| 摘要: |
| 利用乳链菌肽抗性菌株中乳链菌肽抗性和乳糖发酵紧密连锁的原因，在含有乳链菌肽、乳糖和溴甲酚紫的选择培养基上，从205个新鲜的牛奶样品中定向筛选乳链菌肽抗性菌株。对筛选到的4株菌分析鉴定结果表明：4株菌均为革兰氏阳性菌，产乳酸，过氧化氢酶试验阴性；通过质粒的抽提和电泳，发现Lactococcus Lactis subsp.lactis ZL2009,ZL2009,ZL2010,ZL2024,ZL2030分别含有1，7，5，3条质粒带，且4株菌的质粒DAN分子大小不完全相同。 |
| 关键词: 菌株 乳酸乳球菌 乳链菌肽抗性 定向筛选 鉴定 乳链菌肽 食品添加剂 |
| DOI： |
| 修订日期：2001-07-24 |
| 基金项目:国家自然科学基金资助项目(30070571) |
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| Directional Screening and Identification of Nisin-resistant Lactococcus lactis |
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| Abstract: |
| According to the genetic loci of nisin-resistant (Nisr) linking to lactose-fermenting ability (Lac+) closely, four nisin-resistant Lactococcus lactis strains were directionally screened from 205 samples of fresh milk on a selective medium (M17) supplemented with nisin, lactose and bromocresol purple. The analysis of four strains demonstrated that they are Gram positive bacteria. The extraction of plasmid DNA illustrated that Lactococcus lactis subsp. lactis ZL2009, ZL2010, ZL2024, ZL2030 individually harboured 1,7,5 and 3 plasmids and they have different molecular weight. |
| Key words: Lactococcus lactis,nisin-resistant,directional screening,identification |
