引用本文: | 朱智杰,陈默,薛思敏,周仕伟,焦一滢,田小方.氮和磷是影响三峡库区香溪河表层沉积物中微生物群落结构的主要因素.湖泊科学,2023,35(2):473-482. DOI:10.18307/2023.0208 |
| Zhu Zhijie,Chen Mo,Xue Simin,Zhou Shiwei,Jiao Yiying,Tian Xiaofang.Nitrogen and phosphorusas major factors shaping microbial community structures in surface sediments in Xiangxi River, Three Gorges Reservoir. J. Lake Sci.2023,35(2):473-482. DOI:10.18307/2023.0208 |
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氮和磷是影响三峡库区香溪河表层沉积物中微生物群落结构的主要因素 |
朱智杰1, 陈默1, 薛思敏1, 周仕伟1, 焦一滢2, 田小方2
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1.湖北大学资源环境学院, 区域开发与环境响应湖北省重点实验室, 武汉 430062;2.湖北工业大学土木建筑与环境学院, 河湖生态修复及藻类利用湖北省重点实验室, 武汉 430068
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摘要: |
香溪河是三峡库区最大的入库支流,目前关于香溪河沉积物微生物群落结构特征及其主要影响因素尚不明确。本研究监测香溪河上、中、下游上覆水及沉积物的主要理化指标,通过16S rDNA高通量测序研究香溪河表层沉积物中微生物群落结构特征,使用统计学软件分析细菌与理化指标间的关系。结果表明,上覆水中氨氮(NH3-N)、叶绿素a(Chl.a)浓度自下游向上游逐渐升高,其中NH3-N浓度从下游的2.04 mg/L升高到上游的3.14 mg/L。不同点位上覆水中磷酸盐(PO3-4)浓度在0.14~0.18 mg/L之间波动;同一点位间隙水中NH3-N、PO3-4浓度明显高于上覆水,10~15 cm沉积物间隙水中NH3-N与PO3-4浓度分别是0~5 cm沉积物间隙水的3.4倍和1.7倍。沉积物中Fe(Ⅱ)、Fe(Ⅲ)、酸可挥发性硫化物和铬还原性硫化物含量均表现为上游点位高于中游、下游,底层沉积物含量高于中层和表层。香溪河中游沉积物的微生物多样性和丰富度高于下游和上游,其中变形菌门(Proteobacteria)是表层沉积物中的优势菌门,鞘脂单胞菌属(Sphingomonas)为主要菌属。不同代谢功能的微生物在空间分布上存在差异,比如具有降解多环芳烃能力的外新鞘脂菌属(Novosphingobium)和土生单胞菌属(Terrimonas)在下游点位的相对丰度最高,分别达到5.8%和5.4%,硝化螺旋菌属(Nitrospira)和黄杆菌属(Flavobacterium)在中游的相对丰度最高,而铁氧化菌水杆菌属(Aquabacterium)主要分布在上游点位。冗余分析(RDA)表明总有机碳、硫酸根、Fe(Ⅱ)、氨氮和总磷是影响香溪河沉积物中微生物群落结构的主要环境因子。本研究有助于进一步了解周边环境和人为活动对香溪河水质稳定及沉积物中微生物的影响,为三峡库区水环境改善和管理提供参考。 |
关键词: 香溪河 上覆水 沉积物 微生物群落 环境因子 三峡库区 |
DOI:10.18307/2023.0208 |
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基金项目:国家自然科学基金项目(41807452)资助。 |
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Nitrogen and phosphorusas major factors shaping microbial community structures in surface sediments in Xiangxi River, Three Gorges Reservoir |
Zhu Zhijie1, Chen Mo1, Xue Simin1, Zhou Shiwei1, Jiao Yiying2, Tian Xiaofang2
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1.Key Laboratory of Regional Development and Environmental Response of Hubei Provincial, College of Resources and Environment, Hubei University, Wuhan 430062, P. R. China;2.Key Laboratory of River and Lake Ecological Restoration and Algae Utilization of Hubei Provincial, College of Civil Architecture and Environment, Hubei University of Technology, Wuhan 430068, P. R. China
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Abstract: |
Xiangxi River is the largest inflow tributary in the Three Gorges Reservoir area. Structural characteristics and influence factors of the microbial communities in sediments of Xiangxi River are not clear so far. This study investigated the main physical and chemical parameters of the overlying water (i.e., surface, middle and bottom layers) and sediments of the Xiangxi River. 16S rDNA high-throughput sequencing was used to reveal the characteristics of microbial community structures in the sediments. In addition, the relationship between bacteria and physicochemical parameters were analyzed statistically. Chlorophyll.a (Chl.a), concentrations of ammonia nitrogen (NH3-N) in the overlying water increased gradually from the downstream (2.04 mg/L) to the upstream (3.14 mg/L). The concentrations of phosphate (PO3-4) in overlying water fluctuated between 0.14 and 0.18 mg/L at different sampling sites. In addition, the concentrations of NH3-N and PO3-4 in the pore-water at the same site were significantly higher than those in the overlying water. Pore-water NH3-N and PO3-4 concentrations at 10-15 cm depth were 3.4 and 1.7 times higher than those at 0-5 cm depth in sediments, respectively. Higher contents of Fe (Ⅱ), Fe (Ⅲ), acid volatile sulfide and chromium reducing sulfide were observed in the upstream sampling sites and bottom layers of the sediments. The microbial diversity and richness in the sediments of midstream were higher compared to the sediments of downstream and upstream. Proteobacteria was the dominant phylum in the surface sediments, and Sphingomonas was the main genus. The spatial distributions of microorganisms for different metabolic activities varied. Typical bacteria with the ability to degrade polycyclic aromatic hydrocarbons, such as Novosphingobium and Terrimonas, were mainly observed in the sediments of downstream sites with percentage reaching 5.8% and 5.4%, respectively. The percentages of Nitrospira and Flavobacterium were highest in the midstream. The iron-oxidizing bacteria (i.e., Aquabacterium) were rich in the upstream sites. Redundancy analysis (RDA) showed that total organic carbon (TOC), sulfate (SO2-4), Fe (Ⅱ), NH3-N and total phosphorus (TP) were the main environmental factors shaping the microbial community structures in sediments of Xiangxi River. This study will help to further understand the impacts of surrounding environment and human activities on the stability of water quality and the microorganisms in the sediments of Xiangxi River, and provide a reference for the improvement and management of the water environment in the Three Gorges Reservoir area. |
Key words: Xiangxi River overlying water sediments microbial community structures environmental factors Three Gorges Reservoir |
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