中国林蛙皮抗菌肽的提取及其抗菌活性的研究

The study on extraction and antimicrobial activity of antimicrobial peptides from skin of rana chensinensis

采用甲醇提取中国林蛙皮肤中的抗菌肽。并考察了影响抗菌肽粗提物抑菌率的各个因素:如提取时间、提取温度、料液比和pH值等,通过正交试验确定了获取抗菌肽粗提物的最佳条件。即:提取时间为24 h,提取温度为-20℃,提取料液比为1∶25,提取液pH值5.0。此条件下抗菌肽粗提物抑菌率可达75.22%。抗菌肽粗提物对常见的革兰阴性菌和阳性菌以及真菌均有一定抑制效果。对各测试菌株的最低抑制浓度分别为:金黄色葡萄球菌和链球菌为0.25 mg/mL;枯草芽孢杆菌和大肠杆菌为0.5 mg/mL;蜡样芽孢杆菌为1.0 mg/mL;白色念珠菌、酿酒酵母和毛霉为2.0 mg/mL;根霉为4.0 mg/mL。

Antimicrobial peptides were isolated from skin of Rana chensinensis by methanol.Some factor of influence on antimicrobial percentage of antimicrobial peptides crude product was reviewed,such as time,temperature,ratio of sample and extraction solvent and pH.The optimum condition was chosen by orthogonal experiment.The optimum conditions are as follows： The ratio of sample and extraction solvent is 1 ∶25.The extracting solution was disposed for 24 h at-20 ℃.And the pH of extracting solution is 5.0.Under the optimize conditions antimicrobial percentage of antimicrobial peptides can reach 75.22%.Antimicrobial peptides crude product could effectively inhibit the growth of series microorganisms,including Gram-positive bacteria,Gram-negative bacteria and fungus.The MICs of the tested microorganisms were tested as follows： The MIC of Staphylococcus aureus and Streptococcus is 0.25 mg/mL,the MIC of Bacillus subtilis and Escherichia coli is 0.5 mg/mL,the MIC of Bacillus cereus is 1.0 mg/mL,the MIC of Candida albicans,Saccharomyces cerevisia and Mucor is 2.0 mg/mL,the MIC of Rhizopu is 4.0 mg/mL.