title: Partial characterization of a bacteriocin produced by Lactobacillus helveticus.
abstract: OBJECTIVE
  To investigate the antimicrobial activity of a strain of Lactobacillus helveticus.
  
  
  RESULTS
  The culture supernatant fluid Lact. helveticus G51 showed antimicrobial activity against thermophilic strains of Lactobacillus. Purification of the active compound was achieved after gel filtration and ion exchange chromatography. As revealed by SDS-PAGE, active fractions were relatively homogeneous, showing a protein with a molecular mass of 12.5 kDa. The antimicrobial compound was heat labile, inactivated by proteolytic enzymes and had a bactericidal mode of action.
  
  
  CONCLUSIONS
  The antimicrobial activity expressed by Lact. helveticus G51 was correlated with the production of a bacteriocin with properties that were different to other helveticins.
  
  
  CONCLUSIONS
  The study has provided further data on Lact. helveticus bacteriocins. The strong activity of the bacteriocin towards various thermophilic lactobacilli warrants further investigation for its potential to obtain attenuated cultures for the enhancement of the cheese-ripening process.
authors.affiliation: Istituto di Microbiologia, Università Cattolica del Sacro Cuore, Piacenza, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Bonadè
authors.forename: F
authors.initials: F
authors.lastname: Murelli
authors.forename: M
authors.initials: M
authors.lastname: Vescovo
authors.forename: G
authors.initials: G
authors.lastname: Scolari
mesh_terms: D001430:Bacteriocins / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology*; D002611:Cheese / Q000382:microbiology*; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000378:metabolism; D005516:Food Microbiology; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007778:Lactobacillus / Q000737:chemistry* / Q000187:drug effects* / Q000254:growth & development; D008826:Microbial Sensitivity Tests; D008970:Molecular Weight
chemical_list: D001430:Bacteriocins; D010450:Endopeptidases