以铜绿微囊藻为试验材料,应用正交试验法,在培养温度(25℃)及接种量相同的情况下,研究光限制胁迫协同pH与氮磷比对铜绿微囊藻生长的影响.影响铜绿微囊藻生长的因素顺序为:pH光限制胁迫天数氮磷比,pH为铜绿微囊藻生长的显著性影响因素(F=63.111 5),且在pH 10.5、氮磷比15∶1及光限制胁迫5 d的条件下正常光照培养4 d后藻细胞数量最大.

The synergistic effects of pH value , ratio of N/P, and light limitation on the growth of Microcystis aeruginosa were investigated by orthogonal tests .Results of orthogonal test for the selective preference of the growth condition for M .aeruginosa showed that pH can significantly affect the growth of M .aeruginosa, and the optimal factor combination is pH 10.5, stress of 5 days and 15/1 for N/P.Under 25℃, the order of effect on the M .aeruginosa is pH>stress of light limitation >N/P, detected after cultured under normal light intensity for 4 days.

对分离自山东黄岛和江苏太湖两处富营养化池塘中的2株溶藻细菌的培养条件进行了优化,探究了2菌株对铜绿微囊藻生长的抑制作用。实验结果显示,2菌株可通过凝聚藻体细胞、裂解微藻细胞体以及胞外分泌活性物质产生生物降解作用,对铜绿微囊藻产生杀灭效果,且分泌的胞外活性物质对铜绿微囊藻的杀灭作用具有特异性。

The culture conditions of two strains of algicidal bacteria, which isolated from two eutrophic ponds in Shandong Huangdao and Jiangsu Taihu, are optimized. The inhibitory effect of the two strains on the growth of Mi-crocystis aeruginosa are explored. The experimental results show that the two strains can produce biological degrada-tion by coagulation algae cells, cleavage of microalgae cells and extracellular secretion of active substances to kill the algae cells. Besides, the killing effect of extracellular substances of two strains on Microcystis aeruginosa are specificity.

为认知星肋小环藻(硅藻)春季活动、滇池铜绿微囊藻(蓝藻)春夏大规模暴发的活动规律,通过确定生长温区后进行变温实验,分析低温对2种实验藻的生长影响,其结果为:小环藻的生长温度为9.5~15.0℃,微囊藻生长温度为15.0~31.0℃,生长高温将抑制2种藻的生长;15.5℃以上、9.0℃以下时小环藻停止生长,31.0℃以上、15.0℃以下时微囊藻停止生长;在15.5~17.5℃停止生长后用7.0~9.0℃处理一天后放回生长温度培养,小环藻恢复生长,在31.0~33.0℃停止生长后用7.0~14.0℃处理一天后放回生长温度培养,微囊藻恢复生长,表明特定低温可使处于高温休眠的藻恢复生长,即低温具有解除高温休眠的作用;诱导低温7.5~9.5℃、10.0~14.0℃时,星肋小环藻、铜绿微囊藻的生长与低温诱导强度反相关,与诱导时间正相关;低温可解除高温休眠作用诱导藻生长,同样,高温也可解除藻的低温诱导作用。分析认为:星肋小环藻、铜绿微囊藻的低温诱导作用与植物春化作用一致,因此实验藻具有春化作用,其年活动规律为:经冬季低温诱导,处于休眠的实验藻春季恢复生长,夏季生长高温抑制铜绿微囊藻生长,秋季无诱导低温过程,铜绿微囊藻华可发生但不如春夏。

To study the activities of the Cyclotella asterocostata in spring and Microcystis aeruginosa in Dianchi Lake in spring and summer, on the basis of the experiment to determine the growth temperature, Analyses the low temperature impact on two experimental algae growth. The results show that:the Cyclotella asterocostata growth temperature was 9.5~15.0 ℃, the Microcystis aeruginosa growth temperature was 15.0~31.0 ℃, growth high temperature would restrain the growth of the two kinds of experimental algae. The Cyclotella asterocostata stopped growing when the temperature was more than 15.5 ℃, 9.0 ℃ below, it was the same to Microcystis aeruginosa(more than 31.0 ℃, 15.0 ℃ below). The stop growing Cyclotella asterocostata will recovery growth after treated with 7.0~9.0 ℃ for a day and back on the growth temperature, it was the same to Microcystis aeruginosa which was treated with 7.0~14.0 ℃. This showed that specific low temperature could make experimental algae recovery gr

