Objective To isolate and characterize indigenous algicidal bacteria and their algae-lysing compounds active against Microcystis aeruginosa, strains TH1, TH2, and FACHB 905. Methods The bacteria were identified using t...Objective To isolate and characterize indigenous algicidal bacteria and their algae-lysing compounds active against Microcystis aeruginosa, strains TH1, TH2, and FACHB 905. Methods The bacteria were identified using the Biolog automated microbial identification system and 16S rDNA sequence analysis. The algae-lysing compounds were isolated and purified by silica gel column chromatography and reverse-phase high performance liquid chromatography. Their structures were confirmed by Nuclear Magnetic Resonance （NMR） and Fourier Transform infrared （FT-IR） spectroscopy. Algae-lysing activity was observed using microscopy. Results The algae-lysing bacterium LTH-2 isolated from Lake Taihu was identified as Serratia marcescens. Strain LTH-2 secreted a red pigment identified as prodigiosin （C20H25N30）, which showed strong lytic activity with algal strains M. aeruginoso TH1, TH2, and FACHB 905 in a concentration-dependent manner. The 50% inhibitory concentration （ICs0） of prodigiosin with the algal strains was 4.8 （±0.4）×10^-2 μg/mL, 8.9 （±1.1）×10^-2μg/mL, and 1.7 （±0.1）×10^-1 μg/mL in 24 h, respectively. Conclusion The bacterium LTH-2 and its pigment related to damage of cell membranes. The bacterium for regulating blooms of harmful M. aeruginosa. had strong Microcystis-lysing activity probably LTH-2 and its red pigment are potentially useful展开更多
Qingdao waters,including both the semi-enclosed Jiaozhou Bay(JB) and the adjacent water out of JB(OJB),have been the areas that are most frequently affected by harmful algal blooms(HABs) in the western Yellow Sea(west...Qingdao waters,including both the semi-enclosed Jiaozhou Bay(JB) and the adjacent water out of JB(OJB),have been the areas that are most frequently affected by harmful algal blooms(HABs) in the western Yellow Sea(west of 124°E).In this research,HAB occurrences in Qingdao waters from 1990 to 2009 were investigated using spatial tools in geographic information system(GIS) and are discussed in terms of their connection to temporal variation.Additionally,the effects of each HAB occurrence were further evaluated using a simple model.The calculated results were then visualized using a GIS software to indicate the effects of HABs in Qingdao waters during the entire period.As a result,the OJB was proven to be responsible for the frequent HAB occurrences in Qingdao waters after 2000,although JB was traditionally believed to be the principle source of HAB occurrences in Qingdao waters.In addition,increasing nitrogen and N/P structure imbalance were essential for increasing HAB occurrences in Qingdao waters throughout the entire period,especially for the recent HAB occurrences in the OJB.The results of this research would improve the current understanding on HAB occurrences in Qingdao waters,which would benefit HAB monitoring and the implementation of a control strategy in China as well.展开更多
Over the past few years, harmful algal blooms （HABs）, such as red tides, have been frequently observed in coastal zones worldwide. The natural allelopathic interactions among macroalgae and red tide microalgae can a...Over the past few years, harmful algal blooms （HABs）, such as red tides, have been frequently observed in coastal zones worldwide. The natural allelopathic interactions among macroalgae and red tide microalgae can alter the structure and succession of aquatic ecosystems. We investigated the influence of four environmental factors （temperature, salinity, light, and pH） on the allelopathic effects of the macroalgae Corallina pilulifera on red-tide forming Heterosigma akashiwo under laboratory conditions. Each of the factors had four levels： temperature （15, 20, 25, and 30℃）, salinity （10, 20, 30, and 40）, light （20, 100, 200 and 400 gmol/（m2.s））, and pH （5.5, 7, 8.5, and 10. Two-factor experiments were designed for each two environmental factors, with six combination treatments （temperature-salinity, temperature-light, temperature-pH, salinity-light, salinity-pH, and light-pH）. Results showed that the allelopathic effect was significantly influenced by temperature, salinity, light, and pH. As single factors, the low temperature （15 ℃）, low salinity （10）, high-intensity light （400umol/（m2.s））, and high pH （10） treatments substantially enhanced the allelopathic effect. The strongest allelopathic effect of C. pilulifera on H. akashiwo was observed under the following treatments： 15℃ and salinity of 40, 25℃ and pH 10, 25℃ with medium- to high-intensity light at 200-400 umol/（m2.s）, 400umol/（m2.s） and salinity of 10, 400 gmol/（m2·s） and pH 10, and pH 10 with a salinity of 40.展开更多
