Antimicrobial Characteristics of Heated Eggshell Powder

Abstract

Eggshells have high bioavailability and can be used as a source of calcium. The main component is CaCO 3 , which, when heated, is converted to CaO. Seashells are also mainly composed of CaCO 3 and were previously found to exhibit antimicrobial activity after being heated. In this study, heated eggshell powder HESP was found to have antimicrobial activity against bacterial vegetative cells, fungi and bacterial spores. Parameters, such as the minimum inhibitory concentration, were determined with kinetic analysis using an indirect conductimetric assay. Moreover, HESP was able to kill the Bacillus subtilis spores. There were no significant differences in the activity between HESP, heated scallop-shell powder and pure CaO. The MIC values for HESP against bacteria and fungi were 0.29-0.43 and 1.3-1.5 mg/mL, respectively. Against B. subtilis spores, a reduction of two orders of magnitude of viability was confirmed following 20 min of treatment at 10 mg/mL at 60 . The active oxygen generated from the HESP slurry was examined with chemiluminescence. The intensity of this increased with increasing concentrations of the HESP slurry. This suggests that HESP could be used as a natural antimicrobial agent. Although a high pH is the main contributor to this antimicrobial activity, active oxygen species generated from HESP are likely to be the main antimicrobial agents..

The Impact of UnCalcined & Calcined Eggshell Powder as BioFiller for Polylacticacid

“…Furthermore, the results of bactericidal against E.coli bacteria were lower for PLA and its composites as compared with staph (34, 45, 52 and 61) % for PLA and its composites. This results agreed with [30] that explained antibacterial activity of PLA against grampositive more than gram-negative because of E. coli has proteins, lipopolysaccharides (LPS) and lipidsin the membrane of his cell which supplied effective protection against biocides, while [31] their results in its agreed with our results when explained ability of eggshell to inhibit the growth of gram-positive and negative bacteria and this ability increased when the concentration was increased too. The mechanism action of eggshell belongs to converted CaCO3 to CaO when it's heated and the hydration process of CaO, which produces alkaline solution conditions, is viewed as an essential EDP activity component.…”

Antibacterial Properties of Biobased Polyester Composites Achieved through Modification with a Thermally Treated Waste Scallop Shell

“…However, there were 0.29/0.21 and 0.45/0.34 cm inhibition zones in E. coli / S. aureus cells of the MPLA/TWWSSP (3 wt %) (9) and MPLA/TWWSSP (5 wt %) (10) composites, respectively. These results likely resulted from the presence of Ca­(OH) 2 , and CaO, , and more specifically from the release of hydroxyl ions and active oxygen species generated at the TWWSSP surface, which inactivated the microorganisms.…”

A comparative study on in vitro behavior of calcium silicate ceramics synthesized from biowaste resources

“…The antimicrobial activity of NCS ceramics could be due to calcinated eggshells. It is reported that calcium oxide produced in eggshell that is calcined at a temperature of about 900°C can impart antimicrobial activity to the composition . Bacterial adhesion to the implant material is the main cause of implantation infections that lead to the failure of implanted material.…”

“…It is reported that calcium oxide produced in eggshell that is calcined at a temperature of about 900°C can impart antimicrobial activity to the composition. [52][53][54] Bacterial adhesion to the implant material is the main cause of implantation infections that lead to the failure of implanted material. Several studies have been reported on ion-based modification by doping the antibacterial agent (Ag, Cu, and Zn) for improving antimicrobial activity of calcium silicate ceramics.…”