以铜绿微囊藻(Microsystis aeruginosa)作为生物模型,通过测定藻细胞氧化损伤程度与藻细胞内外藻毒素LR(microcystin-LR,MC-LR)的含量,研究除草剂禾草灵的生态毒性。结果表明,禾草灵在实验室处理质量浓度1,2,5mg/L下,能诱导铜绿微囊藻细胞活性氧(reactive oxygen species,ROS)的产生,引起细胞脂质过氧化水平丙二醛(malondialdehyde,MDA)的提高和超氧化物歧化酶(superoxide dismutase,SOD)的活性增强。说明禾草灵对铜绿微囊藻产生了氧化胁迫。5mg/L禾草灵使铜绿微囊藻释放到细胞外的微囊藻毒素MC-LR显著增加,为空白对照的68.5,2.11,2.50,123.67倍(第2,3,4,5天);细胞内MC-LR含量与空白对照相比有一定的降低,为空白对照的0.34,0.82,2.76,0.11倍(第2,3,4,5天)。说明禾草灵在一定质量浓度下能对铜绿微囊藻产生氧化胁迫,引起藻细胞脂质过氧化,从而引起细胞膜损伤,导致微囊藻毒素MC-LR更多的释放到水体中,对水环境造成一定的影响。实验结果可对禾草灵的环境安全评价提供一定的参考。

Summary Diclofop-methyl is a postemergence herbicide introduced in the 1 960s.It is widely used on wheat, barley,and golf courses (turf) all over the world.Residues of diclofop-methyl may pollute the water system and affect the physiological processes in cyanobacteria.Causative cyanobacteria can often cause serious environmental, aesthetic,and economic problems;besides,it can produce microcystins(MCs)which are toxic to domestic livestock and wildlife.Certain environmental factors such as pH,temperature,and the amount of nitrogen and phosphorus in the water have been found to affect the production of MCs.But other factors,such as the concentration of environmental pollutants including pesticide residues which may be prevalent in aquatic ecosystems,have not been studied in sufficient detail. In the current study,oxidative damage and toxin release from Microsystis aeruginosa caused by diclofop-methyl were investigated.Diclofop-methyl was proposed to induce oxidative stress in susceptible

对水芹、美人蕉、黄菖蒲、菹草4种水生植物对铜绿微囊藻的化感特征进行了研究。不同的植物组织器官及不同的植物处理方式下，抑藻效果不同，最具抑藻潜力的植物为黄菖蒲和美人蕉。经黄菖蒲和美人蕉种植水培养5d后，铜绿微囊藻的抑制率达70.12％～77.25％。质量分数为0.53％的黄菖蒲叶提取物，经11 d的培养后，对铜绿微囊藻的抑制率为65.30％。抑藻机理可能在于化感物质的胁迫使微囊藻细胞内活性氧自由基过量堆积，进而引起对藻细胞的伤害和影响藻类正常的光合作用。SOD酶活性与藻的比增长率均呈现较好的负相关关系。

The allelopathic effects of four aquatic macrophytes (Iris pseudacorus,Canna indica,OenantheJavani-ca,and Potamogeton)on the growth of Microcystis aeruginosa were investigated.The allelopathic effects were dif-ferent by different organs and various pretreatment.Iris pseudacorus and Canna indica were found to have the most potentialities of controlling algae.The water after culturing Iris pseudacorus and Canna indica were used to culture algae.The inhibition rate of algae could reach 70.12% to 77.25% five days later.The liquid extracted from the leaves of Iris pseudacorus with 0.53 percentage of mass fraction was applied to culture algae for 1 1 days.The inhibi-tion rate was 65.30%.The allelopathic mechanism could be explained by the stress fromthe allelopathic materials that damaged and hindered the photosynthesis of algae through improving the accumulation of active oxygen radicals in the cells of algae.In addition,the activity of superoxide dismutase (SOD)showed a good nega