The Hypsizigus marmoreus has been used as medicinal and food source in worldwide. Viridans Streptococci, which include Streptococcus sanguinis and Streptococcus gordonii, are pioneer oral bacteria that initiate dental plaque formation. This study was to investigate the antimicrobial activity of Hypsizigus marmoreus Extracts. Antimicrobial activity of extracts were tested against pathogenic bacteria (Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus sanguinis and Streptococcus gordonii) by paper disc methods. The Hypsizigus marmoreus Extracts were extracted with 80% methanol. The 80% methanol extracts of Hypsizigus marmoreus Extracts showed antimicrobial activity against S. sanguinis and S. gordonii. The 80% methanol extract of Hypsizigus marmoreus Extracts were fractioned by hexane, chloroform, ethylacetate and buthanol. The ethylacetate fraction of Hypsizigus marmoreus Extracts showed strong antimicrobial activity against S. sanguinis and S. gordonii with minimum inhibitory concentration (MIC) range of 0.8-1 mg/ml. Especially, the 80% methanol extract and ethylacetate fraction of Hypsizigus marmoreus Extracts were inhibited the biofilm formation of S. sanguinis and S. gordonii at a concentration of 1.0 mg/ml. These results suggest that Hypsizigus marmoreus extracts can be developed as a potent antimicrobial agent.

• Soo Cheol Kim(Dept. of Pharmaceutical Engineering, Gyeongnam National University of Science and Technology, Jinju 660-758, Korea,)
• Jong Ok Kim( Namkyung Co., Ltd, Cheongdo-gun, Gyeongbuk 714-841, Korea) | Jong Ok Kim
• Soo Jeong Cho( Dept. of Pharmaceutical Engineering, Gyeongnam National University of Science and Technology, Jinju 660-758, Korea,) | Soo Jeong Cho