保加利亚乳杆菌诱导产亚油酸异构酶条件研究

亚油酸异构酶可由保加利亚乳杆菌经诱导产生，可以将亚油酸(LA)转化为共轭亚油酸(CLA)。本实验对诱导保加利亚乳杆菌产亚油酸异构酶的条件进行研究，利用紫外和气质联用仪(GC-MS)检测所生成的CLA。结果表明：在培养基中添加1.5‰(V/V) LA 时所产酶的共轭亚油酸转化率最高；温度为36℃，培养36h 为较适的培养条件；单独添加0.1%(m/V)的乳糖或0.1%(m/V)的氯化钠有利于诱导产酶；在培养基中直接添加LA 的效果优于培养3至12h 后再进行添加。诱导所产酶可将LA 转化为CLA，且含有9c,11t-CLA 异构体。

Production of Linoleic Acid Isomerase from Lactobacillus delbrueckii subsp bulgaricus

Linoleic acid isomerase capable of converting linoleic acid (LA) to conjugatede linoleic acid (CLA), was produced by Lactobacillus delbrueckii subsp bulgaricus. The production condition for linoleic acid isomerase with Lactobacillus delbrueckii subsp bulgaricus were investigated through UV and GC-MS. The result showed that the highest yield was obtained when 1.5‰ of LA (V/V) was added to the medium. The Optimum condition for Lactobacillus delbrueckii subsp bulgaricus culture was shown as follows: temperature was 36 ℃and time was 36 h. Addition of 0.1% (m/V)of Lactose or 0.1%(m/V) of NaCl alone to medium was favorable for linoleic acid isomerase to produce CLA. The direct addition of LA to medium led to higher production efficiency than addition after 3-12 h of culturation. GC-MS data suggested that linoleic acid isomerase was able to convert LA to CLA,which contained cis-9, trans-11 isomer.