环渤海沉积物多环芳烃芘胁迫下细菌群落变化的研究

发布时间：2018-06-13 14:34

本文选题：芘 + 多环芳烃　；参考：《齐鲁工业大学》2016年硕士论文

【摘要】：多环芳烃(polycyclic aromatic hydrocarbons,PAHs)是一类典型的持久性有机污染物,其主要产生来源为人类的生产活动。其较长的半衰期导致易在环境中累积而引起严重的环境问题。在海洋沉积物中,微生物是环境自我净化多环芳烃污染的主力。渤海是我国北方半封闭海,快速发展的环渤海经济区对其生态系统产生了显著影响。目前为止,关于渤海污染及生态现状的研究多集中在污染物种类及分布上,但关于渤海海域微生物群落结构特征及其对多环芳烃污染胁迫的响应的研究尚不足。本文拟选取渤海湾及莱州湾口这一渤海海域受人类活动影响最为显著的区域为研究对象,利用高通量测序(Illumina Hiseq PE250)及分析技术,以16s为标记基因,探索目标海域表层沉积物中的微生物群落结构;进一步以该海域表层沉积物中细菌群落为富集培养对象,在实验室条件下添加高浓度芘进行胁迫。再次利用高通量测序(Illumina Hiseq PE250)及分析技术,以16s为标记基因探索在实验室模拟条件下渤海海域表层沉积物中细菌群落结构对芘胁迫的响应。结果表明:1.广泛存在于目标海域22个研究站位沉积物中的主要细菌类群包括:变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)、绿弯菌门(Chloroflexi)和拟杆菌门(Bacteroidetes)。变形菌门中主要包括γ-变形杆菌纲、δ-变形菌纲、α-变形菌纲,并且γ-变形杆菌纲是优势菌群。在科水平上含量较多的菌群主要是变形菌门的沍立克次体科(Piscirickettsiaceae),与鱼类疾病有关;变形菌门的脱硫杆菌科(Desulfobacteraceae)和红杆菌科(Rhodobacteraceae),与硫循环和碳循环有关。2.目标海域原位环境中微生物的群落结构受粒径、深度、温度、有机碳及NO2-、NO3-的影响较大。黄河、滦河入海口处,外来沉积物的输入致使入海口处有机质含量增高;河水的径流作用使近岸沉积物粒径减小,从而影响不同站位微生物群落结构。3.室内受控模拟实验结果表明,芘胁迫后细菌群落结构发生了比较明显的变化。丰富度较高的菌群主要有:变形菌门(Proteobacteria,86.19%)、拟杆菌门(Bacteroidetes,10.00%)、酸杆菌门(Acidobacteria)、绿弯菌门(Chloroflexi)和浮霉菌门(Planctomycetes)。驯化过程中数量不断增加的细菌主要有浮霉状菌属、黄杆菌属和芽孢杆菌属;数量减少的细菌是脱硫杆菌属;菌数先增加后减少的主要有弧菌属、假海源杆菌属、海杆菌属和假交替单胞菌属。除脱硫杆菌属外,其余均有降解多环芳烃的功能。
[Abstract]:Polycyclic aromatic hydrocarbons (PAHs) are a typical class of persistent organic pollutants (pops), which are mainly produced by human production activities. Its long half-life can easily accumulate in the environment and cause serious environmental problems. In marine sediments, microbes are the main source of environmental self-purification polycyclic aromatic hydrocarbons (PAHs) pollution. The Bohai Sea is a semi-enclosed sea in the north of China. The rapid development of the Bohai Sea Economic Zone has a significant impact on its ecosystem. Up to now, the study on the pollution and ecological status of Bohai Sea is mainly focused on the species and distribution of pollutants, but the study on the structure of microbial community and its response to PAHs pollution stress in Bohai Sea is still insufficient. In this paper, we choose Bohai Bay and Laizhou Bay estuary, which is the most affected area of Bohai Sea, as the research object, and use high-throughput sequencing (Illumina Hiseq PE250) and analysis technique to use 16s as marker gene. The microbial community structure in the surface sediment of the target sea area was explored, and the bacterial community in the surface sediment of the target sea area was taken as the enrichment culture object under the stress of adding high concentration of pyrene under laboratory conditions. Using high-throughput sequencing technique, Illumina Hiseq PE250) and analysis technique, 16s marker gene was used to explore the response of bacterial community structure to pyrene stress in the surface sediments of Bohai Sea under laboratory simulation. The result shows that 1: 1. The main bacteria groups in the sediments of 22 research stations in the target sea area include Proteobacteriae, acidobacteria, Chloroflexium and Bacteroidetes.These include Proteobacteriae, Acidobacteria, Chloroflexia and Bacteroidetes. The phylum of Proteus mainly includes 纬 -Proteus, 未 -Proteus, 伪 -Proteus, and 纬 -Proteus is the dominant group. At the level of family, the most abundant bacteria were Piscirickettsiaceaeae of Proteus, related to fish disease, Desulfobacteraceaeae of Proteus and Rhodobacteraceaeae of Rhodobacteraceaeae, which were related to sulfur cycle and carbon cycle. The community structure of microorganisms in the target sea area in situ was influenced by particle size, depth, temperature, organic carbon and no _ 2-no _ 3-. At the mouth of the Yellow River and Luanhe River, the content of organic matter in the estuary was increased by the input of foreign sediment, and the grain size of the sediment was reduced by the runoff of the river, which affected the microbial community structure of different stations. The results of laboratory controlled simulation showed that the community structure of bacteria changed obviously after pyrene stress. The most abundant bacteria were Proteobacteria, Bacteroidetes10.00, Acidobacteria, Chloroflexium and Planctomycetes. During the process of acclimation, the main bacteria increasing in number are the genus floatation, the genus Flavobacterium and the genus Bacillus; the decreasing number of bacteria is the genus Desulfurbacteria; the main bacteria that increase first and then decrease are the genus Vibrio, the genus Pseudomonas, Haemobacterium and Pseudomonas. Except Desulfurization bacilli, the other have the function of degrading PAHs.
【学位授予单位】：齐鲁工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X55

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