大肠杆菌诱导黄粉虫产生抗菌肽的提取及抑菌活性的测定

为了探究大肠杆菌对黄粉虫抗菌肽的诱导效果,采用不同方法处理的大肠杆菌诱导黄粉虫产生抗菌肽,经过诱导的黄粉虫于12、24、36、48、60、72 h时,分别粗提其中的抗菌肽,测定其浓度和抑菌活性,同时,统计了大肠杆菌诱导的黄粉虫体内细菌含量。结果表明:经诱导各个时间点的黄粉虫抗菌肽浓度均显著高于未诱导的黄粉虫组(P0.05),且在诱导48 h时产生的抗菌肽浓度最高,大肠杆菌和灭活大肠杆菌诱导黄粉虫产生的抗菌肽对3种细菌的抑菌直径均显著大于未诱导组,且对大肠杆菌抑菌力高于金黄色葡萄球菌和沙门氏菌(P0.05),大肠杆菌诱导48 h后的黄粉虫中细菌含量为9.5×10~4 CFU/g,低于国家规定标准饲料中细菌总数最低值2×10~6 CFU/g。提示,用大肠杆菌诱导黄粉虫能刺激黄粉虫产生高表达量的抗菌肽,并对大肠杆菌具有较强的抗菌性能且具有一定的安全性。

The Extraction of Antimicrobial Peptide of Tenebrio molitor Induced by E.coli and the Determination of Its Antibacterial Activity

In order to study the inductive effects of antimicrobial peptides （AMPs） produced in Tenebrio molitor induced by E. coli.E.coli was used to induce Tenebrio molitor to produce antimicrobial peptide by different treatments.AMPs were extracted from Tenebrio molitor at 12 h,24 h,36 h,48 h,60 h,72 h,respectively,and their concentration and antibacterial activity were measured.Simultaneously,bacteria contents in vivo were also measured.The results showed that the concentration of AMPs in induction groups was significantly higher than the control groups （P〈0.05）,which was up to the highest at 48h.The diameter of inhibiting groups was significantly bigger than control Staphylococcus Aureus and Salmonella, which showed that antibacterial peptide had a higher bacteriostatic effect on E.coil （P〈0.05）.Furthermore, the amount of bacteria was 9.5x104 CFU/g in induction group of 48 h which were lower than the national standard minimum level of 2x106 CFU/g.Hence, the AMPs of Tenebrio molitor could be enhanced after induced by E.coil.A further advantage was that the products had a better antibacterial activity on E.coil and were much safer.