黑水虻抗菌肽对曲霉和沙门氏菌的抑制作用及其营养成分研究

Inhibitory effect of antibacterial peptides from black soldier flies on Aspergillus and Salmonella and their nutritional components

为研究黑水虻抗菌肽对曲霉和沙门氏菌的抑制作用及其营养成分,本试验通过微量肉汤稀释法和分光光度计法对最低抑菌浓度和抑菌曲线进行了比较。结果表明:抗菌肽对沙门氏菌的最低抑菌浓度为2.5 mg/mL,在此浓度下黑水虻抗菌肽对黑曲霉也有较强的抑制效果,处于最低的抗菌肽对沙门氏菌的抑制时间为32 h(P <0.01);使用场发射扫描电子显微镜对黑水虻抗菌肽作用前后病原菌形态进行观察,证明抗菌肽作用于病原菌膜结构,在膜上形成离子通道,造成病原菌内容物流出,从而导致病原菌死亡;采用酸水解和2,4二硝基氟苯柱前衍生高效液相色谱法对抗菌肽氨基酸组成进行分析,结果显示必需氨基酸含量占比约为50%。抗菌肽粗提物具有抑菌作用强,对环境友好,无富集无残留,营养全面等优点,十分适宜作为饲用抗生素的替代物。

In order to study the inhibitory effect of antibacterial peptides from black soldier flies on Aspergillus and Salmonella and their nutritional components.The minimum inhibitory concentration and antimicrobial curves were determined and compared by micro-broth dilution method and spectrophotometer method.The results showed that the minimum inhibitory concentration of antimicrobial peptides against Salmonella was 2.5 mg/mL.At this concentration,the antibacterial peptide of black soldier fly also had a strong inhibitory effect on Aspergillus niger.The antibacterial curves of antimicrobial peptides and oxytetracycline against Salmonella were drawn by spectrophotometer and compared,and the results showed that the inhibitory time of antimicrobial peptides at the minimum inhibitory concentration on Salmonella was 32 h(P<0.01);Field emission scanning electron microscope was used to observe the morphology of pathogenic bacteria before and after the action of antimicrobial peptides in black soldier flies,and it was proved that antimicrobial peptides acted on the membrane structure of pathogenic bacteria and formed ion channels on the membrane,causing the content of pathogenic bacteria to flow out,resulting in the death of pathogenic bacteria;The amino acid composition of antimicrobial peptides was analyzed by acid hydrolysis and 2,4-dinitrofluorobenzene pre-column derivatization high performance liquid chromatography.The results showed that the essential amino acid content accounted for about 50%.Antibacterial peptide crude extract had the advantages of strong antibacterial effect,environmental friendliness,no enrichment and no residue,and comprehensive nutrition.It was very suitable as a substitute for feed antibiotics.