title: Decarboxylase activity involved in methyl ketone production by Staphylococcus carnosus 833, a strain used in sausage fermentation.
abstract: Staphylococcus carnosus strain 833, inoculated into sausage, increased the levels of methyl ketones which contributed to the cured aroma. These ketones were predicted to arise from incomplete beta-oxidation followed by a decarboxylation. To check this hypothesis, we measured the beta-decarboxylase activity in resting cells of S. carnosus grown in complex or in synthetic medium, using as substrate a beta-ketoacid, which can be an intermediate of the beta-oxidation pathway. This activity was present throughout the growth period. The enzyme appeared to be constitutive because no induction was observed. High aeration, a pH of 5 and the presence of nitrate promoted the production of methyl ketones.
authors.affiliation: INRA Clermont Ferrand-Theix, Station de Recherches sur la Viande, 63122 Saint-Genès Champanelle, France.
authors.forename: S
authors.initials: S
authors.lastname: Fadda
authors.forename: A
authors.initials: A
authors.lastname: Lebert
authors.forename: S
authors.initials: S
authors.lastname: Leroy-Sétrin
authors.forename: R
authors.initials: R
authors.lastname: Talon
mesh_terms: D002262:Carboxy-Lyases / Q000378:metabolism*; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008461:Meat Products / Q000382:microbiology*; D009812:Odorants; D010084:Oxidation-Reduction; D010422:Pentanones / Q000378:metabolism*; D013210:Staphylococcus / Q000145:classification / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D010422:Pentanones; D002262:Carboxy-Lyases; C076402:2-pentanone; D005947:Glucose