title: Bioconversion of linoleic acid into conjugated linoleic acid by immobilized Lactobacillus reuteri.
abstract: Lactobacillus reuteri was immobilized on silica gel to evaluate the bioconversion of linoleic acid (LA) into conjugated linoleic acid (CLA), consisting of cis-9,trans-11 and trans-10,cis-12 isomers. The amount of cell to carrier, the reaction time, and the substrate concentration, pH, and temperature for CLA production were optimized at 10 mg of cells/(g of carrier), 1 h, 500 mg/L LA, 10.5, and 55 degrees C, respectively. In the presence of 1.0 mM Cu(2+), CLA production increased by 110%. Under the optimal conditions, the immobilized cells produced 175 mg/L CLA from 500 mg/L LA for 1 h with a productivity of 175 mg/(L.h) and accumulated 5.5 times more CLA than that obtained from bioconversion by free washed cells. The CLA-producing ability of reused cells was investigated over five reuse reactions and was maximal at pH 7.5, 25 degrees C, and 1.0 mM Cu(2+). The total amount of CLA by the combined five reuse reactions was 344 mg of CLA/L reaction volume. This was 8.6 times higher than the amount obtained from reuse reactions by free washed cells.
authors.affiliation: Department of Bioscience and Biotechnology, Sejong University, Seoul 143-747, Korea.
authors.forename: Sun-Ok
authors.initials: SO
authors.lastname: Lee
authors.forename: Geun-Wha
authors.initials: GW
authors.lastname: Hong
authors.forename: Deok-Kun
authors.initials: DK
authors.lastname: Oh
mesh_terms: D019149:Bioreactors / Q000382:microbiology*; D001711:Biotransformation; D018929:Cell Culture Techniques / Q000379:methods*; D018914:Cells, Immobilized / Q000502:physiology; D003300:Copper / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007778:Lactobacillus / Q000145:classification / Q000254:growth & development* / Q000378:metabolism*; D019787:Linoleic Acid / Q000378:metabolism*; D044243:Linoleic Acids, Conjugated / Q000096:biosynthesis*; D013696:Temperature
chemical_list: D044243:Linoleic Acids, Conjugated; D003300:Copper; D019787:Linoleic Acid