Co-expression of Nisin Z and Leucocin C as a Basis for Effective Protection Against Listeria monocytogenes in Pasteurized Milk.
Co-expression of Nisin Z and Leucocin C as a Basis for Effective Protection Against Listeria monocytogenes in Pasteurized Milk.
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Nisin Z 和 Leucocin C 的共表达是有效预防巴氏杀菌牛奶中单核细胞增生李斯特氏菌的基础
DOI：
10.3389/fmicb.2018.00547
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发表时间：
2018
影响因子：
5.2
通讯作者：
Qiao M
中科院分区：
文献类型：
--
作者：
Fu Y;Mu D;Qiao W;Zhu D;Wang X;Liu F;Xu H;Saris P;Kuipers OP;Qiao M
乳链菌肽是乳酸乳球菌（Lactococcus lactis subsp.）主要对各种革兰氏阳性菌有活性。Leucocin C是由Leuconostoc carnosum 4010产生的一种IIa类细菌素，用于抑制单核细胞增生李斯特菌的生长。由于两种细菌素具有不同的作用模式，因此它们的联合使用可能是有效抑制食源性病原体的潜在策略。在本研究中，L.以食品级载体L.乳酸菌N8。两种细菌素的生产稳定维持。抑菌实验表明，重组菌株对单核细胞增生李斯特菌和金黄色葡萄球菌有较强的抑菌活性，对肠道沙门氏菌和大肠杆菌有较强的抑菌活性，首次证明了nisin和leucocin C的共表达具有高效的抑菌活性。棋盘格法表明，L.乳酸菌N8-r-lecCl上清液在低浓度EDTA存在下增强。扫描电子显微镜图像分析显示L.的细胞形态变化最大。用EDTA和L.乳酸菌N8-r-lecCl上清液。通过时间杀菌试验验证了该方法在巴氏奶中的实际效果。洛杉矶同时表达乳链菌肽和白细胞菌素C的乳酸菌N8-r-lecCI菌株具有较强的抑菌活性，在巴氏杀菌乳加工和保鲜中具有良好的应用前景。
Nisin, an important bacteriocin from Lactococcus lactis subsp., is primarily active against various Gram-positive bacteria. Leucocin C, produced by Leuconostoc carnosum 4010, is a class IIa bacteriocin used to inhibit the growth of Listeria monocytogenes. Because two bacteriocins have different modes of action, the combined use of them could be a potential strategy for effective inhibition of foodborne pathogens. In this study, L. lactis N8-r-lecCI (N8 harboring lecCI gene) coexpressing nisin–leucocin C was constructed based on the food-grade carrier L. lactis N8. Production of both bacteriocins was stably maintained. Antimicrobial measurements showed that the recombinant strain is effectively against Listeria monocytogenes and Staphylococcus aureus and moderately against Salmonella enterica serovar Enteritidis and Escherichia coli because of its stronger antibacterial activity than the parental strain, this result first demonstrated that the co-expression of nisin and leucocin C results in highly efficient antimicrobial activity. The checkerboard assay showed that the antibacterial activity of L. lactis N8-r-lecCI supernatant was enhanced in the presence of low concentration of EDTA. Analysis of the scanning electron microscope image showed the biggest cellular morphology change in L. monocytogenes treated with a mixture of EDTA and L. lactis N8-r-lecCI supernatant. The practical effect was verified in pasteurized milk through time-kill assay. The L. lactis N8-r-lecCI strain expressing both nisin and leucocin C has a promising application prospect in pasteurized milk processing and preservation because of its strong antibacterial activity.