Prorocentrum donghaiense is a dinoflagellate that is widely distributed in the East China Sea and has become increasingly involved in Harmful Algal Blooms (HABs). Therefore, it is necessary to study this dinoflagellat...Prorocentrum donghaiense is a dinoflagellate that is widely distributed in the East China Sea and has become increasingly involved in Harmful Algal Blooms (HABs). Therefore, it is necessary to study this dinoflagellate to monitor HABs. In this study, 13 pairs of primers specific to P. donghaiense (within its internal transcribed spacer (ITS) regions) were designed for SYBR Green I real-time PCR. As the SYBR Green I real-time PCR could not identify P. donghaiense in a specific manner, a Taqman real-time PCR method was developed by designing a set of specific primers and a Taqman probe. A 10-fold serial dilution of recombinant plasmid containing ITS regions of P. donghaiense was prepared as standard samples and the standard curve was established. Additionally, we quantified the genomic DNA in P. donghaiense cells and utilized this DNA to prepare another 10-fold serial dilution of standard sample and accordingly set up the standard curve. The mathematic correlation between the cell number and its corresponding plasmid copy number was also established. In order to test the efficiency of the real-time PCR method, laboratory samples and P. donghaiense HAB field samples were employed for identification and quantitative analysis. As to laboratory samples, as few as 102 cells of P. donghaiense could be quantified precisely utilizing both centrifugation and filtration techniques. The quantification results from field samples by real-time PCR were highly similar to those by light microscopy. In conclusion, the real-time PCR could be applied to identify and quantify P. donghaiense in HABs.展开更多
基金supported by the National Science and Technology Major Project (2012ZX07101-005)the National Natural Science Foundation of China (30972440)Jiangsu Province Postgraduate Innovation Project (CX10B-087Z)
文摘Objective To isolate and characterize indigenous algicidal bacteria and their algae-lysing compounds active against Microcystis aeruginosa, strains TH1, TH2, and FACHB 905. Methods The bacteria were identified using the Biolog automated microbial identification system and 16S rDNA sequence analysis. The algae-lysing compounds were isolated and purified by silica gel column chromatography and reverse-phase high performance liquid chromatography. Their structures were confirmed by Nuclear Magnetic Resonance （NMR） and Fourier Transform infrared （FT-IR） spectroscopy. Algae-lysing activity was observed using microscopy. Results The algae-lysing bacterium LTH-2 isolated from Lake Taihu was identified as Serratia marcescens. Strain LTH-2 secreted a red pigment identified as prodigiosin （C20H25N30）, which showed strong lytic activity with algal strains M. aeruginoso TH1, TH2, and FACHB 905 in a concentration-dependent manner. The 50% inhibitory concentration （ICs0） of prodigiosin with the algal strains was 4.8 （±0.4）×10^-2 μg/mL, 8.9 （±1.1）×10^-2μg/mL, and 1.7 （±0.1）×10^-1 μg/mL in 24 h, respectively. Conclusion The bacterium LTH-2 and its pigment related to damage of cell membranes. The bacterium for regulating blooms of harmful M. aeruginosa. had strong Microcystis-lysing activity probably LTH-2 and its red pigment are potentially useful
基金Supported by the National Natural Science Foundation of China(NSFC)-Shandong Joint Fund for Marine Science Research Centers(No.U1406403)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA11020302)+1 种基金the National Natural Science Foundation of China for Young Scholars(No.41506135)the National Nature Science Foundation of China for Creative Group Research(No.41121064)
文摘Qingdao waters,including both the semi-enclosed Jiaozhou Bay(JB) and the adjacent water out of JB(OJB),have been the areas that are most frequently affected by harmful algal blooms(HABs) in the western Yellow Sea(west of 124°E).In this research,HAB occurrences in Qingdao waters from 1990 to 2009 were investigated using spatial tools in geographic information system(GIS) and are discussed in terms of their connection to temporal variation.Additionally,the effects of each HAB occurrence were further evaluated using a simple model.The calculated results were then visualized using a GIS software to indicate the effects of HABs in Qingdao waters during the entire period.As a result,the OJB was proven to be responsible for the frequent HAB occurrences in Qingdao waters after 2000,although JB was traditionally believed to be the principle source of HAB occurrences in Qingdao waters.In addition,increasing nitrogen and N/P structure imbalance were essential for increasing HAB occurrences in Qingdao waters throughout the entire period,especially for the recent HAB occurrences in the OJB.The results of this research would improve the current understanding on HAB occurrences in Qingdao waters,which would benefit HAB monitoring and the implementation of a control strategy in China as well.
