花椒籽蛋白抗菌肽的抑菌作用及其稳定性研究

本研究采用菌落计数法对花椒籽蛋白抗菌肽的抑菌效果及稳定性进行了研究。结果表明:抗菌肽对大肠杆菌、沙门氏菌、枯草芽孢杆菌和金黄色葡萄球菌均具有抑制作用;抗菌肽的抑菌活性随浓度的升高而增强;经不同温度、加热时间处理后,抗菌肽的抑菌活性与对照相比无显著差异(p0.05);抗菌肽在经p H 2.0~12.0处理后仍有抑菌活性,p H 2.0时的抑菌率最低(58.13%),p H 12.0时的抑菌率最高(79.17%);随着金属离子浓度的增加,经K+、Ca2+和Fe3+处理后的抗菌肽的抑菌活性分别呈降低、增加、变化平缓的趋势,经0.1 mol/L K+处理后的抗菌肽的抑菌活性明显增强;经有机溶剂处理后,抗菌肽的抑菌活性有所降低;经吐温20、吐温80处理后,抗菌肽的抑菌活性极显著增强(p0.01),SDS对抑菌活性的增加不显著。因此,抗菌肽具有很好的热、酸碱、金属离子和有机溶剂稳定性,而表面活性剂(吐温20、吐温80)能使抗菌肽的抑菌活性显著增强。

Antibacterial Activity and Stability of Antimicrobial Peptides in Chinese Prickly Ash Seed Proteins

Colony count method was used to evaluate the stability of antimicrobial peptides from prickly ash seed proteins and their antimicrobial activity. The results revealed that the peptides showed inhibitory effects on Escherichia coli, Salmonella, Bacillus subtilis, and Staphylococcus aureus. The antimicrobial activity of these peptides increased in a dose-dependent manner. After treating at different temperatures and heating time, the antibacterial activity of the peptides showed no significant differences when compared with that of the control (p > 0.05). The peptides retained excellent antibacterial activity even after the treatment at pH values between 2.0 and 12.0, with lowest activity at pH 2.0 (58.13%) and the highest activity at pH 12.0 (79.17%). With increasing concentration of metal ions, the antibacterial activity decreased, increased, and changed slightly after treatment with K+, Ca2+, and Fe3+, respectively. However, the antibacterial activity increased significantly after treatment with 0.1 mol/L K+. The antibacterial activity decreased slightly after treatment with organic solvents, whereas it increased significantly (p < 0.01) when treated separately with Tween 20 and Tween 80, while the increase was not significant after treatment with SDS. Therefore, the antimicrobial peptides had excellent stability against changes in temperature, pH, metal ion content, and organic solvent concentration, while surfactants (Tween 20 and Tween 80) could significantly improve the antibacterial activity.