Abstract:

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.

Key words: conjugated linoleic acid, linoleic acid isomerase, Lactobacillus delbrueckii subsp bulgaricus