传统发酵牦牛酸乳中高产胞外多糖乳酸菌的筛选与鉴定

陈孝勇; 赵欣; 骞宇; 李键; 陈炼红; 陈娟; 索化夷

doi:10.13386/j.issn1002-0306.2016.07.020

传统发酵牦牛酸乳中高产胞外多糖乳酸菌的筛选与鉴定

Screening and identification of lactic acid bacteria strains with high exopolysaccharide- producing from traditional fermented Yak Yogurt

摘要

摘要: 目的:以四川红原、西藏羊八井地区传统牦牛酸乳中分离出的57株乳酸菌作为实验菌种,筛选出高产胞外多糖乳酸菌。方法:通过菌落拉丝法、硫酸-苯酚法的测定。结果:实验菌株胞外多糖产量在19.95⁹1.08μg/m L之间,其中菌株代号为32-2、67-1、41-1和27的胞外多糖产量较高,分别为91.08、89.76、87.22、87.40μg/m L。通过16S r DNA序列同源性鉴定表明代号32-2菌株鉴定为屎肠球菌（Enterococcus faecium）、代号67-1菌株为肠膜明串株菌肠膜亚种（Leuconostoc mesenteroides subsp.mesenteroides）、代号41-1菌株为干酪乳杆菌（Lactobacillus casei）、代号27菌株为肠膜明串珠菌（Leuconostoc mesenteroides）。结论:为研究具有提高酸乳品质能力的发酵菌株提供依据。

Abstract: Objective: Screening lactic acid bacteria( LAB) with high exopolysaccharides from 57 strains of lactic acid bacteria,which were isolated and purified from traditional fermented Yak Yogurt in Hongyuan- Sichuan and Yangbajing- Tibet. Methods: The strains with high exopolysaccharides( EPS) were screened by colony thread-drawing method and phenol- sulfuric acid method. Results: The four strains,screening number 32- 2,67- 1,41- 1and 27,possessed the high exopolysaccharide- producing and the production was 91.08,89.76,87.22,87.40 μg / m L respectively.Based on 16 S r DNA sequence analysis,32- 2 was identified as Enterococcus faecium,41- 1 as Lactobacillus casei,67-1 as Leuconostoc mesenteroides subsp.mesenteroides,27 as Leuconostoc mesenteroides.Conclutions: This study could provide the evidence for researching fermentation strains to improve yogurt quality.