微量元素铁、钴、钼对三种淡水藻类生长的影响

发布时间：2018-03-25 13:26

本文选题：铁　切入点：钴　出处：《河南师范大学》2017年硕士论文

【摘要】：藻类水华现象的发生往往是多种因素综合作用的结果。对于浮游藻类,微量元素的需求量虽然不多,但在浮游藻类生长的代谢过程中均有重要作用。主要作为酶的辅助因子参与到诸多的生化反应过程中,从而影响藻类的光合作用及其生长。本论文选择微量元素铁、钴、钼,研究其单独作用及联合作用对三种淡水藻类生长的影响,旨在探究不同微量元素浓度下藻类细胞密度和叶绿素a含量的变化规律及各微量元素与藻类生长指标间的相关程度,从而更有效地估计淡水水体中浮游藻类的生长情况,为预防藻类水华奠定基础。在温度为25℃,光照强度为2800 lx,光暗比为14 h:10 h的实验室条件下,选取铜绿微囊藻、小球藻和小环藻为研究藻种,在不同实验浓度的改良Fraquil培养液中培养,其中铜绿微囊藻和小球藻培养20天,小环藻培养14天。用单因素方差分析和Duncan法比较单独作用中不同实验组的差异性,拟合藻类的Logistic生长曲线并分析藻类的生长差异。联合作用实验中利用二次多项式逐步回归建立三种微量元素与藻类各生长指标间的回归方程,并根据决策系数将三种微量元素的综合作用大小进行排序。实验结果表明:(1)在微量元素铁的单独作用实验中,当铁浓度为0.6 mg/L时,铜绿微囊藻的生长情况最好;当铁浓度为1.2 mg/L时,小球藻的生长情况最好;而当铁浓度为0.3 mg/L时,小环藻的生长情况最好。在微量元素钴的单独作用实验中,当钴浓度为1.48μg/L时,铜绿微囊藻和小球藻的生长情况最好;而当钴浓度为4.44μg/L时,小环藻的生长情况最好;较高的钴浓度在实验初期对藻类有一定的刺激作用。在微量元素钼的单独作用实验中,当钼浓度为4.44μg/L时小环藻的生长情况最好;当钼浓度为1.48μg/L和5.92μg/L时,更有利于铜绿微囊藻和小球藻的细胞增殖,而钼浓度为4.44μg/L时,均有利于其叶绿素a的合成;三种淡水藻类对钼浓度均有较大的适应能力。(2)在微量元素铁、钴、钼的联合作用实验中,选择得到拟合精度较高且具有显著性的数学模型可用于估计特定条件下藻类的增殖。三种微量元素对三种淡水藻类的影响程度均不相同,其中小球藻和小环藻的各生长指标受到铁元素的影响最大,而铁元素对铜绿微囊藻的最大细胞密度、平均生长速率和最大叶绿素a含量的影响均排第二。(3)在藻类生长过程中,铜绿微囊藻和小球藻的叶绿素荧光参数Fv/Fm值的降低与其叶绿素a含量的下降具有相似性,然而在不同微量元素浓度的实验组之间,三种淡水藻类的Fv/Fm值差异并未出现明显规律,因此Fv/Fm值的变化不能较好地估计其藻类细胞的生长情况。在评估不同藻种的微量元素铁、钴、钼的营养条件时,Fv/Fm值的大小并不能完全说明该藻种的营养浓度差异。总体看来,微量元素铁、钴、钼浓度较高时会限制三种淡水藻类的生长,而较低时有利于其生长;微量元素铁对三种淡水藻类的影响范围更大。在利用Fv/Fm值的大小估计藻类的微量元素铁、钴、钼营养条件时具有一定的限制性。
[Abstract]:Algal bloom phenomenon is often the result of many factors. For phytoplankton, demand of trace elements is not much, but has an important role in the metabolic process of growth of phytoplankton. Mainly as an enzyme cofactor involved in many biochemical reaction process, thus affecting the photosynthesis and growth of algae. The trace elements of iron, cobalt, molybdenum, study their effects individually and combined effects of three species of freshwater algae growth effect, related to the degree of growth index changes to explore different trace element concentrations of algae cell density and chlorophyll a content and various trace elements and between algae, so as to effectively estimate the growth Freshwater Phytoplankton, lay the foundation for the prevention of algal bloom. At the temperature of 25 DEG, the light intensity is 2800 LX, the light dark ratio of 14 h:10 h under laboratory conditions, Selection of Microcystis aeruginosa, Chlorella and Cyclotella of algae, cultured in different concentrations of modified Fraquil experiment, the Microcystis aeruginosa and Chlorella cultivation for 20 days, Cyclotella cultured for 14 days. Differences between the different experimental groups by single factor analysis of variance and Duncan method separately in the growth difference Logistic fitting algal growth curve and algae. Stepwise regression analysis of three kinds of trace elements and algae growth index of the regression equation with two polynomial combination experiments, and according to the decision coefficient of the comprehensive effect of three kinds of trace elements on the size of the order. The experimental results show that: (1) in the experimental trace alone. Iron, when iron concentration is 0.6 mg/L, the growth of Microcystis aeruginosa is the best; when the iron concentration was 1.2 mg/L, the growth of Chlorella is best; and when the iron concentration was 0.3 mg/L, small The growth of algae. The best ring in a separate experiment on the effect of trace elements in cobalt, cobalt when the concentration is 1.48 g/L, the growth of Microcystis aeruginosa and Chlorella best; and when the cobalt concentration is 4.44 g/L, the growth of Cyclotella best; cobalt concentration has a stimulating effect on algae at the beginning of the experiment. In the experiment of the trace element molybdenum alone, when the growth of Cyclotella best molybdenum concentration is 4.44 g/L; when the molybdenum concentration is 1.48 g/L and 5.92 g/L, more conducive to Microcystis aeruginosa and Chlorella cell proliferation, and the concentration of molybdenum is 4.44 g/L, were in favor of the synthesis of chlorophyll a; adaptability of three species of freshwater algae on molybdenum concentrations were greater. (2) in trace elements of iron, cobalt, molybdenum in the combined effect experiment, mathematical model fitting accuracy and significant can be used to estimate the specific conditions of algae The influence of proliferation. Three kinds of trace elements in three species of freshwater algae are not the same, the growth index of Chlorella and Cyclotella affected by iron, iron on Microcystis maximum cell density, average growth rate and the maximum content of chlorophyll a was second (3). In the course of algae growth, decreased the chlorophyll fluorescence parameter Fv/Fm of Microcystis aeruginosa and Chlorella decreased and chlorophyll a content is similar, but in between the experimental group of different concentration of trace elements, three species of freshwater algae Fv/Fm value differences did not appear obvious tendency, so the change of Fv/Fm value can better estimate the growth the algae cells. In the assessment of trace elements iron, different species of cobalt, molybdenum nutrition condition, Fv/Fm value and can not fully explain the differences in nutrient concentration of the algae species. The total body view, Trace elements of iron, cobalt, molybdenum concentration limit of three species of freshwater algae growth, while the lower is conducive to its growth; the influence on three species of freshwater algae trace elements iron more. In the use of Fv/Fm value estimation of trace elements of iron, cobalt and algae, has certain limitations of Molybdenum Nutrition when the condition.

【学位授予单位】：河南师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X52;Q945

【参考文献】