猪消化道中产苯乳酸乳酸菌的益生特性研究

【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。

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

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.