抗菌肽cp1对蜡样芽孢杆菌的抑菌作用及在巴氏杀菌乳中的应用

Antibacterial effects of antibacterial peptide cp1 on Bacillus cereus and its application in pasteurized milk

目的探究抗菌肽cp1对蜡样芽孢杆菌的抑菌作用,并进一步分析抗菌肽cp1在巴氏杀菌乳中的应用。方法以蜡样芽胞杆菌为研究对象,通过测定抑菌圈直径(diameter of inhibition zone,DIZ)、最小抑菌浓度(minimal inhibitory concentration,MIC)、最小杀菌浓度(minimum bactericidal concentration,MBC)评价抗菌肽cp1对蜡样芽胞杆菌的抑菌效果。通过分析生长曲线、细胞内三磷酸腺苷(adenosine triphosphate,ATP)、膜电位、内容物渗出和细胞形态的变化,来揭示可能的作用机制。在此基础上,并探究抗菌肽cp1在巴氏杀菌乳贮藏中的应用。结果当抗菌肽cp1质量浓度为10μg/mL时,其对蜡样芽胞杆菌的DIZ为(16.19±1.29)mm;抗菌肽cp1对蜡样芽孢杆菌的MIC、MBC分别为4μg/mL和8μg/mL;当抗菌肽cp1质量浓度为2 MIC时,蜡样芽胞杆菌几乎不生长;抗菌肽cp1导致细胞内ATP含量降低,细胞膜超极化,细胞液(包括核酸和蛋白质)漏出,细胞形态破坏;在巴氏杀菌乳中添加1MIC抗菌肽cp1对乳感官均无显著影响,且4℃条件下抗菌肽cp1可有效抑制蜡样芽孢杆菌的生长,将其保质期至少延长到12 d。结论抗菌肽cp1对蜡样芽孢杆菌具有较强的抑菌效果,具有延长巴氏杀菌乳货架期的潜力。

Objective To investigate the antibacterial effects of antibacterial peptide cp1 on Bacillus cereus,further analyze the potential application of antibacterial peptide cp1 in pasteurized milk.Methods Bacillus cereus was employed as the subject of research.The inhibitory effect of the antibacterial peptide cp1 on Bacillus cereus was assessed through the measurement of the diameter of inhibition zone(DIZ),minimal inhibitory concentration(MIC),and minimum bactericidal concentration(MBC).The potential mechanisms of action were elucidated by analyzing growth curves,intracellular adenosine triphosphate(ATP)concentration,membrane potential,substance leakage,and changes in cell morphology.Furthermore,the application of antibacterial peptide cp1 in the storage of pasteurized milk was explored.Results At a mass concentration of 10μg/mL,antibacterial peptide cp1 exhibited a DIZ of(16.19±1.29)mm against Bacillus cereus.The determined MIC and MBC values were 4μg/mL and 8μg/mL,respectively.Bacillus cereus exhibited negligible growth at a antibacterial peptide cp1 mass concentration equal to 2 MIC.The peptide caused a decrease in intracellular ATP levels,hyperpolarization of the cell membrane,leakage of cellular fluids(including nucleic acids and proteins),and cell morphological disruption.The addition of 1 MIC of antibacterial peptide cp1 to pasteurized milk had no significant impact on the sensory attributes of the milk and effectively inhibited the growth of Bacillus cereus at 4℃,extending its shelf life to at least 12 days.Conclusion The antibacterial peptide cp1 demonstrates potent inhibitory effects against Bacillus cereus,indicating its potential to prolong the shelf life of pasteurized milk.