Hydrochar-Enriched Myrtus communis Emulsion Gel: Antimicrobial Efficacy Against Bacterial Contaminants on Inoculated Carcass Skin

Abstract This study used chicken nail hydrochar (CH) to make a matrix environment in Mrytus communis ( M. communis ) emulsion gel (MEg). The inhibition potential of MEg containing CH against Acinetobacter baumannii (A. baumannii) and Enterococcus faecalis (E. faecalis) pathogens and the characterization were investigated. Characteristics and surface analysis of hydrochar-based M. communis emulsion gel (H-MEg) were analysed using FT-IR and SEM. M. communis essential oil (EO) was emulsified using tween 80, gelified using collagen and then immobilized into the hydrochar using a lyophilizer. In the antibacterial activity test, inhibition zones of MEg and H-MEg against A. baumannii were 7.26, and 9.1, respectively. E. faecalis was inhibited with 47.81 and 5.82 mm by MEg, and H-MEg, respectively. The highest reduction at the final of 30 min for A. baumannii inoculated carcass skin was 1.3 CFU/cm 2 , 95.9% for H-MEg ( p < 0.05). The zeta potential, conductivity and viscosity of H-MEg were -14.5 ± 0.4 mV, 0.0012, and 0.8872, respectively. As a result, the addition of CH to MEg-containing microdroplets enabled the composite to become fully stable. The hydrochar itself did not have antimicrobial effects, while the bioactive M. communis emulsion gel enhanced the functionality of chicken nail waste-based hydrochar. H-MEg obtained from chicken nail waste can be used for treatment purposes in infections where A. baumannii ve E. faecalis bacteria are active. Graphical Abstract