title: Degradation of alpha-pinene oxide and [2H7]-2,5,6-trimethyl-hept-(2E)-enoic acid by Pseudomonas fluorescens NCIMB 11761.
abstract: When submerged cultured Pseudomonas fluorescens NCIMB 11761 was fed-batch supplemented with alpha-pinene oxide, a rapid formation of 2,6-dimethyl-5-methylene-hept-(2Z)-enal (I) (isonovalal) was observed. Biotransformation and isomerisation of (I) to the (2E)-isomer (II) (novalal) were enhanced by Lewatit OC 1064, a macroporous polystyrene adsorbent. Accelerated isomerisation in the presence of an amino donor (glycine) at pH 7.3 pointed to a merely chemical mechanism. A maximum yield of 48 g of aldehydesl(-1) was achieved, but quantitative analysis of the volatile fraction showed that the molar conversion of the pinene oxide substrate reached no more than 67%. To fill this gap of the mass balance, the acidic fraction was isolated. It contained several compounds which suggested a beta-oxidation-like catabolism starting from 2,6-dimethyl-5-methylene-hept-(2E)-enoic acid (III) (novalic acid). Using [2H7]-2,5,6-dimethyl-hept-(2E)-enoic acid as a conversion substrate and gas chromatography coupled to atomic emission detection and mass spectrometry a degradation pathway via labelled 3,4-dimethylpentenoic and methylpropanoic acids was evidenced. This pathway may play a predominant role in isoprenoid degradation by soil bacteria.
authors.affiliation: Institut für Lebensmittelchemie, Zentrum Angewandte Chemie der Universität, Wunstorfer Strasse 14, D-30453, Hannover, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Zorn
authors.forename: F
authors.initials: F
authors.lastname: Neuser
authors.forename: R G
authors.initials: RG
authors.lastname: Berger
mesh_terms: D000447:Aldehydes / Q000378:metabolism*; D000081008:Bicyclic Monoterpenes; D002851:Chromatography, High Pressure Liquid; D005229:Fatty Acids, Monounsaturated / Q000138:chemical synthesis* / Q000378:metabolism*; D007536:Isomerism; D015394:Molecular Structure; D039821:Monoterpenes; D010084:Oxidation-Reduction; D010421:Pentanoic Acids / Q000032:analysis / Q000138:chemical synthesis* / Q000378:metabolism*; D011551:Pseudomonas fluorescens / Q000378:metabolism*; D013729:Terpenes / Q000378:metabolism*
chemical_list: C488847:2,5,6-trimethylheptenoic acid; D000447:Aldehydes; D000081008:Bicyclic Monoterpenes; D005229:Fatty Acids, Monounsaturated; D039821:Monoterpenes; D010421:Pentanoic Acids; D013729:Terpenes; C473705:isonovalal; C053997:2-pinene oxide