Functional properties of bacterial communities in water and sediment of the eutrophic river-lake system of Poyang Lake, China

Abstract

In river-lake systems, sediment and water column are two distinct habitats harboring different bacterial communities which play a crucial role in biogeochemical processes. In this study, we employed Phylogenetic Investigation of Communities by Reconstruction of Unobserved States to assess the potential functions and functional redundancy of the bacterial communities in sediment and water in a eutrophic river-lake ecosystem, Poyang Lake in China. Bacterial communities in sediment and water had distinct potential functions of carbon, nitrogen, and sulfur metabolisms as well as phosphorus cycle, while the differences between rivers and the lake were inconspicuous. Bacterial communities in sediment had a higher relative abundance of genes associated with carbohydrate metabolism, carbon fixation pathways in prokaryotes, methane metabolism, anammox, nitrogen fixation, and dissimilatory sulfate reduction than that of water column. Bacterial communities in water column were higher in lipid metabolism, assimilatory nitrate reduction, dissimilatory nitrate reduction, phosphonate degradation, and assimilatory sulfate reduction than that of sediment bacterial communities. Furthermore, the variations in functional composition were closely associated to the variations in taxonomic composition in both habitats. In general, the bacterial communities in water column had a lower functional redundancy than in sediment. Moreover, comparing to the overall functions, bacterial communities had a lower functional redundancy of nitrogen metabolism and phosphorus cycle in water column and lower functional redundancy of nitrogen metabolism in sediment. Distance-based redundancy analysis and mantel test revealed close correlations between nutrient factors and functional compositions. The results suggested that bacterial communities in this eutrophic river-lake system of Poyang Lake were vulnerable to nutrient perturbations, especially the bacterial communities in water column. The results enriched our understanding of the bacterial communities and major biogeochemical processes in the eutrophic river-lake ecosystems.

Profiling the microbial community structure and functional diversity of a dam‐regulated river undergoing gravel bar restoration

“…Furthermore, we found a significant positive correlation between taxonomic and functional diversity, suggesting that differences in the putative metabolic functions were closely related to dissimilarities in community composition. Likewise, closely associated variations in taxonomic and functional composition have been reported on eutrophic river-lake water and sediment bacteria (Ren et al, 2019) and marine microbial communities on both temporal and spatial scales (Galand et al, 2015(Galand et al, , 2018. The linear relationship of functional diversity dissimilarity with increasing community dissimilarity was not observed from previous studies that used taxonomic profiles to annotate the functional potential of the microbial communities from marine samples (Louca et al, 2016).…”

Trophic Status Is Associated With Community Structure and Metabolic Potential of Planktonic Microbiota in Plateau Lakes

“…Although sulfur cycling in freshwater sediments and vertical water columns has been well studied (Cai et al, 2019; Ren et al, 2019), the genetic potential for sulfur transformation in surface waters of lakes with different trophic status has not been studied. With the death of a large number of Cyanobacteria in eutrophic lakes, the high content of sulfur-containing amino acids in their cells might be released (Lu et al, 2013), resulting in a water column enriched with organic sulfur.…”

Short-Term Thinning Influences the Rhizosphere Fungal Community Assembly of Pinus massoniana by Altering the Understory Vegetation Diversity

“…The total potassium (TK) content and the available potassium (AK) content were determined using the Bao method ( Bao, 2000 ). Total phosphorus (TP) was measured using the alkali fusion-Mo-Sb anti spectrophotometric method, and Available phosphorus (AP) was measured using the sodium hydrogen carbonate solution-Mo-Sb anti spectrophotometric method ( Ren et al, 2019 ). The Patrick richness index (R), Simpson index (D), Pielou index (J), and Shannon index (H) were used to evaluate understory vegetation diversity ( Cheng et al, 2016 ).…”