title: Nisin and lacticin 481 coproduction by Lactococcus lactis strains isolated from raw ewes' milk.
abstract: Bacteriocin-producing lactococci were isolated from raw ewes' milk samples obtained from 5 different Protected Designation of Origin Zamorano cheese manufacturers. Thirteen isolates with antimicrobial activity against Lactococcus lactis HP were selected. Eleven were identified by a PCR technique as L. lactis ssp. lactis and 2 were identified as L. lactis ssp. cremoris. They were grouped under 4 different pulsed-field gel electrophoresis patterns. The presence of structural genes of both nisin and lacticin 481 was detected in 10 L. lactis ssp. lactis isolates belonging to 2 different pulsed-field gel electrophoresis patterns. Coproduction of nisin and lacticin 481 was confirmed after semipurification by using selective indicators. The production of 2 bacteriocins by the same strain is an uncommon property, with relevance in food safety. Nisin and lacticin 481 L. lactis-producing strains might be used as adjunct cultures to the commercial starter in the manufacture of dairy products.
authors.affiliation: Departamento Tecnología de Alimentos, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Carretera de La Coruña km 7, 28040 Madrid, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Bravo
authors.forename: E
authors.initials: E
authors.lastname: Rodríguez
authors.forename: M
authors.initials: M
authors.lastname: Medina
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000096:biosynthesis* / Q000737:chemistry; D001430:Bacteriocins / Q000096:biosynthesis*; D016521:Electrophoresis, Gel, Pulsed-Field; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005838:Genotype; D013294:Lactococcus lactis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008892:Milk / Q000382:microbiology*; D008969:Molecular Sequence Data; D009561:Nisin / Q000096:biosynthesis* / Q000737:chemistry; D012756:Sheep
chemical_list: D000900:Anti-Bacterial Agents; D001430:Bacteriocins; C082508:lacticin 481; D009561:Nisin