微囊藻群体形成的环境影响因素及其对磷利用的生理响应

发布时间：2018-05-14 19:29

  本文选题：铜绿微囊藻 + 环境因素　； 参考：《重庆大学》2015年硕士论文

【摘要】：水华是富营养化湖泊中浮游植物异常增殖聚集,并引起水质下降等水环境问题的现象。藻类水华是最为常见的一种。在国内外富营养化的湖泊中,蓝藻水华是最为常见的水环境问题。其中,铜绿微囊藻是危害性最大的蓝藻水华藻类。为了给蓝藻水华的有效治理提供一定的理论依据,本实验选取蓝藻的代表藻属铜绿微囊藻为研究对象,通过单因素及正交实验研究了N、P等营养盐、Ca2+浓度、光强、温度等环境因素对铜绿微囊藻生长以及群体形成的影响,实现了在实验室条件下对群体微囊藻的培养;通过对荧光倒置显微镜、扫描电子显微镜、激光共聚焦显微镜下群体微囊藻形态的观察,从微观角度解释了群体形成的生物学原因;通过在磷胁迫条件下,进行单细胞和群体两种表型的微囊藻的碱性磷酸酶(AKP)、抗氧化酶(SOD、CAT)活力的对比分析,从酶学水平解释了群体微囊藻成为优势藻种的原因以及群体形成对微囊藻水华的生物学意义。1)在单因素实验中,得出的主要结论有:铜绿微囊藻必须能够保持正常生长才能形成多而密集的群体,高Ca2+水平、高光强、适宜的温度有利于微囊藻群体的形成。利于铜绿微囊藻群体形成的N、P浓度水平是N=10mg/L、P=0.5mg/L,N=50mg/L、P=2.5mg/L,N=100mg/L、P=5mg/L;Ca2+浓度水平为Ca2+=130mg/L、Ca2+=260mg/L、Ca2+=520mg/L;光强水平为4000 lux、8000 lux、12000 lux;温度水平为15℃、20℃、25℃。2)在正交实验中,得出的结论是:与单环境因素条件相比,多环境因素的共同作用更能促进微囊藻群体的形成;群体形成的环境条件最佳组合是初始浓度N=100mg/L、P=5mg/L、Ca2+=260mg/L,光强为4000 lux,温度保持在25℃。3)在对单细胞和群体两种表型的微囊藻进行了形态上的比较后,可以推断出:微囊藻形成群体的方式有两种,一是将单细胞聚集起来集结成群体,二是进行分裂增殖积累细胞数目形成群体。这两种方式存在一个递进的关系,即单细胞聚集起来形成的小群体通过细胞分裂增殖形成大群体。但也不绝对,在微囊藻生长的复杂的生态系统中,这两种方式通常是并存的。群体在形成的过程中,多糖(EPS)胶鞘起着粘结细胞、保护细胞、提供营养物质、辅助调节浮力等的作用,Ca2+的存在更是加强了细胞聚集的稳定性。4)在缺磷胁迫下对单细胞和群体两种表型的微囊藻进行了AKP、SOD、CAT活力对比后可以知道:缺磷胁迫条件下,单细胞的AKP活力显著上升,而群体的较低AKP活力则证明了在营养波动较大的环境中,群体能竞争营养物质(如磷)保持优势生长;群体较高的抗氧化酶(SOD、CAT)活力也保证了其及时去除体内多余的活性氧,增强抵抗逆境胁迫伤害的能力。
[Abstract]:Shui Hua is a phenomenon that phytoplankton abnormally proliferates and accumulates in eutrophic lakes and causes water environmental problems such as water quality decline. Algae Shui Hua is the most common species. Cyanobacteria Shui Hua is the most common water environmental problem in eutrophication lakes at home and abroad. Among them, microcystis aeruginosa is the most harmful cyanobacteria Shui Hua algae. In order to provide some theoretical basis for the effective control of cyanobacteria Shui Hua, the representative alga of cyanobacteria, Microcystis aeruginosa, was selected as the research object. The effects of temperature and other environmental factors on the growth and population formation of microcystis aeruginosa were studied. The morphology of microcystis was observed under confocal laser microscope, and the biological reasons of colony formation were explained from the microcosmic point of view. The activity of alkaline phosphatase (AKP) and antioxidant enzyme (SOD CAT) of microcystis with single cell and population phenotypes were compared and analyzed. The reason why microcystis became dominant algae species and the biological significance of colony formation to microcystis Shui Hua were explained from the level of enzyme. The main conclusions are as follows: microcystis aeruginosa must be able to maintain normal growth in order to form a large and dense population, high Ca2 level, high light intensity, the appropriate temperature is conducive to the formation of microcystis. The concentration of NNP in microcystis aeruginosa population is 10 mg / L, 0.5 mg / L, 50 mg / L, 2.5 mg / L, 5 mg 路L ~ (-1) of Ca ~ (2 2), which is Ca2 130 mg / L Ca ~ (2 2) 260 mg 路L ~ (2 +), 4000 luxlux8000 ~ (12) mg / L, light intensity, 15 鈩，

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