摘要

        发现一种新的细菌素一直是科学界的一件大事，因为大多数细菌的培养是微生物学中的一个普遍问题。这一说法反映在细菌素的数量比已知的抗菌肽小10倍。我们在简化培养基上培养屎肠球菌以减少纯化步骤的数量。此方法可用于纯化由屎肠球菌ICIS 7产生的新型重质细菌素。通过N-末端测序和结构功能特性与现有数据的比较，证实了这种细菌素的新颖性，即肠毒素-7。纯化的肠毒素-7在UniProt/SwissProt/TrEMBL数据库中的氨基酸残基序列没有同源性：NH2-Asp-Ala-His-Leu-Ser-Glu-Val-Ala-Glu-Arg-Phe-Glu-Asp-Leu-Gly。分离出的耐热蛋白分子量为65kDa，在细菌素分类方案中将其分为III类。肠霉素-7对革兰氏阳性和革兰氏阴性微生物具有广谱的抗菌活性。荧光显微镜和光谱仪显示了肠毒素-7的渗透机制，在几分钟内就实现了。

        Discovery of a novel bacteriocin is always an event in sciences, since cultivation of most bacterial species is a general problem in microbiology. This statement is reflected by the fact that number of bacteriocins is smaller for tenfold comparing to known antimicrobial peptides. We cultivated Enterococcus faecium on simplified medium to reduce amount of purification steps. This approach allows to purify the novel heavy weight bacteriocin produced by E. faecium ICIS 7. The novelty of this bacteriocin, named enterocin-7, was confirmed by N-terminal sequencing and by comparing the structural-functional properties with available data. Purified enterocin-7 is characterized by a sequence of amino acid residues having no homology in UniProt/SwissProt/TrEMBL databases: NH2 - Asp - Ala - His - Leu - Ser - Glu - Val - Ala - Glu - Arg - Phe - Glu - Asp - Leu - Gly. Isolated thermostable protein has a molecular mass of 65 kDa, which allows it to be classified into class III in bacteriocin classification schemes. Enterocin-7 displayed a broad spectrum of activity against some Gram-positive and Gram-negative microorganisms. Fluorescent microscopy and spectroscopy showed the permeabilizing mechanism of the action of enterocin-7, which is realized within a few minutes.

        https://link.springer.com/article/10.1007%2Fs12602-018-9392-0