基金Supported by the National Natural Science Foundation of China(No.31200400)
文摘Over the past few years, harmful algal blooms （HABs）, such as red tides, have been frequently observed in coastal zones worldwide. The natural allelopathic interactions among macroalgae and red tide microalgae can alter the structure and succession of aquatic ecosystems. We investigated the influence of four environmental factors （temperature, salinity, light, and pH） on the allelopathic effects of the macroalgae Corallina pilulifera on red-tide forming Heterosigma akashiwo under laboratory conditions. Each of the factors had four levels： temperature （15, 20, 25, and 30℃）, salinity （10, 20, 30, and 40）, light （20, 100, 200 and 400 gmol/（m2.s））, and pH （5.5, 7, 8.5, and 10. Two-factor experiments were designed for each two environmental factors, with six combination treatments （temperature-salinity, temperature-light, temperature-pH, salinity-light, salinity-pH, and light-pH）. Results showed that the allelopathic effect was significantly influenced by temperature, salinity, light, and pH. As single factors, the low temperature （15 ℃）, low salinity （10）, high-intensity light （400umol/（m2.s））, and high pH （10） treatments substantially enhanced the allelopathic effect. The strongest allelopathic effect of C. pilulifera on H. akashiwo was observed under the following treatments： 15℃ and salinity of 40, 25℃ and pH 10, 25℃ with medium- to high-intensity light at 200-400 umol/（m2.s）, 400umol/（m2.s） and salinity of 10, 400 gmol/（m2·s） and pH 10, and pH 10 with a salinity of 40.
基金supported by the National Basic Research Program of China (973 Program) (No.2011CB403602)the National High Technology Research and Development Program of China (863 Program) (No.2007AA09200111)the National Marine Public Welfare Research Project (201205031-02)
文摘Prorocentrum donghaiense is a dinoflagellate that is widely distributed in the East China Sea and has become increasingly involved in Harmful Algal Blooms (HABs). Therefore, it is necessary to study this dinoflagellate to monitor HABs. In this study, 13 pairs of primers specific to P. donghaiense (within its internal transcribed spacer (ITS) regions) were designed for SYBR Green I real-time PCR. As the SYBR Green I real-time PCR could not identify P. donghaiense in a specific manner, a Taqman real-time PCR method was developed by designing a set of specific primers and a Taqman probe. A 10-fold serial dilution of recombinant plasmid containing ITS regions of P. donghaiense was prepared as standard samples and the standard curve was established. Additionally, we quantified the genomic DNA in P. donghaiense cells and utilized this DNA to prepare another 10-fold serial dilution of standard sample and accordingly set up the standard curve. The mathematic correlation between the cell number and its corresponding plasmid copy number was also established. In order to test the efficiency of the real-time PCR method, laboratory samples and P. donghaiense HAB field samples were employed for identification and quantitative analysis. As to laboratory samples, as few as 102 cells of P. donghaiense could be quantified precisely utilizing both centrifugation and filtration techniques. The quantification results from field samples by real-time PCR were highly similar to those by light microscopy. In conclusion, the real-time PCR could be applied to identify and quantify P. donghaiense in HABs.
