Occurrence of nisin Z production in Lactococcus lactis BFE 1500 isolated from wara, a traditional Nigerian cheese product

• Published in: International journal of food microbiology Vol. 53; no. 2; pp. 141 - 152
• Main Authors: Olasupo, N.A, Schillinger, U, Narbad, A, Dodd, H, Holzapfel, W.H
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.12.1999; Elsevier
• Subjects: AFRICA; African fermented food; AFRIQUE; ALIMENT FERMENTE; ALIMENTOS FERMENTADOS; Amino Acid Sequence; Anti-Bacterial Agents - biosynthesis; BACILLUS CEREUS; Bacillus cereus - drug effects; Bacillus cereus - growth & development; Bacteriocins - analysis; Bacteriocins - biosynthesis; Bacteriology; Base Sequence; Biological and medical sciences; CHEESE; Cheese - microbiology; CLOSTRIDIUM BUTYRICUM; CLOSTRIDIUM PERFRINGENS; Clostridium perfringens - drug effects; Clostridium perfringens - growth & development; Conjugation, Genetic; DNA Primers - chemistry; DNA, Bacterial - chemistry; FERMENTACION; FERMENTATION; FERMENTED FOODS; Food additives; FOOD HYGIENE; Food industries; Food Microbiology; FROMAGE; Fundamental and applied biological sciences. Psychology; General aspects; HIGIENE DE LOS ALIMENTOS; HYGIENE DES ALIMENTS; LACTOCOCCUS; LACTOCOCCUS LACTIS; Lactococcus lactis - metabolism; LISTERIA MONOCYTOGENES; Listeria monocytogenes - drug effects; Listeria monocytogenes - growth & development; Microbiology; Molecular Sequence Data; NIGERIA; NISIN; Nisin - analysis; Nisin - biosynthesis; Nisin Z; NISINA; NISINE; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; PCR; Polymerase Chain Reaction; QUESO; Sequence Analysis, DNA; STAPHYLOCOCCUS AUREUS; Staphylococcus aureus - drug effects; Staphylococcus aureus - growth & development; Sucrose - metabolism; Wara; Africa; Nigeria; Wara; Lactococcus lactis; African fermented food; Nisin Z; Streptococcaceae; Nisin; Bacteriocin; Production; Bacteria; Micrococcales; Isolate; Activity spectrum; Fermented product; Traditional food stuff; Antimicrobial agent
• ISSN: 0168-1605; 1879-3460
• DOI: 10.1016/s0168-1605(99)00146-4

Screening for bacteriocin production of 500 strains of lactic acid bacteria (LAB) from various African fermented foods resulted in the detection of a bacteriocin producing Lactococcus lactis (BFE 1500) isolated from a dairy product called wara. The bacteriocin inhibited not only the closely related LAB, but also strains of Listeria monocytogenes, Listeria innocua, Clostridium butyricum, Clostridium perfringens, Bacillus cereus and Staphylococcus aureus. It was heat stable even at autoclaving temperature (121°C for 15 min) and was active over a wide pH range (2–10), but highest activity was observed in the lower pH range. The bacteriocin was inactivated by α-chymotrypsin and proteinase K, but not by other proteases. Growth kinetic assay indicated stronger growth inhibition by the bacteriocin produced by Lc. lactis BFE 1500 on L. monocytogenes WS 2250 and B. cereus DSM 2301 than with the nisin A producing strain DSM 20729. Polymerase chain reaction indicated the presence of the nisin operon in strain BFE 1500 and sequencing of its structural gene showed that Lc. lactis BFE 1500 produced the natural nisin variant, nisin Z, as indicated by the substitution of asparagine residue instead of histidine at position 27. The genetic determinants for bacteriocin production in strain BFE 1500 are located on a conjugative transposon. The ability of the bacteriocin produced by Lc. lactis BFE 1500 to inhibit a wide range of food-borne pathogens is of special interest for food safety, especially in the African environment with perennial problems of poor food hygiene.