Blooms of freshwater cyanobacteria have caused increasing eco-environmental problems in recent years. Recently, plant extracts have been considered as attractive alternative algicides for algal bloom treatment. The present work presented the effect of three different extracts (ethanol, water and methanol) prepared from Eupatorium fortunei Turcz at concentrations of 500 and 200 µg/mL on the growth of Microcystisaeruginosain a 10-day experiment. | Vietnam Journal of Science and Technology 55 (4C) (2017) 103-108 INHIBITORY EFFECT OF DIFFERENT EUPATORIUMFORTUNEI TURCZ EXTRACTS ON THE GROWTH OF MICROCYSTIS AERUGINOSA Pham Thanh Nga1, 2, Pham Huu Dien1, Nguyen Van Quyen1, Tran HoaiThuong1, Le Thi Phuong Quynh3, Nguyen Tien Dat4, Duong ThiThuy5, Dang Dinh Kim5, * 1 Hanoi National University of Education,136 Xuan Thuy, Cau Giay, Ha Noi, Viet Nam 2 Graduate University of Science and Technology, VAST, 18 Hoàng Quốc Việt, Ha Noi, Viet Nam 3 Institute of Natural Products Chemistry, VAST, 18 Hoang Quoc Viet, Ha Noi, Viet Nam 4 Center for Research and Technology Transfer, VAST, 18 Hoang Quoc Viet, Ha Noi, Viet Nam 5 Institute of Environmental Technology, VAST, 18 Hoang Quoc Viet, Ha Noi, Viet Nam * Email: Received: 30 June 2017; Accepted for publication: 20 October 2017 ABSTRACT Blooms of freshwater cyanobacteria have caused increasing eco-environmental problems in recent years. Recently, plant extracts have been considered as attractive alternative algicides for algal bloom treatment. The present work presented the effect of three different extracts (ethanol, water and methanol) prepared from Eupatorium fortunei Turcz at concentrations of 500 and 200 µg/mL on the growth of Microcystisaeruginosain a 10-day experiment. By using optical density method, the ethanol extract at concentration of 500 µg/mL indicated the highest toxicity with the inhibition efficiency reaching % after 10 days which was significantly greater than those of the water, methanol extracts at the same concentration and that of CuSO4 at 5 µg/mL ( %, % and 81,7 %, respectively). In addition, the pH of the algal suspensions was fluctuated from to for the control and extract-treated samples. In contrast, the pH of the CuSO4-treated suspension decreased to - . These results proved that the E. fortunei Turcz ethanol extract had the best properties at 500 µg/mL in comparision with other .
