Study On The Production Of Conjugated Linoleic Acid By Lactobacillus Plantarum Lp15-2-1

Conjugated linoleic acid(short for CLA) is a set of octadecadienoic acid with conjugated double bounds, and they're isomers to essential fatty acids linoleic acid(short for LA). It's reported that CLA has a function of anti-oxidant, anti-cancer, anti-atherosclerosis and reduce body fat and so on. In this paper, we researched the ability of transforming LA into CLA by Lactobacillus plantarum lp15-2-1, and discussed LA isomerase's enzymatic properties, to provide experimental basis for subsequent in-depth study and large-scale industrial production.The condition of converting LA into CLA was studied by using Lactobacillus plantarum lp15-2-1. On the basis of single factor experiments, designed a quadratic polynomial regression model by using Box-Benhnken trial design. Results showed that the optimal parameters was:incubation temperature 30℃, the initial level of LA 0.21 mg/mL, pH 6.3, the actual yield of CLA is 44.77μg/mL, the conversion rate is 21.32%, compare to 7.78% at the beginning.The condition of converting LA to CLA was studied by washed cells from Lactobacillus plantarum lp15-2-1. On the basis of single factors, central composite design was used to make a quadratic polynomial regression model. And the results showed that the optimal parameters was:incubation temperature 31℃, the initial level of LA 3.8mg/mL, pH 5.7, culture time 84h and the cell concentration 32%, the actual yield of CLA is 354.58μg/mL.Different cell disruption methods on Lactobacillus plantarum lpl 5-2-1 producing CLA was researched, discussed LA isomerase's enzymatic properties, and the best conditions was that 30℃, pH5.5. Plus, it's more active in slightly acidic environment. The localization of LAI was studied by differential certrifugation which showed that LAI was a membrane-bound enzyme, while adding detergent Triton X-100 didn't show significant results.