Key Laboratory of Karst Dynamics, MNR and GZAR, Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin, 541004, China.
International Research Center on Karst Under the Auspices of UNESCO, Guilin, 541004, China.
Sci Rep. 2020 Dec 18;10(1):22296. doi: 10.1038/s41598-020-78459-z.
Although bacterioplankton play an important role in aquatic ecosystems, less is known about bacterioplankton assemblages from subtropical karst reservoirs of southwestern China with contrasting trophic status. Here, 16S rRNA gene next-generation sequencing coupled with water chemistry analysis was applied to compare the bacterioplankton communities from a light eutrophic reservoir, DL Reservoir, and a mesotrophic reservoir, WL Reservoir, in subtropical karst area of southwestern China. Our findings indicated that Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, Cyanobacteria and Verrucomicrobia dominated bacterioplankton community with contrasting relative frequency in the two subtropical karst reservoirs. Proteobacteria and Bacteroidetes were the core communities, which played important roles in karst biogeochemical cycles. Though WT, TN and DOC play the decisive role in assembling karst aquatic bacterioplankton, trophic status exerted significantly negative direct effects on bacterioplankton community composition and alpha diversity. Due to contrasting trophic status in the two reservoirs, the dominant taxa such as Enterobacter, Clostridium sensu stricto, Candidatus Methylacidiphilum and Flavobacteriia, that harbor potential functions as valuable and natural indicators of karst water health status, differed in DL Reservoir and WL Reservoir.
尽管浮游细菌在水生生态系统中发挥着重要作用，但对于中国西南具有不同营养状态的亚热带喀斯特水库中的浮游细菌组合体了解较少。本研究采用 16S rRNA 基因高通量测序结合水质分析的方法，比较了中国西南亚热带喀斯特地区富营养化的 DL 水库和中营养化的 WL 水库的浮游细菌群落。研究结果表明，在这两个亚热带喀斯特水库中，浮游细菌群落以变形菌门、厚壁菌门、放线菌门、拟杆菌门、蓝细菌门和疣微菌门为主，相对丰度存在差异。其中，变形菌门和拟杆菌门是核心类群，在喀斯特生物地球化学循环中发挥着重要作用。尽管 WT、TN 和 DOC 对喀斯特水生浮游细菌的组装起着决定性作用，但营养状态对浮游细菌群落组成和 alpha 多样性有显著的负向直接影响。由于两个水库的营养状态不同，具有潜在功能的优势类群，如肠杆菌属、严格梭菌属、产甲烷菌和黄杆菌门，作为喀斯特水健康状况的有价值的天然指示物，在 DL 水库和 WL 水库中存在差异。
