title: Biotransformation of Unsaturated Long-Chain Fatty Acids by Eubacterium lentum.
abstract: Eubacterium lentum (33 strains) isomerized the 12-cis double bond of C(18) fatty acids with cis double bonds at C-9 and C-12 into an 11-trans double bond before reduction of the 9-cis double bond. The 14-cis double bond of homo-gamma-linolenic acid was isomerized by 29 strains into a 13-trans double bond. The same strains isomerized the 14-cis double bond of arachidonic acid into a 13-trans double bond and then isomerized the 8-cis double bond into a 7-trans double bond; the 13-cis double bond of 10-cis, 13-cis-nonadecadienoic acid was isomerized into a 12-trans double bond. None of these isomerization products was further reduced. Studies with resting cells showed optimal isomerization velocity at a linoleic acid concentration of 37.5 muM; higher concentrations were inhibitory. The pH optimum for isomerization was 7.5 to 8.5. The isomerase was inhibited by the sulfhydryl reagents iodoacetamide, bromoacetate, and N-ethylmaleimide and by the chelators EDTA and 1,10-phenanthroline.
authors.affiliation: Rega Institute for Medical Research, Katholieke Universiteit Leuven, B-3000 Louvain, Belgium.
authors.forename: A
authors.initials: A
authors.lastname: Verhulst
authors.forename: G
authors.initials: G
authors.lastname: Parmentier
authors.forename: G
authors.initials: G
authors.lastname: Janssen
authors.forename: S
authors.initials: S
authors.lastname: Asselberghs
authors.forename: H
authors.initials: H
authors.lastname: Eyssen