Summary of doctoral thesis in Environmental engineering: Inhibitory effect of Eupatorium fortunei Turcz. extracts on the growth of a toxic cyanobacterial species Microcystis aeruginosa Kutzing in fresh waterbodies

Develop the process of producing crude extracts, fractions and pure chemical compounds isolated from E. fortunei; tudy of inhibitory effect of the crude ethanol extracts from E. fortunei on the growth of M.aeruginosa and evaluating their ecological safety to non-target aquatic organisms.
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Summary of doctoral thesis in Environmental engineering: Inhibitory effect of Eupatorium fortunei Turcz. extracts on the growth of a toxic cyanobacterial species Microcystis aeruginosa Kutzing in fresh waterbodies MINISTRY OF EDUCATION AND VIETNAM ACADEMY OF SCIENCE TRAINING AND TECHNOLOGY GRADUATE UNIVERSITY OF SCIENCE AND TECHNOLOGY ********************** PHAM THANH NGA INHIBITORY EFFECT OF EUPATORIUM FORTUNEI TURCZ. EXTRACTS ON THE GROWTH OF A TOXIC CYANOBACTERIAL SPECIES Microcystis aeruginosa IN FRESH WATERBODIES Major: Environmental Engineering Code: 9.52.03.20 SUMMARY OF DOCTORAL THESIS IN ENVIRONMENTAL ENGINEERING Hanoi - 2019 The doctoral thesis was completed at Institute of Environmental Technology (IET), Graduate University of Science and Technology, Vietnam Academy of Science and Technology Supervisors: Prof. Dr. Dang Dinh Kim Dr. Le Thi Phuong Quynh Reviewer 1. Reviewer 2. Reviewer 3. This doctoral thesis will be defended at Graduate University of Science and Technology, Vietnam Academy of Science and Technology at …… on …… 2019 This doctoral thesis can be found at: Library of the Graduate University of Science and Technology, VAST. 1 INTRODUCTION 1. NECESSITY OF DOCTORAL THESIS Eutrophication is a widespread problem in aquatic ecosystems around the world due to sewage and surface run-off. It significantly affects water quality and induces off-flavor problem. Moreover, cyanobacterial blooms usually break out along with release of cyanotoxins, which cause a series of adverse effects such as decreasing water quality and biodiversity, and illness in animals and humans. Among all sorts of microalgae, Microcystis aeruginosa, one of the most common representative species responsible for the water blooming, can produce hepatotoxins and neurotoxins which may lead to headache, fever, abdominal pain, nausea, vomiting and even cancer. Therefore, it is of great importance to inhibit the growth of cyanobacteria, especially M. aeruginosa in eutrophic waters. Basically, there are three short-term approaches to control harmful algal blooms such as chemical, physical and biological approaches. Chemical treatments can effectively and rapidly remove algal bloom. However, some algicidal chemicals can cause secondary pollution of aquatic environment or persistence in the environment and the inhibitory effects of most chemicals do not selectively target harmful cyanobacteria; leading to the collapse of aquatic ecosystems. Physical methods like mixing lake water using an air compressor, pressure devices or ultraviolet irradiation indicate less subsequent secondary pollution. However, the disadvantages of physical treatments of algal removal are energy intensive and tend to be low efficiency as well as injury to non-target species. In recent years, biological methods including using algicidal bacteria have received much more attention as alternatives to chemical agents. These approaches tend to be environmental friendly and promising methods for controlling toxic cyanobacteria. However, the efficiency of biological method is influenced by many biotic and abiotic factors in the environment. For these limitations of the above approaches, the discovery and use of natural compounds that feature selective toxicity towards phytoplankton communities and are nontoxic to other aquatic species, have been a significant advance in the management of aquatic ecosystems. Eupatorium fortunei Turcz, a species of Asteraceae, is a perennial herb used in folk medicine as a medicinal and has been demonstrated antibacterial activity in various scientific studies. In 2008, Nguyen Tien Dat and et al carried out the experiments of using plant extracts to inhibit the growth of M. aeruginosa. The results showed that the extract from E. fortunei indicated the highest inhibitory effect on the species. This conclusion was confirmed by the publication of Pham Thanh Nga in the following years. However, these are only preliminary studies investigating the using of the plant extract to control toxic cyanobacterial bloom. By wishing to inherit, develop previous research results and solve several reaserch questions related to the issue, author chose topic: “Inhibitory effect of Eupatorium fortunei Turcz. extracts on the growth of a toxic cyanobacterial species Microcystis aeruginosa Kützing in fresh waterbodies” 2. RESEARCH PROPOSE OF THE DOCTORAL THESIS Research to create effective plant extracts from E. fortunei to inhibit growth of Microcystis aeruginosa Kützing in the laboratory and outdoor larger scale. 3. TASKS OF THE DOCTORAL THESIS - Develop the process of producing crude extracts, fractions and pure chemical compounds isolated from E. fortunei - Study of inhibitory effect of the crude ethanol extracts from E. fortunei on the growth of M.aeruginosa and evaluating their ecological safety to non-target aquatic organisms. - Study of inhibitory effect of the fraction extracts from E. fortunei on the growth of M. aeruginosa and evaluating their ecological safety to non-target aquatic organisms. - Study of bioactive properties of chemical compounds isolated fr ...