【作者】 谭啸；

【导师】 徐旭士； 孔繁翔；

【作者基本信息】 南京师范大学 ， 微生物学， 2006， 硕士

【摘要】 湖泊富营养化是我国许多地方存在的严重水环境问题。伴随着湖泊富营养化而出现的藻类水华对饮用水安全、水产养殖以及湖泊环境造成了巨大危害。在蓝藻水华出现时微囊藻(Microcystis)往往成为水华优势种已经引起了大家的广泛关注。本研究根据水华形成的四阶段理论，着重在复苏、生长以及聚集成群体三阶段对微囊藻的生物学特性进行了初步地探讨，得出了以下结论： (1)在复苏阶段通过对太湖蓝藻复苏进行原位的实验研究可知太湖底泥中蓝藻的复苏从三月到六月呈现波动性的增长，并在四月份达到最大量，这与水柱中蓝藻生物量的变化趋势一致。太湖水柱中蓝藻的增殖呈现波动性的变化，在五月初达到最大值；浮游动物对于蓝藻的比生长率没有显著的影响。底泥中复苏释放的蓝藻约占水柱中蓝藻生长量的2.0％左右。 (2)与绿藻混合生长的室内模拟实验显示不同温度条件下(18，25和32℃)，随着温度的升高混合培养体系中微囊藻(Microcystis aeruginosa)优势逐渐明显。在不同温度条件下(18，25和32℃)，纯培养对照组以及混合培养体系中蛋白核小球藻(Chlorella pyrenoidosa)细胞内Chl α荧光强度随着温度的升高有所增强，而铜绿微囊藻细胞内Chl α荧光强度随着温度的升高却有所减弱，混合培养时藻类酯酶活性通常低于纯培养组。本研究表明在光照适宜、高营养盐的水体中，较高的温度对铜绿微囊藻成为优势种具有明显的促进作用，进而影响着微囊藻水华的形成。 (3)群体微囊藻分离株在室内培养十八个月后仍能保持聚集状态，上浮于水表。其胞外多糖明显厚于单细胞微囊藻，透射电镜下可见明显的伪空胞。群体微囊藻胞内胞外多糖含量以及细胞内Chl α、PC和蛋白含量均高于单细胞品系。经序列比对可知群体微囊藻与单细胞微囊藻ITS序列相似性较高。更多还原

【Abstract】 Eutrophication in lakes is a serious environmental problem existing all over the country. Appearance of water bloom together with eutrophication endangers drinking-water safety, aquiculture and lake environment. During water bloom Microcystis usually become dominant species, which draws enough attention from many people. According to the four-phase development hypothesis on the cyanobacteria bloom-forming, this paper pays attention to the biological character of Microcystis during recruitment, growth and float to the water surface together with colony forming, primary conclusions are as followed:(1) During recruitment period, cyanobacteria recruitment from sediments is important seed bank for their pelagic abundance. Cyanobacteria recruitment rose with some degree of fluctuation from March to June, peaking in April; in situ growth rate of cyanobacteria also showed a general increase over the same time, only reached maximum in early May. No apparent effect of zooplankton grazing was observed on the in situ cyanobacteria growth rates. Cyanobacteria recruitment only accounted for 2.0 % of the pelagic growth.(2) During growing period together with green algae, Microcystis aeruginosa dominance became more evident together with temperature更多还原