In controlling eutrophication phenomenon, there were conventional methods which lead to negative effects to aquatic environment. This study was aimed to investigate the usage of synthesized thiourea compounds to inhib...In controlling eutrophication phenomenon, there were conventional methods which lead to negative effects to aquatic environment. This study was aimed to investigate the usage of synthesized thiourea compounds to inhibit the growth of Oscillatoria sp. in Kenyir lake, Terengganu, Malaysia. The inhibition effects of four eco-friendly alkoxyl thiourea derivatives compounds named as N-（（4-（decyloxy）phenyl）carbamothioyl）-4-methyl benzamide, N-（（4-（decyloxy）phenyl）carbamothioyl）-4-nitro benzamide, 4-chloro-N-（（4-（decyloxy）phenyl）carbamothioyl） benzamide and N-（（4-（decyloxy）phenyl）carbamothioyl） benzamide were examined onto the growth culture of Oscillatoria sp. These compounds were tested in 30 mL of Oscillatoria sp. cultures with different concentration of 16 μg·mL-1, 18 μg·mL-1, 20 μg·mL-1, 24 μg·mL-1 and 28 μg·mL-1respectively. The treatment flasks were supplied with an aerator for 24 hours under continuous illumination at 25 ℃. Chlorophyll-a concentration were extracted to calculate the inhibition percentage of each treatment. Overall, all these compounds showed inhibition effects towards the growth of Oscillatoria sp., with the highest inhibition of 37% by N-（（4-（decyloxy）phenyl）carbamothioyl）-4-methyl benzamide at the concentration of 18μg·mL-1. The methyl group that attach to the synthesized compound may contribute to the effectiveness of the compound which act as an algae inhibitor. However, extensive studies still need to be conducted in order to investigate the mechanism on how this compound reacts with Oscillatoria sp..展开更多
Shang Xun, Dai Jixun, Han Baoqin, Ru Binggen, Zhou Xianwan ( Marine Life Sciences College, Ocean University of Qingdao, Qingdao 266003 College of Life and Sciences, Peking University,Beijing 100871)
Spatial variations in phytoplankton community within a large mesotrophic reservoir （Miyun reservoir, North China） were investigated in relation to variations in physico-chemical properties, nutrient concentrations, ...Spatial variations in phytoplankton community within a large mesotrophic reservoir （Miyun reservoir, North China） were investigated in relation to variations in physico-chemical properties, nutrient concentrations, temperature and light conditions over a 5 month period in 2009. The dynamics of phytoplankton community was represented by the dominance of cyanobacteria through summer and fall, following with a short term dominance of chlorophyta in late fall, and a relatively high abundance of diatom in October; on the other hand, maximum phytoplankton biomass was recorded in the north shallow region of Miyun reservoir with a higher nutrients level. Particular attention was paid to the impacts of environmental conditions on the growth of two cyanobacteria genera, the toxin-producing Microcystis and the taste ＆ odor-producing Oscillatoria. Microcystis biomass was in general greatly affected by water temperature and mixing depth/local water depth ratio in this reservoir, while the Oscillatoria biomass in the surface and middle layers was greatly affected by total dissolved phosphorus, and that in the bottom layer was related with the Secchi depth/local water depth ratio. Abundant Oscillatoria biomass was observed only in late September when Microcystis biomass decreased and allowed sufficient light go through.展开更多
文摘In controlling eutrophication phenomenon, there were conventional methods which lead to negative effects to aquatic environment. This study was aimed to investigate the usage of synthesized thiourea compounds to inhibit the growth of Oscillatoria sp. in Kenyir lake, Terengganu, Malaysia. The inhibition effects of four eco-friendly alkoxyl thiourea derivatives compounds named as N-（（4-（decyloxy）phenyl）carbamothioyl）-4-methyl benzamide, N-（（4-（decyloxy）phenyl）carbamothioyl）-4-nitro benzamide, 4-chloro-N-（（4-（decyloxy）phenyl）carbamothioyl） benzamide and N-（（4-（decyloxy）phenyl）carbamothioyl） benzamide were examined onto the growth culture of Oscillatoria sp. These compounds were tested in 30 mL of Oscillatoria sp. cultures with different concentration of 16 μg·mL-1, 18 μg·mL-1, 20 μg·mL-1, 24 μg·mL-1 and 28 μg·mL-1respectively. The treatment flasks were supplied with an aerator for 24 hours under continuous illumination at 25 ℃. Chlorophyll-a concentration were extracted to calculate the inhibition percentage of each treatment. Overall, all these compounds showed inhibition effects towards the growth of Oscillatoria sp., with the highest inhibition of 37% by N-（（4-（decyloxy）phenyl）carbamothioyl）-4-methyl benzamide at the concentration of 18μg·mL-1. The methyl group that attach to the synthesized compound may contribute to the effectiveness of the compound which act as an algae inhibitor. However, extensive studies still need to be conducted in order to investigate the mechanism on how this compound reacts with Oscillatoria sp..
文摘Shang Xun, Dai Jixun, Han Baoqin, Ru Binggen, Zhou Xianwan ( Marine Life Sciences College, Ocean University of Qingdao, Qingdao 266003 College of Life and Sciences, Peking University,Beijing 100871)
基金supported by the National Natural Science Foundation of China (No. 50938007)
文摘Spatial variations in phytoplankton community within a large mesotrophic reservoir （Miyun reservoir, North China） were investigated in relation to variations in physico-chemical properties, nutrient concentrations, temperature and light conditions over a 5 month period in 2009. The dynamics of phytoplankton community was represented by the dominance of cyanobacteria through summer and fall, following with a short term dominance of chlorophyta in late fall, and a relatively high abundance of diatom in October; on the other hand, maximum phytoplankton biomass was recorded in the north shallow region of Miyun reservoir with a higher nutrients level. Particular attention was paid to the impacts of environmental conditions on the growth of two cyanobacteria genera, the toxin-producing Microcystis and the taste ＆ odor-producing Oscillatoria. Microcystis biomass was in general greatly affected by water temperature and mixing depth/local water depth ratio in this reservoir, while the Oscillatoria biomass in the surface and middle layers was greatly affected by total dissolved phosphorus, and that in the bottom layer was related with the Secchi depth/local water depth ratio. Abundant Oscillatoria biomass was observed only in late September when Microcystis biomass decreased and allowed sufficient light go through.
