| In order to develop natural antibacterial agents, the antibacterial activity of Aspergillus niger xj was investigated. After being cultured in PDA liquid medium, mycelia was under heating reflux extraction with 90% ethanol (EtOH). Removal of EtOH under reduced pressure gave a residue, to which water was added and then extracted with petroleum ether (P.E) and ethyl acetate (EtOAc). In
vacuo evaporation of the solvents yielded three crude extracts. The fermentation broth was directly extracted by P.E and EtOAc. In vacuo evaporation of the solvents also yielded three crude extracts. Then the the disc diffusion method was used to measure the antibacterial
activity of these extracts. Results showed that at the concentration of 50 mg/mL, the ethyl acetate extract of fermentation broth exhibited apparent inhibitory effect against Staphylococcus aureus, while the petroleum ether extracts of mycelia and fermentation broth showed moderate antibacterial activity, but the rest were not. |
