Harmful cyanobacterial blooms, especially Microcystis blooms, occur worldwide and draw widespread attention. The dynamics of microcystin-producing Microcystis and competition between microcystin-producing Microcystis ...Harmful cyanobacterial blooms, especially Microcystis blooms, occur worldwide and draw widespread attention. The dynamics of microcystin-producing Microcystis and competition between microcystin-producing Microcystis and non-microcystin-producing Microcystis are key to predicting and treating Microcystis blooms. Multiplex qPCR is a useful tool to assess such issues. In this study, we developed multiplex qPCR methods with newly-designed probes and primers for the microcystin-synthesis related genes mcyA and mcyE. We used seven toxic Microcystis strains and four non-toxic Microcystis strains to compare the differences in the ratios of toxic and non-toxic Microcystis in mixed cultures, which were calculated using abundances of the genes mcyA, mcyB, mcyD, mcy E and phycocyanin( PC). We also compared traditional cell counting and multiplex qPCR. Hierarchical clustering and principal component analysis indicated that mcyD was the most suitable mcy gene for quantification in laboratory experiments. mcyB abundances were always higher; we suggest that the amount of toxic Microcystis measured using mcyB might overestimate the actual percentages.展开更多
Water eutrophication has become a worldwide environmental problem in recent years.Once a water body is eutrophicated,it will lose its primary functions and subsequently influence sustainable development of society and...Water eutrophication has become a worldwide environmental problem in recent years.Once a water body is eutrophicated,it will lose its primary functions and subsequently influence sustainable development of society and economy.Therefore,analysis of eutrophication becomes one of the most essential issues at present.With the ability to deal with vague and uncertain information,and express knowledge in a rule form,the rough set theory(RST) has been widely applied in diverse domains.The advantage of RST is that it can compress the rule and remove needless features by reduction inference rule.By this way,the rule gets effectively simplified and inference efficiency gets improved.However,if data amount is relatively big,it could be a process with large calculated amount to search rules by looking up tables.Petri nets(PNs) possesses so powerful parallel reasoning ability that inference result could be obtained rapidly merely by simple matrix manipulation with no need for searching rules by looking up tables.In this work,an integrated RPN model combining RST with PN was used to analyze relations between degrees of water eutrophication level and influence factors in the Pengxi River of Three Gorges Reservoir.It was shown that the RPN model could analyze water eutrophicaion accurately and quickly,and yield decision rules for the decision-makers at water purification plants of the water quality and assist them in making more cost-effective decisions.展开更多
Microcystis blooms are an environmental and ecological concern that has received a serious attention. Hydrogen peroxide(H_2O_2) is an environment-friendly cyanocide that is commonly used to control Microcystis blooms....Microcystis blooms are an environmental and ecological concern that has received a serious attention. Hydrogen peroxide(H_2O_2) is an environment-friendly cyanocide that is commonly used to control Microcystis blooms. While the ecological safety of H_2O_2 has been previously studied, its influence on bacterioplankton has not been investigated to date. In this study, we used mesocosm experiments to determine the influence of H_2O_2 on the dynamic changes of the community structure of bacterioplankton. By using deep-sequencing and metagenomics strategy we determined the community structures of phytoplankton and bacterioplankton assemblages that were dominated by M icrocystis at a highly eutrophic Dianchi Lake, China. The results showed that M icrocystis was more sensitive to H_2O_2 than other eukaryotic algae. More interestingly, application of H_2O_2 changed the community structure of bacterioplankton, evidenced by the emergence of F irmicutes as the dominant species in place of B acteroidetes and Proteobacteria. The H_2O_2 treatment resulted in the community of bacterioplankton that was primarily dominated by E xiguobacterium and Planomicrobium. Our results show that the abundance changed and the bacterioplankton diversity did not recover even after the concentration of H_2O_2 reached to the background level. Thus, the response of bacterioplankton must be considered when assessing the ecological risks of using H_2O_2 to control Microcystis blooms, because bacterioplankton is the key player that forms the basis of food web of aquatic environment.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.31370418,41561144008)the Jiangxi Water Science and Technology Fund(No.KT201602)the State Key Laboratory of Freshwater Ecology and Biotechnology(No.2016FBZ07)
