Antibacterial Activity Of Calcined Shell Material

Recently, in scallop harvesting districts, large amounts of shell are heaped near the seaside,which creates serious environmental problems, so an efficient and pollution-free and non-toxicantimicrobial agent which is made by shell as a raw material has become a research focus.Application of calcined shell material has not only improved the antibacterial efficiency, but alsohelps to solve the problem of environmental pollution by shell and effective use of resources.However, there have been few quantitative studies on the antibacterial activity of calcined shellmaterial.Using E. coli and Staphylococcus aureus as the test strain and calcined shell material as theobject of study, this paper discusses the antibacterial properties of calcined shell material as wellas some factors affecting antibacterial effect. The main contents and conclusions of the study areas follows:1、Through calculating rate of weight loss of calcined shell material, the shells are calcinedcompletely when the shells are fired more than2h. And the antibacterial effect of antibacterialagent is demonstrated by using the naked eye observation, Gram staining, plate culture method.2、By oscillation method, diffusion method for the antibacterial circle experiment and theMIC test and antibacterial rate determination experiment, it is showed that the antibacterial effectis not obvious or less when the concentration of calcined shell material is lower, but the calcinedshell material in the higher concentration has a medium or strong antibacterial effect. Under thesame conditions, the MIC of Staphylococcus aureus is less than the MIC of E. coli, and theantibacterial circle diameter and the antibacterial rate of Staphylococcus aureus are greater thanthe antibacterial circle diameter and the antibacterial rate of E. coli, which indicates that theantibacterial effect of the antibacterial agent on Staphylococcus aureus is superior to theantibacterial effect on E. coli.3、The calcining temperature, calcining time and calcined shell material concentration arestudied as experiment factors to optimize the best antibacterial conditions. The results showedthat the antibacterial circle diameter of E. coli and Staphylococcus aureus increases with thecalcining temperature, calcining time and calcined shell material concentration increase when thecalcining temperature is lower than1100℃, calcining time is less than2h, calcined shellmaterial concentration below3.2%. That manifest the three experiment factors have a significantimpact on the antibacterial effect calcined shell material, antibacterial effect enhances as thecalcining temperature, calcining time and calcined shell material concentration increase. And thebest antibacterial conditions are as follows: the calcining temperature is1100℃, the calciningtime is2h,the calcined shell material concentration is3.2%.