大肠杆菌刺激蝇蛆产生抗菌肽浓度和抑菌活性的测定

目的]确定大肠杆菌菌液刺激蝇蛆产生浓度高、活性强的抗菌肽时间和蝇蛆饲喂家禽的安全性。方法]采用不同浓度的大肠杆菌菌液分别与麸皮混合饲喂蝇蛆,于10、24、48 h分别收集存活蝇蛆并对其粗提取抗菌肽,通过考马斯亮蓝法和抑菌试验分别测定各试验组抗菌肽粗提液的浓度和抑菌力,同时用CFU计数法测定细菌培养的家蝇幼虫的细菌含量以确定其作为绿色抗生素的安全性。结果]浓度为3.0×107cfu/ml的大肠杆菌作用24 h的蝇蛆组产生的抗菌肽浓度最高、活性最强,且蝇蛆体内细菌含量为1.6×105cfu/g,低于国家规定的饲料细菌标准含量最低值(2×106cfu/g)。结论]为进一步利用动物死尸、畜禽粪便生物转化蝇蛆产生大量安全、浓度高且活性强的蝇蛆抗菌肽作为绿色抗生素运用于禽类养殖业奠定了基础。

E.coli Stimulating Maggot Antimicrobial Peptide Concentration and Antibacterial Activity Determination

Objective] In order to determine the time of antimicrobial peptides(AMPs) which has high concentration and strong antibiotic activity stimulated by E.coli and the security of feeding poultry with maggot.Method] Maggot was fed with different concentrations of E.coli bacteria solution mixed with bran.Survival maggot was collected and the AMPs was extracted crudely after 10 h,24 h,48 h respectively.Then the concentration of AMPs and antibiotic activity were determined by coomassie brilliant blue and antibacterial test.The safety of feeding poultry directly was measured by CFU counting method.Result] The result showed: AMPs with highest concentration and strongest antibiotic activity was induced by 3.0 × 107 cfu/ml E.coli for 24 h and the bacterial content of maggot in vivo was 1.6 × 105 cfu/g,which was less than the minimum value of national feed standard(2 × 106 cfu/g).Conclusion] The study will lay a fundation for utilizing maggot from animal corpses,livestock and poultry manure to produce a large amount of safety,high concentration and strong activity maggot antimicrobial peptide,which could be applied in livestock breeding as green antibiotics.