产共轭亚油酸植物乳酸杆菌的筛选及鉴定

Screening and Identification of Conjugated Linoleic Acid-producing Lactobacillus planetarium Strains

本实验采用紫外分光光度法测定培养发酵液中CLA含量,经比较分析,从自然发酵酸菜汁中筛选出产CLA水平高的菌种;通过测定分析产CLA菌株的菌落和形态特征、产乳酸特性及生化生理特性,鉴定其种类。从自然发酵酸菜液中共筛选出18株产CLA菌株,当接种量为2%(V/V)时,其产CLA水平处于0.0954～0.6213mg/10ml发酵液之间。菌株X11产CLA的水平最高,达0.6213mg/10ml发酵液,亚油酸转化率为2.75%,并具有植物乳酸杆菌(Lactobacillus planetarium)的菌落和菌体形态特征、生化和生理特性,鉴定其为植物乳酸杆菌(Lactobacillus planetarium)。

The aim of this study was to screen Lactobacillus planetarium strains which can produce conjugated linoleic acid （CLA） from naturally fermented Chinese sauerkraut juice by determining the CLA content of fermentation liquild with spectrophotometry, and identify the strain with the highest CLA-producing capacity by determining and analyzing its lactic acidproducing capacity; cell and colony morphology, and biochemistry and physiological characteristics. Eighteen CLA-producing bacterium strains were isolated with the yield varying from 0.094 mg per10 ml medium to 0.6213 mg per10 ml medium. One of the CLA-producing strains, X11, has the highest capacity to produce CLA. X11, and by being cultured in 10ml culture solution with 251al linoleic acid for 24 h at 30 ℃, can produce 0.6213 mg CLA per 10 ml medium. The yield of X11 converting linoleic acid into CLA is 2.75%. Its configuration, lactic acid-producing, and biochemical and physiological characteristics lead to the identification of X11 as LactobaciUus plantarium.