猪消化道中产苯乳酸乳酸菌的益生特性研究

Probiotic characteristics of phenyllactic acid-producing LAB from swine's digestive tract

摘要:

【目的】建立一种简单有效的产苯乳酸乳酸菌的筛选方法，并筛选到高产苯乳酸的乳酸菌。【方法】菌株经过添加了苯丙氨酸的培养基厌氧培养后，利用高效液相色谱法检测发酵液中苯乳酸的含量。【结果】从猪的消化道中共分离得到31株产苯乳酸的乳酸菌, 其中菌株R53的苯乳酸产量最大, 为321.7 mg/L。菌株R53对·OH、O2?和DPPH都有清除能力, 清除率分别达到11.2%、52.7%和63.2%。同时R53也能降低培养基中胆固醇的含量, 清除率为32.5%。【结论】乳酸菌R53经菌落形态、细胞形态、生化反应实验、16S rDNA 测序, 最终确定为植物乳杆菌。植物乳杆菌R53能产生苯乳酸，具有清除胆固醇和抗氧化能力。

Abstract:

[Objective] A simple and efficient method for screening lactic acid bacteria which would produce phenyllactic acid (PLA) would be developed. [Methods] Strain R53 was incubated in MRS ( de Man , Rogosa , Sharpe ) broth supplemented with phenylalanine by the anaerobic culture, and PLA in the fermentation broth was determined by HPLC. [Results] 31 strains were obtained from swine's digestive tract, of which strain R53 from duodenum showed the highest PLA-producing ability (321.7 mg/L). Strain R53 showed the ability to inhibit the on the three radicals. The results showed that the radical-scavenging ratios on ·OH, O2ˉ ,and DPPH were 11.2%, 52.7% and 63.2% respectively. In addition, strain R53 could degrade cholesterol and the degradation rate was 32.5% in vitro. [Conclusion] Strain R53 was identified as Lactobacillus plantarum through its culture characteristics, morphological observation, biochemistry experiment and combining with the phylogenetic analysis of 16S rDNA. L.?plantarum R53 had the ability of phenyllactic acid-producing, cholesterol-reducing, and free radical-scavenging.