Abstract
Recently, the calcined powder of oyster shells has been found to possess antibacterial activity, and has been considered for use as a bactericidal agent. In this study, calcined shell preparations were made from oysters, scallops, clams and roll shells, and their antibacterial activities were compared using total aerobic counts and E. coli. It was found that the calcined shell calcium from surf clams had the highest activity. Further comparison of activity was made between the calcined surf oyster preparation which was known to have antibacterial activity and the calcined surf clam preparation, and calcined surf clam calcium was found to have higher antibacterial activities against pathogenic Escherichia coli O157 : H7, Pseudomonas aeruginosa and Staphylococcus aureus. The antibacterial activity was due to the strong alkalinity of aqueous solutions of this calcined calcium preparation
