奶中两种共轭亚油酸异构体的特异性合成机制的体外研究

项目名称： 奶中两种共轭亚油酸异构体的特异性合成机制的体外研究

项目编号： No.31260373

项目类型： 地区科学基金项目

立项/批准年度： 2013

项目学科： 农业科学

项目作者： 刘晓华

作者单位： 南昌大学

项目金额： 48万元

中文摘要： 共轭亚油酸（CLA）具有多种重要的生理活性，其中c9,t11-CLA具有很强的抗癌作用，t10,c12-CLA具有减肥和防治2型糖尿病的功能。在自然界，CLA主要存在于牛羊的奶中，通常包含c9,t11-CLA和t10,c12-CLA等异构体，牛羊瘤胃中的一些细菌参与了不同CLA异构体的生物合成。本项目拟通过UV扫描、毛细管电泳等方法从山羊瘤胃细菌中筛选分离出能合成c9,t11-CLA和t10,c12-CLA的菌株，通过生化特性和基因学分析，了解这些菌株的属种和同源性关系。再通过PCR-RFLP技术，分析菌株中亚油酸异构酶基的多态性，从亚油酸异构酶的基因水平阐明奶中c9,t11-CLA和t10,c12-CLA的特异性合成机理。最后研究CLA合成菌株在人工模拟瘤胃环境中的生长代谢，通过PCR-DGGE技术，从瘤胃微生态的群体水平进一步阐明c9,t11-CLA和t10,c12-CLA的代谢机理。

中文关键词： 奶；共轭亚油酸；异构体；合成；瘤胃细菌

英文摘要： Conjugated linoleic acid (CLA) is a collective term for geometric and positional isomers of linoleic acid with conjugated double bonds. They have been found to be responsible for many biological properities that related to human health. c9,t11-CLA has the anticarcinogenic activity, and t10,c12-CLA seems to be specifically responsible for reducing body fat and enhancement of energy metabolism. CLA occurs naturally in the fat of milk in a relatively low level. There are several CLA isomers in milk, such as c9,t11-CLA and t10,c12-CLA. These CLA isomers are mainly biosynthesized by some bacteria in the rumen of cow and goat. Ultraviolet spectral scan and capillary electrophoresis methods will be used to screen and identify bacteria which can biosynthesize c9,t11-CLA and t10,c12-CLA, respectively, from goat's rumen bacteria. The isolated bacteria will be identified to species by classical methods and 16S rRNA analysis. The gene of linoleic acid isomerase, which converts linoleic acid to CLA, will be amplified by polymerase chain reaction (PCR) and analyzed the gene polymorphism by restriction fragment length polymorphism (RFLP). The reason of isomer specific biosynthesis can be clarified with the find of the gene polymorphism of linoleic acid isomerase. The fermentation and metabolism of these CLA biosynthesis bacte

英文关键词： milk；conjugated linoleic acid；isomer；biosynthesis；rumen bacteria