Abstract:It was to investigate the effect mechanism of tachyplesin I on Proteus vulgaris. The study on the inhibition concentration of tachyplesin I, the plasma membrane permeability and electric charge of Proteus vulgaris, the activity of proteases were secreted by Proteus vulgaris and the stability of tachyplesin I in the nutrient broth medium where cultured Proteus vulgaris. Results indicated that the MIC and MBC were 40-80 and 80 μg/mL, respectively. The membrane permeability and electric charge of Proteus vulgaris would be increased with the concentration of tachyplesin I increasing. The proteinase activity which secreted by Proteus vulgaris would be increased when the concentration of tachyplesin I less than 40 μg/mL, but it presented downward trend when more than 60 μg/mL. The concentration of tachyplesin I in the medium that trained the bacterial would reduce. Tachyplesin I could inhibit growth of the Proteus vulgaris, the effect mechanism related to damage the membrane permeability of them.