Abstract: Antimicrobial peptides are found both in prokaryotes and eukaryotes.They possess low molecular weight and are characterized by compact structures,thermal stability and potent antimicrobial activity.Since these peptides are directly gene-encoded,it is possible to modify their stl’ucture by mutagenesis to produce structure analogues with an expanded spectrum of antimicrobial activity.Futhemore.the production of these peptides could enable yield improvement to make accessible t’or industrial application and to reduce the processing costs by using optimized isolation procedures.They might be useful as etyective natural food preservertives because of their good properties.

Key words: Antimicrobial peptides Prodaryotes Eukaryotes