Hydrochar synthesis of from waste human hair, incorporation with phenolic extract of Morus alba and evaluation as a natural anti-Staphylococcus aureus agent

Abstract

In this study, an aqueous extract of Morus alba (M. alba) was incorporated into hair hydrochar (HH) to enhance the anti-Staphylococcus aureus activity. The bacterial adsorption capacity of HH alone was tested using the modified TTC-DRA (dehydrogenase relative activity) assay and imaged with Scanning Electron Microscope (SEM). The loading efficiency, Fourier-transform infrared spectroscopy (FT-IR) analysis, and anti-S. aureus performance of M. alba extract (MAE) loaded hydrochar (HH+MAE) was investigated. Concentration-dependent inhibitions of HH and HH+MAE on S. aureus inoculated on the artificial skin surface were studied for the first time. In the agar well diffusion test, the highest inhibition zones (IZs) of HH and HH+MAE were 3.4 mm and 20.1 mm on S. aureus. The decrease in the number of S. aureus were 0.39 CFU/cm2, 0.42 CFU/cm2 and 0.49 CFU/cm2 at the 10 mg/mL, 20 mg/mL and 40 mg/mL of HH, respectively, while log reduction were 0.81 CFU/mL, 0.83 CFU/ cm2 and 1.1 CFU/ cm2 at the 10 mg/mL, 20 mg/mL, and 40 mg/mL of HH+MAE, respectively. The percent reduction (%) of S. aureus treated with 40 mg/mL of HH was found as 67.7%, while was 92.2% when treated with 40 mg/mL of HH+MAE (p < 0.05). As a result, the anti-S. aureus activity of HH containing bioactive components enriched with MAE extract was strengthened. HH+MAE can be suggested for use in the treatment of skin disorders in which S. aureus is dominant.