环境因子对铜绿微囊藻生长及产毒的影响研究

发布时间：2017-12-28 22:14

本文关键词：环境因子对铜绿微囊藻生长及产毒的影响研究　出处：《辽宁大学》2015年硕士论文　论文类型：学位论文

【摘要】：我国处于富营养化状态的湖泊水库已达80%以上,它已经严重威胁到生态环境的可持续发展。同时,大多数富营养化水体中优势藻主要为微囊藻,其中又以铜绿微囊藻(Microcysis)为主。铜绿微囊藻是一种产毒藻,它能产生微囊藻毒素,并且微囊藻毒素是毒性最高的一种蓝藻毒素。一直以来很多学者都在研究水华和藻毒素发生的原因,但尚未得到较为统一的结论。本文以研究较多的水华蓝藻-铜绿微囊藻为试验对象,通过室内培养,探索温度、光照强度、氮、磷对其生物量及产毒量的影响。(1)通过单因素分析方法,分别探索温度、光照强度、总氮、总磷四个因素对铜绿微囊藻生物量以及产毒量的影响,每个因素分别进行23天的试验,每隔一天测定铜绿微囊藻藻细胞密度和叶绿素a的变化情况来反应其生物量,每隔三天测定铜绿微囊藻胞内及胞外微囊藻毒素-LR的含量。试验表明,铜绿微囊藻在温度为30℃、光照强度为1000 Lux时生长最快,而在25℃、500 Lux时产生的藻毒素含量最多;随着培养基总氮浓度的升高,铜绿微囊藻生物量以及产藻毒素的含量增多,较低浓度的总磷就可以满足铜绿微囊藻的生长和产毒;总氮浓度为60 mg·L-1,总磷浓度为0.6 mg·L-1,氮磷比100:1时,最适合铜绿微囊藻生长和产毒。综上也可以发现最适合铜绿微囊藻的产毒条件不同于其最佳的生长条件。(2)在单因素探索的基础上,采用四因素三水平的正交试验方法,研究温度、光照强度、总氮、总磷不同水平组合下铜绿微囊藻生物量以及产毒量的变化情况。铜绿微囊藻进行为期29天的试验,每隔一天测定其藻细胞密度和藻液吸光度来反应其生物量变化,每隔三天测定其产生微囊藻毒素-LR的含量。试验结果表明,四个因素对铜绿微囊藻生长的影响顺序:光照强度㧐温度㧐总氮㧐总磷;光照强度对铜绿微囊藻的生长具有显著影响,而温度、总氮、总磷对铜绿微囊藻的生长没有显著影响;四因素对铜绿微囊藻产毒量影响最显著的条件为光照强度,其次为总磷和总氮,影响程度最小的为温度;铜绿微囊藻产毒量随着总磷浓度的增加呈现先增大后降低的趋势,本试验最适合其产毒的总磷浓度为0.6 mg·L-1,铜绿微囊藻产毒量随着光照强度、温度和总氮的降低而增加,最适合其产毒的光照强度为200 Lux,温度为22℃,总氮浓度为20 mg·L-1。
[Abstract]:The lake and reservoir in the state of eutrophication in China have reached more than 80%, which has seriously threatened the sustainable development of the ecological environment. At the same time, the Dominant Algae in most eutrophic water bodies are Microcystis, among them, Microcystis aeruginosa (Microcysis) is the main type of algae. Microcystis aeruginosa is a kind of poisonous algae, it can produce microcystin, and microcystin is the most toxic cyanobacteria toxin. Many scholars have been studying the causes of the occurrence of blooms and alga toxins, but have not yet obtained a more unified conclusion. In this paper, we studied the influence of temperature, light intensity, nitrogen and phosphorus on biomass and yield of microalgae, which were studied more in water bloom, cyanobacteria and Microcystis aeruginosa. (1) by using single factor analysis method, respectively explore the temperature, light intensity, total nitrogen and total phosphorus four factors on Microcystis biomass and toxin production, each factor test was carried out for 23 days, every day the determination of changes of Microcystis aeruginosa algal cell density and chlorophyll a in response to the biomass, the content of every three days by Microcystis aeruginosa intracellular and extracellular microcystin -LR. The test showed that Microcystis aeruginosa at the temperature of 30 DEG, the light intensity of 1000 Lux growth is the fastest, most of the toxin content produced at 25 DEG C and 500 Lux; with the increase of total nitrogen concentration in culture medium, the biomass of Microcystis aeruginosa increased and the content of microcystins, total phosphorus concentration is low you can meet the growth of Microcystis aeruginosa and toxin production; the total nitrogen concentration of 60 mg L-1, total phosphorus concentration of 0.6 mg L-1, nitrogen and phosphorus ratio of 100:1, the most suitable for the growth of Microcystis aeruginosa and toxin production. It is also found that the most suitable conditions for the production of Microcystis aeruginosa are different from the best growth conditions. (2) on the basis of single factor exploration, four factors and three levels of orthogonal test were used to study the changes of biomass and yield of Microcystis aeruginosa under different combinations of temperature, light intensity, total nitrogen and total phosphorus. Microcystis aeruginosa was tested for 29 days. The algal cell density and algal fluid absorbance were measured every other day to reflect their biomass changes. The content of microcystin -LR was measured every three days. Experimental results show that the effect of the order of four factors on the growth of Microcystis aeruginosa: light intensity? Temperature? Total nitrogen? Phosphorus; light intensity on the growth of Microcystis aeruginosa has significant effect, while there was no significant effect of temperature, total nitrogen and total phosphorus on the growth of Microcystis aeruginosa; effects of four factors on Microcystis aeruginosa virus yield of light intensity was the most significant, followed by the total nitrogen and total phosphorus, the minimal impact of temperature; Microcystis aeruginosa toxin production with increased at first and then decreased total phosphorus concentration increased, the most suitable for its toxin producing the total phosphorus concentration of 0.6 mg L-1, Microcystis aeruginosa algal toxin production increases with the decrease of light intensity, temperature and total nitrogen, the most suitable for the toxin production of light intensity is 200 Lux, the temperature is 22 DEG C, total nitrogen concentration of 20 mg L-1.
【学位授予单位】：辽宁大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X524

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