Effects Of LA Induction And Alcohol Stress On The Transformation Rate Of CLA In Lactobacillus Plantarum P-8 And Its Mechanism

Conjugated linoleic acid(Conjugated linoleic acid,CLA)is a general term for a variety of octadecadienoic acids containing conjugated double bonds,and has a variety of physiological effects that benefit organisms.Studies have found that lactic acid bacteria can convert linoleic acid(LA)and generate CLA.In this conversion process,Fatty acid hydratase(CLA-HY),Hydroxy fatty acid dehydrogenase(CLA-DH),Acetoacetate decarboxylase(CLA-DC)are required to participate.There also are related Enone reductase(CLA-ER)and Enolase(Eno).In this experiment,the effect of LA induction and alcohol stress on the CLA conversion rate of L.plantarum p-8 Strain and its mechanism were completed,which laid a foundation for elucidating the molecular mechanism of CLA production by L.plantarum p-8 Strain and Looking for effective control measures to improve CLA generation.The experiment obtained the following results:The first,Lactobacillus plantarum p-8 has a low ability to transform LA into CLA.The generated CLA is mainly distributed in the fermentation broth,including c9,t11-CLA,t10,c12-CLA and t9,t11-CLA Isomer form.But there are very few t10,c12-CLA in the bacteria.According to the type of product,it can be judged that the CLA generation conforms to the approach proposed by Kishino.Second,in the range of 0.01 mg/mL?0.05mg/mL,as the LA concentration increases,the conversion rate of the three CLA isomers in the fermentation broth also increases.The five enzyme genes related to CLA synthesis,cla-hy,cla-dh,cla-dc,cla-er and cla-eno mRNA levels also increased.It indicated that the synthesis of CLA is positively correlated with the transcription level of CLA synthesis-related enzyme genes.Third,when adding 0.05mg/mL LA to the medium and using different concentrations of methanol and ethanol for stress,respectively,when the concentration is less than 0.5%,the conversion rate of the three isomers of CLA was increased with the increasing of concentration.The mRNA expressions of the five enzyme genes related to CLA synthesis also were increased,but the stress increased most at 0.5%concentration.It showed that alcohol stress within a certain concentration range could promote the conversion of CLA and the transcription level of enzyme genes related to CLA synthesis.