为研究微生物源溶菌酶对14种供试菌的体外抑菌活性及对脂多糖(lipopolysaccharide,LPS)诱导的小鼠巨噬细胞RAW264.7细胞炎症的抑制作用,该文采用二倍稀释法测定微生物源溶菌酶对供试菌的最小抑菌浓度(mini-mum inhibitory concentration,MIC),评价其体外抑菌活性,通过构建LPS诱导的小鼠巨噬细胞RAW264.7炎症模型,以细胞中一氧化氮(nitric oxide,NO)及肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)的分泌量为指标,评价微生物源溶菌酶的抗炎活性.结果表明,微生物源溶菌酶对大肠杆菌、枯草芽孢杆菌、金黄色葡萄球菌、沙门氏菌、单增李斯特菌、耐热芽孢杆菌、酿酒酵母、酪丁酸梭菌、产黄青霉、黑曲霉和根霉11种菌均表现出良好的抑菌效果,具有较强的广谱抑菌性;在试验浓度范围内,对保加利亚乳杆菌、嗜热链球菌、乳酸乳球菌乳亚种3种益生菌无抑制效果,反而具有生长促进效果.微生物源溶菌酶对LPS诱导的小鼠巨噬细胞RAW264.7炎症模型表现出明显的抗炎作用,可显著降低NO及TNF-α的分泌,且与微生物源溶菌酶的作用浓度呈正相关.在试验浓度范围内,与模型组相比NO分泌量最高可降低57.92%,TNF-α分泌量最高可降低36.75%.微生物源溶菌酶具有良好的抑菌和抗炎活性,为其作为食品添加剂在抑制腐败菌生长、促进益生菌增殖等方面应用提供了理论基础.
The in vitro inhibitory activities of microbial lysozyme against 14 microbial species and lipopolysac-charide(LPS)-induced inflammation in RAW264.7 macrophages were determined.The minimum inhibitory concentration(MIC)of the microbial lysozyme against the microbial species were determined by double dilu-tion method,on the basis of which the in vitro antimicrobial activity of the lysozyme was measured.RAW264.7 macrophages were used to establish he LPS-induced inflammation model,and the anti-inflammatory activity of microbial lysozyme was evaluated based on the secretion of nitric oxide(NO)and tumor necrosis factor-alpha(TNF-a)in cells.The results showed that the microbial lysozyme exerted inhibitory effects against Escherichia coli,Bacillus subtilis,Staphylococcus aureus,Salmonella sp.,Listeria monocytogenes,Bacillus thermophilus,Sac-charomyces cerevisiae,Clostridium butyricum,Penicillium flavum,Aspergillus niger,and Rhizopu sp.,demon-strating strong broad-spectrum antimicrobial activities.Within the tested concentration range,the microbial ly-sozyme had no inhibitory effect against Lactobacillus bulgaricus,Streptococcus thermophilus or Lactococcus lac-tis lactis,but promoted their growth.The microbial lysozyme showed significant inhibitory effect on LPS-induced inflammation of RAW264.7 macrophages,which significantly reduced the secretion of NO and TNF-α in a concentration-dependent manner.Compared with the model group,the microbial lysozyme reduced the se-cretion of NO and TNF-α by 57.92%and 36.75%,respectively.Microbial lysozyme has good antimicrobial and anti-inflammatory activities,which provides a theoretical basis for its application as a food additive in inhibit-ing the growth of spoilage microorganisms and promoting the proliferation of probiotics.