Abstract:

In this work, the fermentation conditions for converting linoleic acid into conjugated linoleic acid (CLA) by Lactobacillus plantarum lp15-2-1 were studied. Single factor experiments were done to understand the effects of inoculum amount, incubation temperature, pH, incubation time and initial level of linoleic acid on CLA production. Using response surface Box-Benhnken design, a quadratic polynomial regression model was established. The results indicated that the optimal levels of incubation temperature, initial level of linoleic acid and pH were30 ℃, 0.21 mg/mL and 6.3, respectively. Under these optimal fermentation conditions, the yield and conversion rate of CLA were 44.77μg/mL and 21.32 %, which were higher than the predicted values of 45.326μg/mL and 7.78 %, respectively.

Key words: conjugated linoleic acid (CLA), Lactobacillus plantarum, response surface methodology