Abstract: To discover inhibitors of enoylpyruvate transferase with antibacterial activity a batch of 2490 extract or fraction samples from plants and animals belonging to 169 families, 560 genera and 916 species were tested on enoylpyruvate transferase bioassay in 96-well microtiterplates. Finally 309 samples, which belong to 80 families, 169 genera and 218 species, showed inhibitory activity at 96.15ug/ml, in which 14 samples showed IC50 at=<10.00ug/ml, 40 samples showed IC50 at 10.01-30.00ug/ml, 83 samples showed IC50 at 30.01-50.00ug/ml and 172 samples showed IC50 at 50.01-96.15ug/ml. It is indicated that this in-vitro bioassay is convenient, stable, rapid, sensitive and effective in searching for antibacterial activity samples from natural sources.

Key words: Antibacterial activity screening