Factors affecting conjugated linoleic acid production by Lactobacillus plantarum GSI 303

Conjugated linoleic acids (CLAs), an isomerization product of linoleic acid (LA), have been found to provide beneficial physiological effects for health. Lactobacillus plantarum GSI 303, a strain, selected for its potential in CLAs synthesis, was studied to understand the conditions that may enhance CLA production. The maximum concentration of CLA was 6.0 mg/g fat obtained from the optimum conditions for culturing in de Mann Rogosa Sharp (MRS) broth and skim milk media contain 2 mg/mL LA, initial pH 6.5, and incubation at 37°C for 24 h. By performing either in aerobic or anaerobic conditions, CLA production was not significantly different and prolonging incubation time from 24 to 48 h did not enhance CLA formation (p>0.05). Incubation at 37°C, CLA content was higher than at 43°C and 15°C. In addition, L. plantarum GSI 303 produced CLA in skim milk media higher than did L. reuteri ATCC 55739 which was used as a positive bacterial control for CLA production.