Qin Yu, Tang Qiong, Lu Lunhui, Wang Yuchun, Izaguirre Irina, Li Zhe
Key Laboratory of Hydraulic and Waterway Engineering of the Ministry of Education, Chongqing Jiaotong University, Chongqing, 400074, China.
Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China.
Appl Microbiol Biotechnol. 2021 Jan;105(2):839-852. doi: 10.1007/s00253-020-11047-3. Epub 2021 Jan 6.
Bacterial communities play an important role in the biogeochemical cycle in reservoir ecosystems. However, the dynamic changes in both planktonic and sediment bacterial communities in a highly regulated dam reservoir remain unclear. This study investigated the temporal distribution patterns of bacterial communities in a transition section of the Three Gorges Reservoir (TGR) using Illumina MiSeq sequencing. Results suggested that in comparison to the planktonic bacteria, sediment bacteria contributed more to the reservoir microbial communities, accounting for 97% of the 7434 OTUs. The Shannon diversity index in the water (3.225.68) was generally lower than that in the sediment (6.727.56). In the high water level period (January and March), Proteobacteria, Actinobacteria, Cyanobacteria, and Firmicutes were the most abundant phyla, whereas in the low water level period (May, July, and September), the dominant phyla were Proteobacteria, Actinobacteria, and Bacteroidetes. Sediment samples were dominated by Proteobacteria, Chloroflexi, and Acidobacteria. Principal coordinate analysis of the bacterioplankton communities showed greater sensitivity to monthly changes than that of the sediment bacterial communities. Network analysis suggested that in comparison to planktonic bacterial communities, sediment bacterial communities were more complex and stable. The linear relationship between the CH/CO ratio, water level, and relative abundance of methanotrophs highlighted the potential methane-oxidizing process in the mid-part of the TGR. Moreover, the potential impact of dam regulation on the bacterial communities was revealed by the significant relationship between abundant phyla and the inflow of the TGR. KEY POINTS: • Bacterioplankton communities showed great sensitivity to monthly changes. • Potential methane-oxidizing process was revealed in this representative area. • Water inflow regulated by dam has significant effects on dominant bacterioplankton.
细菌群落对水库生态系统的生物地球化学循环起着重要作用。然而，在调控程度高的大坝水库中，浮游细菌群落和沉积物细菌群落的动态变化仍不清楚。本研究利用Illumina MiSeq测序技术，调查了三峡水库（TGR）过渡段细菌群落的时间分布模式。结果表明，与浮游细菌相比，沉积物细菌对水库微生物群落的贡献更大，占7434个操作分类单元（OTU）的97%。水体中的香农多样性指数（3.225.68）总体低于沉积物中的（6.727.56）。在高水位期（1月和3月），变形菌门、放线菌门、蓝细菌门和厚壁菌门是最丰富的门类，而在低水位期（5月、7月和9月），优势门类为变形菌门、放线菌门和拟杆菌门。沉积物样本以变形菌门、绿弯菌门和酸杆菌门为主。浮游细菌群落的主坐标分析显示，其对月度变化的敏感性高于沉积物细菌群落。网络分析表明，与浮游细菌群落相比，沉积物细菌群落更复杂、更稳定。CH/CO比值、水位与甲烷氧化菌相对丰度之间的线性关系突出了三峡水库中部潜在的甲烷氧化过程。此外，优势门类与三峡水库入流量之间的显著关系揭示了大坝调控对细菌群落的潜在影响。
• 浮游细菌群落对月度变化表现出高度敏感性。
• 在这个代表性区域揭示了潜在的甲烷氧化过程。
• 大坝调节的入流水对优势浮游细菌有显著影响。
