摘 要:【目的】研究纳豆脂肽对牛奶的保鲜效果。【方法】采用微生物发酵法从纳豆菌中提取出纳豆脂肽，采用平板计数法(GB4789.2-1994)测定菌落总数并通过对金黄色葡萄球菌生长状况来探讨纳豆菌脂肽对牛乳的保鲜效果。【结果】在常温条件下，纳豆脂肽可以抑制牛奶中金黄色葡萄球菌的生长，且最有效的抑制浓度是0.1~0.3mg/ml，与添加1%的苯甲酸钠的抑制效果相当。在37℃条件下，纳豆脂肽也可以抑制牛奶中金黄色葡萄球菌的生长，且最有效的浓度是0.03~0.1mg/ml，与添加1%的苯甲酸钠的抑制效果相当。【结论】添加纳豆脂肽可有效提高巴氏杀菌奶的保鲜效果，所以可作为一种天然防腐剂广泛推广。

关键词：纳豆脂肽  牛奶  保鲜  苯甲酸钠  金黄色葡萄球菌

Abstract:[Objective]The fresh-keeping effect of natto lipeptide on milk.[Methods]Extraction natto lipopeptide from bacollus natto by microbial fermentation,using the enumeration by platecount method (GB4789.2-1994) to determine of the total number of colonies and through observe the growth curve of Staphylococcus aureus to explore the fresh-keeping effect of bacillus natto peptide in milk.[Results]Under the condition of normal temperature, natto lipidpeptide can inhibit the growth of Staphylococcus aureus in milk, concentration and most inhibit effective is 0.1~0.3mg/ml, the effect of inhibition is similar to sodium benzoate added 1%. In the condition of 37℃, natto lipopeptide can also inhibit the growth of Staphylococcus aureus in milk, concentration and most inhibit effective is 0.03~0.1mg/ml, the effect of inhibition is also similar to sodium benzoate added 1%.[Conclusion] natto lipopeptide could effectively improve the fresh-keeping effect of pasteurized milk, so it can be widely used as a natural preservative.

Key Words：Bacillus natto lipopeptide  Milk Fresh-keeping Sodium benzoate    Staphylococcus aureus