EXPERIMENTAL STUDY ON THE INHIBITION EFFECT OF EXTRACTS FROM PISTIA STRATIOTES LINN. ON THE GROWTH OF MICROCYSTIS AERUGINOSA

The current study obtained four different allelopathic crude extracts from Pistia stratiotes Linn, a aquatic floating plant with higher efficiency on nitrogen and phosphorus removal, using ethanol ultrasonic extraction. These four, allelopathic extracts (0.1 g/L) inhibited the growth of Microcystis aeruginosa (FACHB-911) for 40%, 69%, 40% and 35% after 5 days treatment, respectively. Extracts were further purified through the method of acidic alumina column chromatography separation, which had inhibition rates 12%, 11%, 33 and 41% after 5 days treatment, respectively. Interestingly, one group of allelopathic fraction had 80% inhibition rate after 5 days treatment. The results of gas chromatography-mass spectrometry (GC-MS) analysis revealed that the extracts from P. stratiotes mainly contained two antialgal compounds including P-toluene sulfonic acid methyl ester and stearic acid amide.