Production of Conjugated Linoleic Acid by Transformed E.coli

Background and

Due to the beneficial physiological effects of conjugated linoleic acid (ÇLÂ), there has been a growing tendency to produce it as a functional lipid in recent years. Different ÇLÂ isomers have different physiological effects; hence, production of certain ÇLÂ isomers with high purity is of great importance. ÇLÂ can be produced through both chemical and enzymatic methods; however, unlike chemical catalysts, enzymes make it possible to produce pure ÇLÂ isomers. Ïn this study, linoleic acid isomerase from Propionibacterium acnes was expressed in Ë. coli and the possibility of the production of ÇLÂ was studied.

The vector containing linoleic acid isomerase, pGËX-6P-PÂÏ, was transformed in Ë. coli. Transformants were selected based on their resistance to ampicillin and restriction digestion analysis. To express the recombinant linoleic acid isomerase, transformants were induced using isopropyl-beta-thiogalactopyranoside (ÏPTG). The expression of recombinant protein was confirmed by SDS-polyacrylamide gel electrophoresis and Western blotting using anti-linoleic acid isomerase antibody. Then, the possibility of the production of ÇLÂ from Linoleic acid by using Ë-coli transformant was investigated.

Recombinant linoleic acid isomerase was intracellularly produced as a glutathione S-transferase (GST) tagged protein by transformed Ë-coli. The fusion of GST to the N-terminus of linoleic acid isomerase increased its molecular weight from 49 to 75 kDa. GST-tagged enzyme acted like linoleic acid isomerase and the transformed bacterium could convert considerable amounts of linoleic acid to ÇLÂ.Çonclusion: The findings indicated that transformed Ë. coli can be used for ÇLÂ production in biocatalytic processes.