Abstract: Multiple enzymes were involved for CLA production in lactic acid bacteria (LAB) . Myosin cross reactive antigen (MCRA) gene was amplified with the specific primer from Lactobacillus plantarum ZS2058 according to reported putative linoleate isomerease in LAB in NCBI. MCRA gene was cloned and expressed successfully into Escherichia coli, the recombinant MCRA was analyzed by SDS-PAGE and Western Blot, and the results indicated the molecular weight of MCRA was 67ku. After purification with affinity chromatography, the activity of recombinant MCRA was analyzed. The GC-MS results showed that MCRA catalyzed linoleic acid into 10-hydroxy-cis-12-octadecenoic acid, and catalyzed oleic acid into 10-hydroxy-octadecanoic acid.