【作者】 林少君；

【导师】 韩博平； 王朝晖；

【作者基本信息】 暨南大学 ， 环境科学， 2005， 硕士

【摘要】 为了了解微囊藻毒素在广东省典型供水水库以及湖泊中的分布,于2003年的7、9和12月对广东省分布于6个流域的12个典型供水水库以及4个城市景观湖泊进行采样,用高效液相色谱法（HPLC）分析了微囊藻毒素MC-LR和MC-RR的含量,并用酶联免疫法（ELISA）测定总微囊藻毒素含量;2004年,对新丰江、鹤地和汤溪等7个重点水库和星湖进行加密调查,用ELISA测定总微囊藻毒素含量。广东省水库微囊藻毒素类型以MC-RR为主,其含量明显高于MC-LR。整体上2004年总微囊藻毒素浓度高于2003年,但没有超出国家饮用水源标准。汤溪水库总微囊藻毒素最高值为0.92μtg·L^-1,鹤地水库、深圳水库和契爷石水库的最高检测值在0.40-0.61μg·^-1之间,不能排除在这几个水库中潜在慢性促肿瘤的风险。 对分离自深圳水库的产毒水华微囊藻（Microcystis flos-aquae）进行了生理生态和产毒特性研究。结果发现,水华微囊藻生长的饱和光强为250μE m^-2s^-1。光强≥170μEm^-2s^-1时培养液中毒素浓度维持在较高水平,而光强较低时(50-100μE m^-2s^-1)细胞毒素含量较高(0.56-0.41 pg·cell^-1)。在磷和氮分别固定的条件下(磷为7.13 mg·L^-1;氮为41.20mg·L^-1),当氮磷原子比达到16:1时,微囊藻的生长速率达到最大。氮对培养液中毒素浓度以及单位叶绿素a毒素质量的影响要小于磷,当磷浓度低于5.76mg·L^-1时培养液中毒素浓度随磷浓度升高而升高。氮磷和生长曲线实验中单位细胞毒素含量受细胞生长速率的影响,与细胞生长速率呈负相关。在光照实验和氮磷实验中毒素和叶绿素a总体上具有较好的相关性。 结合广东省多变化的气候条件,对光照、温度和氮磷浓度突然变化对微囊藻生长和产毒的影响进行研究。结果认为,光强和温度的突然增加能促进微囊藻细胞的分裂,是微囊藻水华在短期内形成的主要调控因子。光强的突然变化或氮磷浓度的突然下降会导致细胞毒素含量相对增加,而温度的突然变化或氮磷浓度的突然升高则导致单位细胞毒素含量下降。随着藻细胞对变化后温度的适应,低温下单位叶绿素a毒素质量高于高温条件。更多还原

【Abstract】 To study the distribution of microcystin in fresh waters especially water supply reservoirs in Guangdong Province, water samples were collected in 12 reservoirs and 4 urban lakes in July, September and December in 2003. In 2004, 7 reservoirs and one lake （Xinghu Lake） were sampled biomonthly for analysis of microcystin dynamic. The microcystin concentration was detected by HPLC （High-Performance Liquid Chromatograph） and ELISA （Enzyme-Linked Immunosorbent Assay） . In most of the sampled water bodies, the microcystin was dominated by MC-RR. Though the microcystin concentrations in 2004 increase a lot in most reservoirs, the MC levels were below the critical value for drinking water.A series of experiments were designed for physiological and ecological study and toxin-produced characteristics of a stain of Microcystis flos-aquae, which was separated from the Shenzhen Reservoir. M. flos-aquae was cultured under photosynthetically active radiation（PAR） intensity between 10 and 450 umol of photons m^-2·s^-1. The growth rate was highest when the light intensity was 250μmol of photons m^-2·s^-1. The microcystin concentration maintained in higher level while the light intensities were more than 170 umol of photons m^-2·s^-1 while the cellular microcystin were high when the light intensities between 50 and 100μmol of photons m^-2·s^-1. The growth rate was highest when N:P ratio was near 16. Phosphorus had more effect than nitrogen on MC production. When the phosphorus concentration was below 5.76 mg L^-1, the MC concentration increased with the phosphorus concentration. The growth rate negatively correlated to the cellular microcystin content. The highly significant relationship between the microcystin content and the chlorophyll-a content suggested that the ligh intensities may be the primary factor to affect the synthesizing of microcystin.A group of experiments were carried to study the effects of the rapid change of the environmental factors including temperature, light intensity and nutrients on the growth and toxin production of M. flos-aquae. The results showed that the rapid increase of light intensity and temperature can stimulated cell growth. The rapid change of light intensity or the rapid decrease of nutrient would result in the increase of the cellular MC while therapid change of temperature or the rapid increase of nutrient would result in the decrease of the cellular MC. Although the rapid change of temperature would reduce the synthesizing of microcystin, the ratio of microcystin to chlorophyll-a was higher in low temperature than that in high temperature.更多还原