Conjugated linoleic acid production from various substrates by probiotic Lactobacillus plantarum

Conjugated linoleic acid (CLA, a colloquial term referring to a collection of geometrical and positional isomers of linoleic acid) has attracted the attention of scientists due to its special properties. In this study, we used sunflower oil and castor oil as cost-effective substrates (in comparison with linoleic acid) for CLA production. A novel method using bacterial lipase in order to convert sunflower oil and castor oil to free fatty acids was investigated. In addition, the effect of some significant parameters on CLA production, such as substrate type and concentration, incubation time, and probiotic lipase on sunflower oil and castor oil were evaluated. Among the five studied probiotic strains, washed cells of Lactobacillus plantarum (ATCC 8014) produced the highest concentration of CLA isomers. Analysis of results revealed that produced CLA was a mixture of two bioactive isomers including cis-9, trans-11- CLA (0.38 mg · ml−1) and trans-10, cis-12-CLA (0.42 mg · ml−1) from 8 mg · ml−1 sunflower oil by bacterial lipase conversion to linoleic acid. Hence, the capacity of L. plantarum (ATCC 8014) to produce bioactive isomers of CLA from cost-effective substrates is of interest for development of probiotic supplements such as CLA and other health-food products.