Presence of additional peptidases in Streptococcus thermophilus CNRZ 302 compared to Lactococcus lactis
Presence of additional peptidases in Streptococcus thermophilus CNRZ 302 compared to Lactococcus lactis
复制标题
与乳酸乳球菌相比，嗜热链球菌 CNRZ 302 中存在额外的肽酶
DOI：
10.1046/j.1365-2672.1997.00185.x
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发表时间：
1997
影响因子：
4
通讯作者：
V. Monnet
中科院分区：
文献类型：
--
作者：
F. Rul;V. Monnet
嗜热链球菌在乳品工业中应用广泛，但对其肽酶系统知之甚少。本研究的目的是确定该系统的生化和遗传特性，并将其与著名的乳酸乳球菌系统进行比较。我们对Strep的胞内蛋白进行了分离。对嗜热菌CNRZ 302和乳酸乳杆菌NCDO 763进行了离子交换层析，并对不同类型的多肽酶进行了活性测定。在乳链霉菌和链霉菌中均有表达。结果表明，嗜热菌和嗜热菌具有13种不同的多肽酶活性，且两种菌株的生化同源性较高。嗜热链球菌还含有乳酸乳杆菌 中没有的两种肽酶：一种氨基肽酶和一种寡肽酶。我们进行了Southern杂交实验，在所测试的8个肽酶基因中，只有编码一般氨基肽酶的基因PepC和PepN在乳酸乳杆菌和链霉菌之间是同源的。嗜热菌菌株。除了生化和遗传上的相似性外，链霉菌的肽酶系统也是如此。因此，嗜热菌和乳酸乳杆菌的不同之处在于链霉菌中存在额外的多肽酶。嗜热菌。
Streptococcus thermophilus is widely used in the dairy industry but little is known about its peptidase system. The aim of this study was to determine the biochemical and genetic characteristics of this system, and to compare it to the well known system of Lactococcus lactis. We separated the intracellular proteins of Strep. thermophilus CNRZ 302 and L. lactis NCDO 763 by ion‐exchange chromatography and we detected the activity of the different types of peptidases. In both L. lactis and Strep. thermophilus strains, we showed 13 different peptidase activities with biochemical homologies between both species. Streptococcus thermophilus also possessed two peptidases which we did not find in L. lactis : an aminopeptidase and an oligopeptidase. We performed Southern blot experiments and among the eight peptidase genes tested, only the genes encoding the general aminopeptidases, pepC and pepN, were homologous between the L. lactis and Strep. thermophilus strains. Besides biochemical and genetic similarities, the peptidase systems of Strep. thermophilus and L. lactis thus differed by the presence of additional peptidases in Strep. thermophilus.