Study on extraction of 3-30 kD antimicrocial peptides and its antibacterial activity

In order to isolate and purify the 3 ~30 kD antimicrobial peptides from earthworm and examine its antibacterial activity.The antimicrobial peptide of earthworm were produced by lightning stroke,and isolate the 3~30 kD antimicrobial peptides by ultrafiltrating,concentration and desalinization.Using the SP-Sepharose Fast Flow ion exchang chromatography to remove most of the hybridprotein and Sephadex G-50 gel filtration chromatography to precisely abstracte 3~30 kD antimicrobial peptides which have two wave crest of protein named H1,H2.Their proteinic concentration are 6.82 and 7.46 mg/μl and the molecular mass are between 5.856~7.823 kD and 14.4-20.10 kD.The antimicrobial tests reveal that the antibacterial activity of H1 and H2 is great.Antibacterial activity of H1 on Bacillus subtilis,Staphyloccocus aureus Rosenbach,Pasteurella,E.Coli is obvious.While the antibacterial activity of H2 is good on Pasteurella,E.Coli,Bacillus subtilis.In addition,The antibacterial activity of H1 is better than H2.