Ghobrial M.G

Ghobrial M.G

National Institute of Oceanography and Fisheries, Egypt

Title: Bioactivity Effect of Two Macrophytes Extracts on Growth Performance of Two Bloom-Forming Cyanophytes


Professor of Aquatic Plants in Hydrobiology Lab. Marine Environment Division. National Institute Of Oceanography & Fisheries (NIOF) – Ministry Of Scientific Research, Arab Republic Of Egypt (ARE). Ph.D. in Botany, Faculty of Science, Alexandria University. Field of Interest Research activities on: the use of aquatic plants and algae for phytoremediation. Allelopathic potential of aquatic plants for use as algicidal, and bactericidal agents. Investigations on the emergent macrophytes used for treatment of groundwater aromatic hydrocarbon contaminants in constructed wetlands. Climate changes impact on water environmental resources. Aquatic plants (marine and freshwater) use as antibacterial and antifungal agents against fish pathogens. Combat of algal blooming. Plants biotechnology.. Recently, uses aquatic macro and microalgae nanoparticles for antibacterial and antialgal bloom forming researches


Aqueous extracts of two freshwater macrophytes; Potamogeton pectinatus and Ceratophyllum demersum with 50% and 100% each with acetone and ethanol solvents were tested on growth performance of two bloom-forming cyanophytes, Microcystis aeruginosa and Oscillatoria tenuis. The results revealed no significant difference between the overall total average growth performance at treatment with 50% and 100% Ceratophyllum acetone extracts expressed by optical density (OD) as well as chlorophyll a (chl a). They showed, both, stimulation of Microcystis aeruginosa growth. The highest growth increase in 100 µL/100ml treatment with 50% acetone extract had percentage rate R, 94.66. On the contrary, treatment with ethanol extract recorded the highest inhibitory effect, thus in 1.5 µL/100ml treatment with 50% Ceratophyllum ethanol extract R recorded -87.54, sustaining LC50 value 1.12 µl/100 ml. The highest stimulating effect in 105µL/100 ml treatment with 50% Ceratophyllum acetone extracts against Oscillatoria tenuis was; R, 169.4. The highest inhibition in 1500 µL/100ml treatment with 50% Ceratophyllum ethanol extracts against Oscillatoria tenuis was ;R-74.32, with LC50 0.830 µl/100 ml. While, the highest inhibition by 50% and 100% Potamogeton acetone or ethanol extracts against M. aeruginosa were in 80 and 70 µL/100 ml treatments with R, -99.80 for both. There are significant differences between the overall averages for each solvent, both of 50% and 100% Potamogeton extracts against Oscillatoria as estimated by OD or chl a. The highest inhibitory effect for Potamogeton against Oscillatoria were in 103, 800, 200 and 180 µL/100ml using 50%, 100%, either acetone or ethanol extracts treatments, were R, -66.56, -73.24, -85.95 and -85.95, in return for LC50 932, 590, 129.50 and 101.428 µl/100 ml, respectively.