Abstract:

This study investigated the antibacterial activity of different extracts from T. viride fermentation broth and its
damage to the cell membrane of Staphylococcus aureus. The antibacterial activity was evaluated by Oxford plate method, the
proportion of Staphylococcu aureus cell lysis was determined and the damage to the cell membrane was evaluated by determining
membrane permeability and SDS-PAGE. Petroleum extract, ethyl acetate extract and n-butanol extract from T. viride fermentation
broth exhibited antibacterial activity, especially n-butanol extract (d = (25.27 ± 0.65) mm, MIC = 0.625 mg/mL). After treated
by n-butanol extract, the proportion of cell lysis, electric conductivity, protein and reducing sugar content of Staphylococcus
aureus culture suspension increased significantly. SDS-PAGE assay demonstrated that n-butanol extract could interfere with
cell membrane protein expression in Staphylococcus aureus. In addition it could damage the structure of cell membrane,
resulting in an increase in the cell membrane permeability and disorders of cell membrane function. Thus, the growth of
Staphylococcus aureus was inhibited.

Key words: Trichoderma viride, fermentation broth, extracts, Staphylococcus aureus, cell membrane, damage