文摘Harmful cyanobacterial blooms, especially Microcystis blooms, occur worldwide and draw widespread attention. The dynamics of microcystin-producing Microcystis and competition between microcystin-producing Microcystis and non-microcystin-producing Microcystis are key to predicting and treating Microcystis blooms. Multiplex qPCR is a useful tool to assess such issues. In this study, we developed multiplex qPCR methods with newly-designed probes and primers for the microcystin-synthesis related genes mcyA and mcyE. We used seven toxic Microcystis strains and four non-toxic Microcystis strains to compare the differences in the ratios of toxic and non-toxic Microcystis in mixed cultures, which were calculated using abundances of the genes mcyA, mcyB, mcyD, mcy E and phycocyanin( PC). We also compared traditional cell counting and multiplex qPCR. Hierarchical clustering and principal component analysis indicated that mcyD was the most suitable mcy gene for quantification in laboratory experiments. mcyB abundances were always higher; we suggest that the amount of toxic Microcystis measured using mcyB might overestimate the actual percentages.
基金Project(2014ZX07104-006)supported by the National Scientific and Technological Major Project of China
文摘Water eutrophication has become a worldwide environmental problem in recent years.Once a water body is eutrophicated,it will lose its primary functions and subsequently influence sustainable development of society and economy.Therefore,analysis of eutrophication becomes one of the most essential issues at present.With the ability to deal with vague and uncertain information,and express knowledge in a rule form,the rough set theory(RST) has been widely applied in diverse domains.The advantage of RST is that it can compress the rule and remove needless features by reduction inference rule.By this way,the rule gets effectively simplified and inference efficiency gets improved.However,if data amount is relatively big,it could be a process with large calculated amount to search rules by looking up tables.Petri nets(PNs) possesses so powerful parallel reasoning ability that inference result could be obtained rapidly merely by simple matrix manipulation with no need for searching rules by looking up tables.In this work,an integrated RPN model combining RST with PN was used to analyze relations between degrees of water eutrophication level and influence factors in the Pengxi River of Three Gorges Reservoir.It was shown that the RPN model could analyze water eutrophicaion accurately and quickly,and yield decision rules for the decision-makers at water purification plants of the water quality and assist them in making more cost-effective decisions.
基金Supported by the Major Science and Technology Program for Water Pollution Control and Treatment(No.2013ZX07102005)the National Natural Science Foundation of China(No.41561144008)the State Key Laboratory of Freshwater Ecology and Biotechnology(No.2016FBZ07)
文摘Microcystis blooms are an environmental and ecological concern that has received a serious attention. Hydrogen peroxide(H_2O_2) is an environment-friendly cyanocide that is commonly used to control Microcystis blooms. While the ecological safety of H_2O_2 has been previously studied, its influence on bacterioplankton has not been investigated to date. In this study, we used mesocosm experiments to determine the influence of H_2O_2 on the dynamic changes of the community structure of bacterioplankton. By using deep-sequencing and metagenomics strategy we determined the community structures of phytoplankton and bacterioplankton assemblages that were dominated by M icrocystis at a highly eutrophic Dianchi Lake, China. The results showed that M icrocystis was more sensitive to H_2O_2 than other eukaryotic algae. More interestingly, application of H_2O_2 changed the community structure of bacterioplankton, evidenced by the emergence of F irmicutes as the dominant species in place of B acteroidetes and Proteobacteria. The H_2O_2 treatment resulted in the community of bacterioplankton that was primarily dominated by E xiguobacterium and Planomicrobium. Our results show that the abundance changed and the bacterioplankton diversity did not recover even after the concentration of H_2O_2 reached to the background level. Thus, the response of bacterioplankton must be considered when assessing the ecological risks of using H_2O_2 to control Microcystis blooms, because bacterioplankton is the key player that forms the basis of food web of aquatic environment.
