Production, purification and characterization of a CLA-forming enzyme from Lactobacillus acidophilus.

摘要

Conjugated linoleic acid (CLA) has gained much attention recently due to its beneficial health and biological effects on animals and humans. However, the CLA-forming enzyme system has not been studied in details. Six strains of Lactobacillus acidophilus L11, L12, L14, L15, Lactobacillus fermentum and Lactobacillus reuteri were used to study the growth conditions and the production of CLA-forming enzyme in MRS media containing linoleic acid concentrations at 37°C. The purification and characterization of a CLA-forming enzyme were reported for the first time. The results showed that this enzyme has a molecular mass of 72 kDa, and is composed of two subunits. The optimal pH and temperature were 7.0 and 37°C, respectively. Kinetic study indicated that the enzyme has a high affinity for linoleic acid having a Km value of 1.49 x 10 -5 M and the Vmax was 17.1 muM/mg/min. The enzyme activity was inhibited by the metal chelators. (Abstract shortened by UMI.)