Isolation And Purification Of Mytilus Edulis Antibacterial Peptides

Antibacterial peptide is a kind of broad spectrum and low molecular peptide. People now pay more and more attention on antibacterial peptide, since it is not easy for bacterical to gain drug resistance. In this paper, antibacterical peptides were extracted directly from mussel. The natural activity of mussel antibacterial peptide can be kept well using this method, and the biological properties were then studied.First of all, the study has achieved a method of extraction from mussel antimicrobial peptides. Comparing with different concentrations of ammonium sulfate, ethanol and acetic acid method, the antimicrobial activity were identified. The results showed that the concentration of acetic acid was 0.5%, we can get antibacterial peptides wth high antibacterial activity and high protein content.Secondly, the crude product was purified. Comparison the antibacterial activity of different gel filtration chromatography Sephadex G-25, Sephacryl S-300and Sephacryl S-100, the column Sephacryl S-100 was the best with 1% acetic acid eluntion, flowing rate 1.3ml/min and the lOmL sample volume. The purified antibacterial peptides had a high antibacterial activity with the diameters of inhibition zone all above 15mm.Finally, the biological activity of the antibacterial peptides were investigated. The antibacterial spectrum of antibacterial peptides were studied using Escherichia coli, Staphylococcus aureus, Micrococcus, Aeromonas hydrophila, Pseudomonas aeruginosa and Streptococcus salivarius. The results showed that antibacterial peptides had broad-spectrum antibacterial activity. Its minimum inhibitory concentration was below 300μg/mL. The minimum inhibitory concentration of Micrococcus was only 50μg/mL, illustrating that the antibacterial peptides have a high efficiency to inhibit the bacterial; Denaturing gel electrophoresis of proteins has received a single band and it can prove that the antibacterial peptides have low molecular weight. Studying on protein temperature and pH stability, the results showed that the mussel antibacterial peptides had a high resistance of acid.