| 摘要: |
| 三峡水库运行以来，支流暴发不同程度的蓝藻水华，香溪河库湾水体磷富营养化程度尤为突出，给三峡库区整体的水环境及水生态安全造成较大影响。沉积物是湖库水体磷富营养化的重要内源，微生物群落在沉积物的物质循环中扮演着重要角色，沉积物微生物活动能显著影响沉积物中磷的形态变化。为探究三峡水库支流香溪河库湾沉积物中微生物群落结构多样性特征及其对环境因子的响应，分别于2021年秋至2022年夏四个季节对香溪河布设的5个具有代表性点位进行取样，基于16S rRNA高通量测序分析及水质分析，对香溪河沉积物中细菌多样性及群落结构差异进行研究。结果表明：香溪河沉积物中微生物多样性丰度较高，α多样性指数总体上表现出秋季＞冬季＞春季＞夏季的季节变化规律，β多样性表现为春季库湾微生物群落差异最大，冬季差异性最小；优势菌门为变形菌门（Proteobacteria）、拟杆菌门（Bacteroidota）、酸杆菌门（Acidobacteriota）、硝化螺旋菌门（Nitrospirota）、脱硫弧菌门（Desulfobacterota）、厚壁菌门（Firmicutes）、绿弯菌门（Chloroflexi）、疣微菌门（Verrucomicrobiota）和放线菌门(Actinobacteriota)等；通过Spearman相关性分析和RDA冗余分析发现上覆水pH值、溶解氧（DO）、电导率（Spcond）、上覆水正磷酸盐（PO43-）、水温（T）和上覆水总磷（STP）是影响菌群群落结构和分布的主要环境因子，其中STP是最为关键的影响因子。本研究有助于进一步了解香溪河库湾沉积物中微生物季节性变化对库湾磷形态、含量变化的影响，为三峡库区水环境改善和管理提供参考。 |
| 关键词: 三峡水库 香溪河 微生物群落结构 多样性 时空分布特征 环境因子 |
| DOI： |
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| 基金项目:国家自然科学(51909135) |
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| SPATIAL AND TEMPORAL DISTRIBUTION OF SEDIMENT MICROBIAL COMMUNITIES IN XIANGXI RIVER OF THREE GORGES RESERVOIR |
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Liu Shuhan, Song Linxu, Luo Lina, Tang Zhaohui
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College of Hydraulic and Environment Engineering,China Three Gorges University
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| Abstract: |
| Since the operation of the Three Gorges Reservoir, the tributaries have burst out different degrees of bloom, especially the phosphorus eutrophication in Xiangxi River Bay, which has a great impact on the overall water environment and water ecological security of the Three Gorges Reservoir area. Sediment is an important internal source of phosphorus eutrophication in lake and reservoir water, and microbial community plays an important role in the element cycle of sediments, and microbial activity in sediments can significantly affect the morphological changes of phosphorus in sediments. In order to explore the diversity characteristics of microbial community structure in the sediments of Xiangxi River, a tributary of Three Gorges Reservoir, and its response to environmental factors, samples were collected at five representative sites in Xiangxi River during the four seasons from autumn 2021 to summer 2022, based on 16SrRNA high-throughput sequencing analysis and water quality analysis. The bacterial diversity and community structure differences were studied. The results showed that the abundance of microbial diversity was high in the sediments of Xiangxi River. The α diversity index showed a seasonal variation pattern of autumn > winter > spring > summer. The β diversity showed that the microbial communities in the bay had the greatest difference in spring and the least difference in winter. The dominant bacteria are Proteobacteria, Bacteroidota, Acidobacteriota, Nitrospirota, Desulfobacterota, Firmicutes, Chloroflexi, Verrucomicrobiota, Actinobacteriota and so on; Spearman correlation analysis and RDA redundancy analysis showed that overlying water pH value, dissolved oxygen (DO), electrical conductivity (Spcond), overlying water orthophosphate（PO43-）, water temperature (T) and total phosphorus (STP) in overlying water were the main environmental factors affecting the structure and distribution of bacterial community, and STP was the most critical factor. This study is helpful to further understand the effects of microbial seasonal changes on the phosphorus form and content in the sediments of the reservoir bay of Xiangxi River, and provide reference for the improvement and management of water environment in the Three Gorges Reservoir area. |
| Key words: Three Gorges Reservoir Xiangxi River Microbial community structure Diversity Spatial and temporal distribution characteristics Environmental factor |
