Breeding Of Producting Conjugated Linoleic Acid Lactobacillus And Study Of The Fermentation Conditions By N~+ Implanting

Conjugated linoleic acid(CLA),because of its unique physiological function,in the last 20 years,it has been concerned particularly.Large number of studies have confirmed that CLA has anti-cancer,anti-artery atherosclerosis,reducing cholesterol,promoting growth,inhibiting fat accumulation function.At present,the extensive use of chemical method will obtain the product of the series with a variety of geometric isomers of CLA mixture,but biological fermentation will produce a single isomer,the mild reaction conditions,has been gradually arouse people's attention.Therefore,studying how to improve producting CLA bacteria performance,improve fermentation process has a very important significance.In the study,Lactobacillus plantarum is regarded as the starting strains,using low-energy ion beam nitrogen Mutation Breeding screening method to get a more stable production CLA high-yielding strains ANLP.ANLP strain and its growth characteristics were studied,at the same time the conditions of synthesis CLA were optimized.Test 1:Studying its survival rate and mutation rate by N+injection of different doses and energy to starting strains of Lactobacillus plantarum.the result show that:when N⁺ energy is certain(10 Kev),the dose of 20 to 120×2.6×10¹³ ions/cm².First,Lactic acid bacteria survival rate show descend rapidly,when injected dose increased to 40×2.6×10¹³ ions/cm² survival rate has gentle recovery,injected dose is 80×2.6×10¹³ ions/cm²,survival rate rose to 31.86%,and then begin to decline again,whole survival is a typical "saddle-shaped" curve.When the microbial mutagenesis survival rate at 25%to 30%,the positive traits goals are often higher mutation rate,in 10 Kev,injected dose election 80×2.6×10¹³ ions/cm² for the best injected dose.In addition,in certain dose injection of N⁺ (80×2.6×10¹³ ions/cm²),the energy of 5～25 when Kev strain mutation rate is increased with the energy,there was a slow rising trend because of the mutation rate is too high,the survival rate optional low strain much higher survival rate,the mutation rate is low.In 10 Kev,the survival rate was 34%,the direct mutation rate was 25%.Considered in the injected dose of 80×2.6×10¹³ ions/cm²),10 Kev is the best election into energy.The N⁺ implanted repeatedly mutagenesis,high-yielding mutant strains ANLP acid production capacity from the strain of 33.44μg/mL increased to 103.26μg/mL,respectively.5 mutant strain by the culture,the stability of acid production.Test 2:Studying the changing of yield CLA and mutant strain some biological characteristics after N+injected into the Lactobacillus plantarum,testing results show that: Compared with the original strain,changes in cell growth cycle,shortening the growing number of 4 h,stability,and long-term colonies become larger,thicker cell variable length; cell production Acidic enhanced.Test 3:The different CLA fermentation conditions were studied.First,a single-factor test,research fermentation process different inoculum,linoleic acid content,temperature, incubation time,factors such as the initial pH in the fermentation broth CLA yield.Then, five factors affecting this orthogonal experiment with a view to gaining the best combination.The results showed that:inoculation of 2%,0.12%linoleic acid content, temperature 36℃,pH value of 6.5,36h culture time when the optimum conditions for the best,under optimum conditions,ANLP acid production amounted to 115.22μg/mL,it is higher than the original strain of about 3.5 times.At the same time,linoleic acid induction training,as well as training oscillation Tween-80 CLA emulsion dispersion of the output is raised.