title: Factors affecting tyramine production in Enterococcus durans IPLA 655.
abstract: The decarboxylation of tyrosine by certain lactic acid bacteria leads to the undesirable presence of tyramine in fermented foods. Tyramine is the most frequent biogenic amine found in cheese and is also commonly found in other fermented foods and beverages. The tyramine-producing strain Enterococcus durans IPLA 655 was grown in a bioreactor under different conditions to determine the influence of carbon source, tyrosine and tyramine concentrations, and pH on tyramine production. The carbon source appeared to have no significant effect on the production of tyramine. In contrast, tyrosine was necessary for tyramine production, while the presence of tyramine itself in the growth medium inhibited such production. pH showed by far the greatest influence on tyramine synthesis; tyramine was produced in the greatest quantities at pH 5.0, although this was accompanied by a reduced growth rate.
authors.affiliation: Instituto de Productos Lácteos de Asturias (IPLA-CSIC), Carretera de Infiesto s/n, 33300, Villaviciosa, Asturias, Spain. maag@ipla.csic.es.
authors.forename: María
authors.initials: M
authors.lastname: Fernández
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Linares
authors.forename: Ana
authors.initials: A
authors.lastname: Rodríguez
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Alvarez
mesh_terms: D001679:Biogenic Amines / Q000378:metabolism; D019149:Bioreactors / Q000382:microbiology*; D002241:Carbohydrates / Q000494:pharmacology; D003470:Culture Media / Q000494:pharmacology; D016983:Enterococcus / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000494:pharmacology; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014439:Tyramine / Q000378:metabolism*; D014443:Tyrosine / Q000494:pharmacology
chemical_list: D001679:Biogenic Amines; D002241:Carbohydrates; D003470:Culture Media; D012336:RNA, Ribosomal, 16S; D019344:Lactic Acid; D014443:Tyrosine; D014439:Tyramine