Linoleic acid isomerase activity in enzyme extracts from Lactobacillus acidophilus and Propionibacterium freudenreichii ssp. shermanii

Abstract

Enzyme extracts from Lactobacillus acidophilus (CCRC14079) and Propionibacteriurn freudenreichii ssp. shermanii (CCRC11076) were reacted with linoleic acid at 50°C for 10 min at pH 5, 6, 7, and 8, and the levels of conjugated linoleic acid (CLA) formation were determined by high performance liquid chromatography. CLA formations were observed in all the reactions catalyzed by the retentates using ultrafiltration membranes with 100 kDa nominal molecular weight cutoff, indicating the presence of the activity of linoleic acid isomerase with nominal molecular weight higher than 100 kDa in the retentates from two cultures. More CLA was formed at pH 5 of L. acidophilus treatment and t10c12, c11t13, and c9t11 CLA were 3 major CLA isomers produced. Results demonstrate a potential for CLA production through linoleic acid isomerase.