Primary Studies On Antibacterial Peptides From Tilapia Wastes Enzymatic Hydrolysates

Antimicrobial peptide is one kind of low molecular weight polypeptides widely exist in organism body, has the strongly antimicrobial activity , the broad spectrum antibiotic, the synthesis and the sterilization speed quick, not easy to have drug tolerance, it will be the new antimicrobial preparation .The tilapia mossambica lives for a long time in various microorganism water environment, in order to survives to cause it to form the effective defense functions ntimicrobial peptides.In order to get high activity antimicrobial peptides, development tilapia wastes mossambica Intensive processing, enhances the combined earnings and reduction environmental pollution; afford the base theory for development tilapia wastes mossambica Intensive processing. This research take the tilapia wastes as raw material, after the experiment we get the best enzymolysis condition: choose 2709 Alkaline Protease,the temperature is 55℃, pH is 9.0, the concentration of substrates is 10%, enzyme quantity is 4000U/g,enzymatic hydrolysis 5h. Under 4℃the enzymatic Hydrolysate centrifuging as a speed 12000 rpmin lasted 20 min, Supernate was ultrafiltrated membrane with 1 ku molecular weight cut-off, leaves the Molecular Weight was less than 1 ku raw peptides components,and then through SP-Sepharose Fast Flowand FPLC to got two antimicrobial peptides F21 and F22 with high antimicrobial activity, their Molecular Weight are 528.6 and 504.2.The MIC of F21 on Bacillus subtilis,, Escherichia coli and Staphylococcus aureus are 3.44μg/ml,4.72μg/ml and 6.54μg/ml. The MIC of F22 on Bacillus subtilis,, Escherichia coli and Staphylococcus aureus are 3.28μg/ml,2.55μg/ml and 7.31μg/ml.F21 ans F22 rae very similar in isoelectric point,hydronium characteristic and drainage characteristic. They also have heat resistance. It's the first time to get high activity antimicrobial activity antimicrobial peptides through enzymatic hydrolysis tilapia wastes.