cholesterol-lowering agents. [7] It has been found that the above-mentioned medicinal events arise from the whole microorganisms or cell wall components or extracellular polysaccharides.…”