[Objective] The research aimed to analyze the inhibitory mechanism of Sophora japonica n-hexane extract which significantly inhibited Microcystis aeruginosa in the prior research.[Method] S.japonica n-hexane extract was used to treat M.aeruginosa.By inspecting chlorophyll a content,protein content,cell membrane permeability and superoxide dismutase（SOD） activity,the inhibitory mechanism of S.japonica n-hexane extract on M.aeruginosa was analyzed initially.[Result] S.japonica n-hexane extract destroyed the cell membrane system of M.aeruginosa,and increased the cell membrane permeability.The contents of chlorophyll a and protein respectively declined to 10% and 50% of that in the control group after cultivated for 7 d,which indicated the photosynthetic reaction system of M.aeruginosa was destroyed.In addition,under the effect of S.japonica n-hexane extract,SOD activity of M.aeruginosa increased in the early period and decreased in the latter period.[Conclusion] The possible inhibitory mechanism of S.japonica n-hexane extract on M.aeruginosa was destroying the cell membrane to increase the membrane permeability;destroying the photosynthetic reaction system to decrease the contents of photosynthetic pigment and protein;making SOD activity showing the phased variation.
[Objective] The research aimed to discuss the inhibitory effect of Sophora japonica extracts against the growth of Microcystis aeruginosa.[Method] The inhibitory effect of extracted liquid of Sophora japonica leaf against the growth of M.aeruginosa was measured.Moreover,the active component was studied and analyzed initially.[Result] The absolute alcohol extract of Sophora japonica leaf was separated by n-hexane,ethyl acetate,n-butanol and water phases in turn.The polar fractions were found being the majority （〉60%）.The non-polar fraction in n-nexane （about 25%） was found significantly inhibiting the growth of M.aeruginosa.The inhibition rates of fraction in n-hexane at the concentrations of 25 and 50 mg/L against M.aeruginosa in 7 d were higher than 75% and 90% respectively.In addition,chlorophyll a of M.aeruginosa was also destroyed in the presence of the hexane fraction.[Conclusion] The research provided the theoretical basis for preventing and controlling the water bloom of M.aeruginosa.
