title: Identification of beta-oxidation and thioesterase activities in Staphylococcus carnosus 833 strain.
abstract: Staphylococcus carnosus 833, inoculated into sausage meat, increased the level of methyl ketones, which contributed to the cured aroma. These ketones can arise from incomplete beta-oxidation followed by two enzymatic activities: a thioesterase and a decarboxylase. In this study we identified the beta-oxidative pathway (through the measure of 3-hydroxyacyl-CoA dehydrogenase activity) and the thioesterase activity in extracts of S. carnosus cells grown in the presence of different methyl esters. The beta-oxidative system was induced by methyl esters and highest induction was found with a 12-carbon substrate. It was specific for medium chain length fatty acyl CoA substrates. Its maximal activity was observed at the end of stationary growth phase. HPLC analyses of acyl-CoA after incubation of cell extracts with palmitoyl-CoA showed that the beta-oxidation system released preferentially long chain hydroxyacyl-CoAs, enoyl-CoAs, and acyl-CoAs. The time-course of intermediate formation indicated a precursor product relationship indicative of a model of free intermediates which could be further deacylated by a thioesterase. The thioesterase activity was enhanced when S. carnosus was grown in the presence of methyl esters with at least 12 carbons and this enzyme was specific for short chain acyl-CoAs. The maximal activity was reached at the stationary growth phase.
authors.affiliation: INRA Clermont-Ferrand, Station de Recherches sur la Viande, Saint-Genès Champanelle, France.
authors.forename: G
authors.initials: G
authors.lastname: Engelvin
authors.forename: G
authors.initials: G
authors.lastname: Feron
authors.forename: C
authors.initials: C
authors.lastname: Perrin
authors.forename: D
authors.initials: D
authors.lastname: Mollé
authors.forename: R
authors.initials: R
authors.lastname: Talon
mesh_terms: D015094:3-Hydroxyacyl CoA Dehydrogenases / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003065:Coenzyme A / Q000096:biosynthesis; D004952:Esters / Q000737:chemistry / Q000378:metabolism; D007659:Ketones / Q000378:metabolism; D009829:Oleic Acids / Q000378:metabolism; D010084:Oxidation-Reduction; D010171:Palmitoyl Coenzyme A / Q000378:metabolism; D010170:Palmitoyl-CoA Hydrolase / Q000378:metabolism*; D013210:Staphylococcus / Q000254:growth & development / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D004952:Esters; D007659:Ketones; D009829:Oleic Acids; D010171:Palmitoyl Coenzyme A; C005576:methyl oleate; D015094:3-Hydroxyacyl CoA Dehydrogenases; D010170:Palmitoyl-CoA Hydrolase; D003065:Coenzyme A