鲟鱼表皮粘液抗菌肽的分离鉴定及抑菌活性分析

Isolation,Identification and Antimicrobial Activity Analysis of Antimicrobial Peptides from Epidermis Mucus of Sturgeon

为了探究鲟鱼表皮粘液的抑菌活性,本研究首先分析了粘液的基本成分及氨基酸组成,粗提了粘液中的抑菌物质,验证了其抑菌活性,探究了其对三文鱼的保鲜效果;其次通过固相萃取、凝胶过滤色谱和反相高效液相色谱从粘液中纯化了具有抑菌活性的组分,并进行了肽序列鉴定;最后人工合成抗菌肽,验证了其抑菌活性。结果表明,鲟鱼表皮粘液的主要成分为蛋白质,含量为47.44%±0.59%,总氨基酸含量为459.68 mg/g,其中碱性氨基酸及疏水性氨基酸含量较高;抗菌肽粗提物对枯草芽孢杆菌表现显著抑菌活性,50 mg/mL的抗菌肽粗提物显著抑制了三文鱼保鲜过程中微生物的生长和蛋白质降解;液相色谱纯化后最高活性组分对枯草芽孢杆菌的抑菌率达92.40%±4.50%,对大肠杆菌的抑菌率为75.43%±5.02%;鉴定出两种新型抗菌肽序列HSETLHDV和PLTDWQL;人工合成抗菌肽对枯草芽孢杆菌、大肠杆菌及希瓦氏菌均具有明显抑制作用。本研究为探索鲟鱼粘液的抗菌价值提供理论依据,为天然保鲜剂的开发及应用奠定基础。

To explore the antimicrobial activity of epidermis mucus,the basic components and amino acid composition were analyzed and the antimicrobial substances in the mucus were extracted in this study.Their antimicrobial activity,preservation effects on salmon were explored.The components with antimicrobial activity were isolated and purified by solid phase extraction,gel filtration chromatography and reverse phase high performance liquid chromatography.And the peptide sequences were identified.Then,the antimicrobial peptides were synthesized accordingly and their antimicrobial activities were verified.The results exhibited that the main composition of epidermis mucus of sturgeon was protein with 47.44%±0.59%.The total amino acid content was 459.68 mg/g,with a high content of basic amino acids and hydrophobic amino acids.The crude antimicrobial peptide exhibited significant antimicrobial activity against Bacillus subtilis.Crude antimicrobial peptide(50 mg/mL)significantly inhibited the growth of microorganisms and protein degradation during salmon preservation.The highest active component after final liquid chromatography purification exhibited an inhibition rate of 92.40%±4.50%against Bacillus subtilis and 75.43%±5.02%against Escherichia coli.The sequences of novel peptides were identified as HSETLHDV and PLTDWQL.The synthetic antimicrobial peptides of sturgeon epidermis mucus had obvious inhibitory effects on Bacillus subtilis,Escherichia coli and Shewanella baltica.Therefore,this study would provide a theoretical basis for exploring the antimicrobial value of sturgeon mucus and lay a foundation for the development and application of natural preservatives.