reportedthat crude chitin from crab shells did not show any antimicrobialactivity but chitin from shiitake stipes and mushroom exhibited abetter inhibitory effect on bacterial growth than chitin from crabshells. After purification, chitosan from shiitake stipes and crabshells exhibited excellent antimicrobial activities against speciesof pathogenic bacteria. However, chitosan from shiitake stipes wasslightly more effective than that from crab shells. It was demon-strated by Byun et al. [6] that chitosans prepared from ground andentire crab leg shell exhibited drastic differences in their physic-ochemical and functional characteristics. For example, chitosanprepared from ground shell had significantly higher nitrogen con-tent, degree of deacetylation, solubility, viscosity and antibacterialactivity than chitosan prepared from entire shell.Antibacterial activities of oligomer and polymer