食品科学 ›› 2018, Vol. 39 ›› Issue (14): 199-205.doi: 10.7506/spkx1002-6630-201814030

• 生物工程 • 上一篇    下一篇

西部传统发酵乳品中乳酸菌筛分及其亚硝酸盐降解能力

张兴吉1,葛武鹏1,*,刘阳1,王瑞1,王智2,李小鹏3   

  1. (1.西北农林科技大学食品科学与工程学院,陕西?杨凌 712100;2.陕西百跃优利士乳业有限公司,陕西?西安 710000;3.咸阳市食品药品检测检验中心,陕西?咸阳 712000)
  • 出版日期:2018-07-25 发布日期:2018-07-16
  • 基金资助:
    陕西省科技厅战略性新兴产业重大产品(群)项目(2015KTCQ03-08;2016KTZDNY02-04)

Isolation and Identification of Lactic Acid Bacteria from Traditional Fermented Milk in Western China and Their Nitrite Degradation Capability

ZHANG Xingji1, GE Wupeng1,*, LIU Yang1, WANG Rui1, WANG Zhi2, LI Xiaopeng3   

  1. (1. College of Food Science and Engineering, Northwest A&F University, Yangling 712100, China; 2. Shaanxi Baiyue Youlishi Dairy Co. Ltd., Xi’an 710000, China; 3. Xianyang Food and Drug Inspection Center, Xianyang 712000, China)
  • Online:2018-07-25 Published:2018-07-16

摘要: 为探究西部牧区传统发酵乳品中乳酸菌多样性及其优势菌种的亚硝酸盐降解能力,为工业化利用提供参考,应用16S rDNA技术鉴定分离菌株,并对分离菌株亚硝酸盐降解能力采用比色法进行分析,比较不同地区、不同发酵乳品中不同种类乳酸菌亚硝酸盐降解能力的差异。结果表明:1)104?份样品中共分离得到275?株乳酸菌,鉴定出6?个属23?个种,其中瑞士乳杆菌(Lactobacillus helveticus)为青海、甘肃、新疆、内蒙古、西藏传统发酵乳品中共有菌株,L. helveticus和植物乳杆菌(L. plantarum)为酸牦牛奶、酸马奶、酸驼奶、奶渣发酵乳品中共有菌株。2)275?株乳酸菌亚硝酸盐降解率在4.8%~99.9%之间波动,其中50%的菌株表现出较好的亚硝酸盐降解能力,平均在91.3%以上。3)降解能力因菌株来源和乳酸菌种类不同存在差异性,来源于西藏的菌株显著高于青海、甘肃、新疆的菌株(P<0.05);来源于奶渣中的菌株显著高于酸牦牛奶和酸马奶中的菌株(P<0.05);在分离出的8?种优势菌株中L. plantarum、副干酪乳杆菌(L. paracasei)、短乳杆菌(L. breris)显示了稳定高效的亚硝酸盐降解能力,其中L. plantarum降解能力最强,且部分菌种间降解能力存在显著性差异(P<0.05)。

关键词: 乳酸菌, 分离鉴定, 亚硝酸盐, 降解率

Abstract: The aims of this study were to explore the diversity of lactic acid bacteria (LAB) in traditional fermented milk in western China and to analyze the nitrite degradation capability of the dominant strains in order to provide useful data for their industrial application. The LAB isolates, isolated from different fermented milk products from different pastoral areas, were identified by 16S rDNA sequence analysis, and their nitrite degradation capabilities were comparatively determined by colorimetry. The results obtained showed that: 1) A total of 275 LAB strains were isolated from 104 fermented milk samples, belonging to 23 species in 6 genera. Lactobacillus helveticus was detected from the samples from Qinghai, Gansu, Xinjiang, Inner Mongolia and Tibet. Meanwhile, L. helveticus and L. plantarum were isolated from fermented yak milk, koumiss, shubat and milk dreg. 2) The nitrite degradation rates?of 275 LAB isolates were between 4.8% and 99.9%, 50% of which had good nitrite degradation capability with an average of over 91.3%. 3) The nitrite degradation capability of these LAB isolates varied depending on the sources and species. The effect of LAB from Tibetan was significantly higher than that of LAB from Qinghai, Gansu and Xinjiang (P < 0.05), and the effect of LAB from milk dreg was significantly higher than that of LAB from fermented yak milk and koumiss (P < 0.05). L. plantarum, L. paracasei and L. breris could stably and efficiently degrade nitrite, and L. plantarum had the strongest nitrite degradation ability among the 8 dominant strains. However, a significant difference in the nitrite degradation ability was found among some dominant strains (P < 0.05).

Key words: lactic acid bacteria, isolation and identi?cation, nitrite, degradation rate

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