Abstract: The ethanol extract and the water extract from Pinus koraiensis(Pinus koraiensis Sieb.et Zucc.) needle were examined for the antimicrobial activities against six bacteria(Staphylococcus epidermidis,Staphylococcus aureus,Bacillus subtilis,Escherichia coli,Pseudomonas aeruginosa,and Proteus vulgaris) and two fungi(Candida albicans,and Aspergillus nigar) by disc diffusion method and micro broth dilution method.The extracts were also studied on their stabilities to temperature and ultraviolet.Results showed that the ethanol extract and the water extract exhibit high susceptivity to gram-positive bacteria,except gram-negative bacteria and fungi.And the ethanol extract shows higher susceptivity than the water extract.The range of minimal inhibitory concentration(MIC) of ethanol extract against gram-positive bacteria is 1.03 to 4.11 mg/ml,while that of the water extract is 2.06 to 4.11 mg/ml.The two extracts from Pinus koraiensis needle are stabile to temperature(≤100 ℃) and ultraviolet.When the temperature reaches 121 ℃,only few microorganisms are affected.So they can be added into food in order to prolong the preservation time.It was also found antibacterial components of Pinus koraiensis needle dissolves in high concentration ethanol,which provides scientific basis for the application of ethanol and water extract from Pinus koraiensis needle as antibacterial preparation in clinic.

Key words: Pinus koraiensis, ethanol extract, water extract, antimicrobial activity