title: Detection of the bacteriocin propionicin PLG-1 with polyvalent anti-PLG-1 antiserum.
abstract: Polyclonal antibodies against the bacteriocin propionicin PLG-1 were produced in rabbits at high titer (256,000 to 512,000, as determined by indirect enzyme-linked immunosorbent assay [ELISA]). Anti-PLG-1 antiserum neutralized the antimicrobial activity of PLG-1 preparations in a well diffusion assay. Cross-reacting protein was detected using an indirect ELISA of the culture supernatant from a fed-batch fermentation of the producer strain Propionibacterium thoenii P127 within the first 24 h of incubation, but bacteriocin activity was not detected in the same culture until 217 h of incubation. Culture supernatants from 156 strains of classical dairy propionibacteria were tested by indirect ELISA at 5 and 12 days of incubation for production of cross-reacting protein and by well diffusion assay for bacteriocin activity. Cross-reacting protein was detected in 52 strains: all of the tested strains of P. thoenii, most of the strains of Propionibacterium jensenii, and a minority of the Propionibacterium acidipropionici and Propionibacterium freudenreichii strains. Of these 52 strains, only 4 strains of P. thoenii showed bacteriocin activity in a well diffusion assay. Eight bacteriocin-negative mutants of strain P127 were negative in both ELISA and well diffusion assays. Western blot analysis showed that three protein bands bound anti-PLG-1 antibodies in culture supernatants: a 9.1-kDa band that is assumed to be the PLG-1 monomer and 16.2- and 27.5-kDa bands that may be precursors, multimers, or complexes of PLG-1.
authors.affiliation: Department of Food Science and Human Nutrition, Iowa State University, Ames, IA 50011, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Leversee
authors.forename: B A
authors.initials: BA
authors.lastname: Glatz
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000276:immunology*; D001430:Bacteriocins / Q000032:analysis* / Q000276:immunology* / Q000378:metabolism; D015153:Blotting, Western; D003429:Cross Reactions; D017077:Culture Media, Conditioned; D004797:Enzyme-Linked Immunosorbent Assay; D005285:Fermentation; D015151:Immunoblotting; D009500:Neutralization Tests; D011424:Propionibacterium / Q000254:growth & development / Q000378:metabolism*; D011817:Rabbits
chemical_list: D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D001430:Bacteriocins; D017077:Culture Media, Conditioned; C079796:propionicin PLG-1