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
Biography
Biography: Ghobrial M.G
Abstract
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.