title: Production of conjugated linoleic acid and conjugated linolenic acid isomers by Bifidobacterium species.
abstract: Conjugated linoleic acid (CLA) and conjugated linolenic acid (CLNA) isomers have attracted great interest because of their potential health benefits. Formation of CLA and CLNA takes place in the rumen during biohydrogenation. Several studies have indicated that certain types of intestinal bacteria, including bifidobacteria, are able to convert linoleic acid (LA) to CLA. The role of intestinal bacteria in the formation of CLNA isomers is largely unknown. In the present study, a screening of 36 different Bifidobacterium strains for their ability to produce CLA and CLNA from free LA and alpha-linolenic acid (LNA), respectively, was performed. The strains were grown in MRS broth, to which LA or LNA (0.5 mg ml(-1)) were added after 7 h of bacterial growth. Cultures were further incubated at 37 degrees C for 72 h. Six strains (four Bifidobacterium breve strains, a Bifidobacterium bifidum strain and a Bifidobacterium pseudolongum strain) were able to produce different CLA and CLNA isomers. Conversion percentages varied from 19.5% to 53.5% for CLA production and from 55.6% to 78.4% for CLNA production among these strains. The CLA isomers produced were further identified with Ag(+)-HPLC. LA was mainly converted to t9t11-CLA and c9t11-CLA. The main CLNA isomers were identified with GC-MS as c9t11c15-CLNA and t9t11c15-CLNA.
authors.affiliation: Department of Animal Production, Ghent University, Melle, Belgium.
authors.forename: Lara
authors.initials: L
authors.lastname: Gorissen
authors.forename: Katleen
authors.initials: K
authors.lastname: Raes
authors.forename: Stefan
authors.initials: S
authors.lastname: Weckx
authors.forename: Dirk
authors.initials: D
authors.lastname: Dannenberger
authors.forename: Frédéric
authors.initials: F
authors.lastname: Leroy
authors.forename: Luc
authors.initials: L
authors.lastname: De Vuyst
authors.forename: Stefaan
authors.initials: S
authors.lastname: De Smet
mesh_terms: D000818:Animals; D001644:Bifidobacterium / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D002417:Cattle; D002645:Chickens; D005243:Feces / Q000382:microbiology; D007422:Intestines / Q000382:microbiology; D007536:Isomerism; D044243:Linoleic Acids, Conjugated / Q000096:biosynthesis* / Q000737:chemistry; D051381:Rats; D012722:Sewage / Q000382:microbiology
chemical_list: D044243:Linoleic Acids, Conjugated; D012722:Sewage