Abstract:

The antibacterial activity of ethanol extracts from 27 plant spices was tested against P1 strain isolated from deteriorated salted duck. In order to obtain the highest antibacterial activity, ethanol extracts from 3 plant spices with higher antibacterial activity were compounded and the compound proportion was optimized in terms of antibacterial activity against P1 strain and other bacteria, including Staphylococcus aureus, Pseudomonas sacastanoi, Salmonella, Escherichia coli, Bacillus subtilis. Subsequently, the optimal compound antibacterial ethanol extracts were evaluated for minimum inhibitory concentration (MIC) and effect of temperature on their biological activity. Results showed that ebony, clove and liquorice were chosen due to high antibacterial activity of ethanol extracts and their compound with the mixing proportion of 1:8:1 (V/V) yielded significantly higher antibacterial activity than individual ebony extract. Moreover, no obvious change was observed in inhibitory effect of the compound ethanol extracts when exposed to high temperature (up to 100 ℃) for a long time.

Key words: plant spices, compound, inhibition zone, minimum inhibitory concentration, temperature