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In recent years , conjugated linoleic acid ( CLA ) have attracted much attention as a novel with a wide range of biological activity of fatty acid , anti-tumor , anti- atherosclerosis atherosclerosis , strengthen the immune system and promote good growth and other effects , is widely used medicine, food additives and health products industry . Industrial chemical production of CLA is difficult to meet the high purity of medicines, food and feed area , no harmful ingredients residual requirements . The paper filter CLA produced lactic acid bacteria from food and to increase its production CLA for the purpose of the CLA method for the determination , and the filter the strains medium and fermentation conditions were optimized , the main contents and results are as follows : from sauerkraut juice , raw milk and yogurt filter out the certain production CLA suspected strains , establish CLA UV detection methods , production CLA detected more strain 3 from sauerkraut juice (LJ-05, LJ-12, LJ- 41 ) , one from raw milk ( LJ - 43 ) , 1 strains from yogurt ( LJ - 53 ) , the highest level of strain LJ - 05 's production CLA . Strain LJ - 05 The product by gas chromatography analysis of the fatty acid product produced 9c , 11t - CLA and 10t , 12c -CLA , the relative content of respectively 0.81% and 1.79 % , 9c , 11t - CLA and 10t , 12c - CLA , respectively, accounting for 31.15% and 68.85% of the CLA . Using traditional physiological and biochemical methods for preliminary identification of the strain LJ - 05 , and then through the Biolog Microbial Identification System to the identification of the species , a comparative analysis of the identification results , the final identification of strains LJ - 05 Lactobacillus ( Lactobacillus planetarium ). 3 orthogonal experiment and response surface methodology study of plant Lactobacillus LJ - 05 fermentation medium formulation of the optimization of the production of CLA and generate the CLA the best fermentation conditions were . The optimal medium composition : 4% glucose , 1% peptone , beef extract, 1% , 1% yeast extract , 0.2% of diammonium hydrogen citrate , sodium acetate, 0.5% , 0.2% dipotassium hydrogen phosphate , magnesium sulfate, 0.04 % manganese sulfate 0.025% ; optimum fermentation conditions were : standing limit oxygen culture conditions , LA emulsion added amount of 0.23 %, 3.95% of the inoculum size , initial pH value was 7.3 , temperature 36 ° C , cultured for 36 hours . Lactobacillus plantarum LJ - 05 of CLA production from before optimization 365.1μg / ( mL fermentation broth ) to 510.9μg / ( mL fermentation broth ) , production increased by 39.93% , a more substantial increase .
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