scholarly journals Comparison of Prokaryotic Communities Associated with Different TOC Concentrations in Dianchi Lake

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2557
Author(s):  
Cheng-Peng Li ◽  
Ya-Ping Li ◽  
Qing-Qing Huo ◽  
Wei Xiao ◽  
Chang-Qun Duan ◽  
...  
Keyword(s):  
Community Structure ◽  
Organic Carbon ◽  
Lake Sediment ◽  
Bacterial Communities ◽  
Meta Analysis ◽  
Eutrophic Lake ◽  
Dianchi Lake ◽  
Prokaryotic Community ◽  
Eutrophic Lakes

The effect of total organic carbon (TOC) on the prokaryotic community structure in situ has been rarely known. This study aimed to determine the effect of TOC level on the composition and networks of archaeal and bacterial communities in the sediments of Dianchi Lake, one of the most eutrophic lakes in China. Microbial assemblages showed significantly associations with TOC. Moreover, relatively high and low TOC formed taxonomic differences in prokaryotic assemblages. According to the results, the most abundant bacteria across all samples were identified as members of the phyla Proteobacteria, Nitrospirae, Chloroflexi, Firmicutes and Ignavibacteriae. The dominant groups of archaea consisted of Euryarchaeota, Woesearchaeota DHVEG-6, Bathyarchaeota and WSA2. Lastly, the meta-analysis results highlighted that the low TOC (LT) prokaryotic community structure is larger and more complex compared to moderate TOC (MT). On the whole, the prokaryotic community structure is obviously distinct among groups with different TOC levels, and LT communities may interact with each other strongly in the Dianchi Lake sediment. This study can provide more insights into prokaryotic assemblages in eutrophic lake sediment and provide suggestions for the restoration and maintenance of sediment ecosystems.

scholarly journals Response of Prokaryotes to TOC Contamination in Dianchi Lake Sediments

2020 ◽  
Author(s):  
Cheng-Peng Li ◽  
Ya-Ping Li ◽  
Qing-Qing Huo ◽  
Wei Xiao ◽  
Yong-Xia Wang ◽  
...  
Keyword(s):  
Lake Sediment ◽  
Meta Analysis ◽  
Eutrophic Lake ◽  
Nucleotide Metabolism ◽  
Microbial Consortia ◽  
Dianchi Lake ◽  
Strongly Correlated ◽  
Eutrophic Lakes ◽  
And Function ◽  
Functional Profiles

Abstract Background: Explaining microbial consortia in sediments from the perspective of taxon, co-occurrence and function is the key to recover and maintain aquatic ecosystems. Trophic status was widely considered to be an important determinant of the lake sediment microbial community. However, little is known about the effect of a special eutrophic factor gradient on the prokaryotic community structure in situ. Within this context, we explored prokaryotic communities using an intensive field sampling from sediments in the Dianchi Lake, one of the most eutrophic lakes in China. Results: Microbial assemblages was strongly correlated with total organic carbon (TOC). Moreover, relatively high and low TOC shaped taxonomic and functional differences in microbial assemblages. The results identified the most abundant bacteria across all samples as Proteobacteria , Nitrospirae , Chloroflexi , Firmicutes , Ignavibacteriae , Actinobacteria , Bacteroidetes , Acidobacteria , Spiprochaetae and Latescibacteria . The dominant groups of archaea were Euryarchaeota , Woesearchaeota DHVEG-6 , Bathyarchaeota and WSA2 . Low TOC (LT) microbial assemblages displayed a major proportion of functional profiles related to some metabolisms such as carbohydrate metabolism, amino acid metabolism, energy metabolism, nucleotide metabolism and metabolism of cofactors and vitamins, membrane transport. These results illustrated that TOC concentration had obvious influence on the relative abundances of KEGG orthologs . Finally, the meta-analysis results highlight that most of network parameters of the LT community were significantly greater than those of other communities, which suggesting that the LT community was larger and more complex. Conclusion: TOC level might be a key determinant to shape taxonomic and functional construction of communities in Dianchi Lake sediment. LT community tended to establish a larger and more complex co-occurrence, which suggested that they may interact with each other strongly and exchange essential metabolites. Overall, this study could enhance our knowledge of microbial assemblages in eutrophic lake sediment and provide clues for the restoration and maintenance of sediment ecosystems.

scholarly journals Effects of eutrophication on sedimentary organic carbon cycling in five temperate lakes

2019 ◽  
Vol 16 (19) ◽  
pp. 3725-3746 ◽  
Author(s):  
Annika Fiskal ◽  
Longhui Deng ◽  
Anja Michel ◽  
Philip Eickenbusch ◽  
Xingguo Han ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Water Column ◽  
Trophic State ◽  
Microbial Respiration ◽  
Accumulation Rate ◽  
Eutrophic Lake ◽  
Accumulation Rates ◽  
Artificial Lake ◽  
Eutrophic Lakes ◽  
Lake Ecosystems

Abstract. Even though human-induced eutrophication has severely impacted temperate lake ecosystems over the last centuries, the effects on total organic carbon (TOC) burial and mineralization are not well understood. We study these effects based on sedimentary records from the last 180 years in five Swiss lakes that differ in trophic state. We compare changes in TOC content and modeled TOC accumulation rates through time to historical data on algae blooms, water column anoxia, wastewater treatment, artificial lake ventilation, and water column phosphorus (P) concentrations. We furthermore investigate the effects of eutrophication on rates of microbial TOC mineralization and vertical distributions of microbial respiration reactions in sediments. Our results indicate that the history of eutrophication is well recorded in the sedimentary record. Overall, eutrophic lakes have higher TOC burial and accumulation rates, and subsurface peaks in TOC coincide with past periods of elevated P concentrations in lake water. Sediments of eutrophic lakes, moreover, have higher rates of total respiration and higher contributions of methanogenesis to total respiration. However, we found strong overlaps in the distributions of respiration reactions involving different electron acceptors in all lakes regardless of lake trophic state. Moreover, even though water column P concentrations have been reduced by ∼ 50 %–90 % since the period of peak eutrophication in the 1970s, TOC burial and accumulation rates have only decreased significantly, by ∼ 20 % and 25 %, in two of the five lakes. Hereby there is no clear relationship between the magnitude of the P concentration decrease and the change in TOC burial and accumulation rate. Instead, data from one eutrophic lake suggest that artificial ventilation, which has been used to prevent water column anoxia in this lake for 35 years, may help sustain high rates of TOC burial and accumulation in sediments despite water column P concentrations being strongly reduced. Our study provides novel insights into the influence of human activities in lakes and lake watersheds on lake sediments as carbon sinks and habitats for diverse microbial respiration processes.

scholarly journals Carbon sources supporting benthic mineralization in mangrove and adjacent seagrass sediments (Gazi Bay, Kenya)

2004 ◽  
Vol 1 (1) ◽  
pp. 71-78 ◽  
Author(s):  
S. Bouillon ◽  
T. Moens ◽  
F. Dehairs
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Bacterial Communities ◽  
Carbon Sources ◽  
Mangrove Ecosystem ◽  
Significant Source ◽  
Community Respiration ◽  
Seagrass Beds ◽  
Gazi Bay

Abstract. The origin of carbon substrates used by in situ sedimentary bacterial communities was investigated in an intertidal mangrove ecosystem and in adjacent seagrass beds in Gazi bay (Kenya) by δ13C analysis of bacteria-specific PLFA (phospholipid fatty acids) and bulk organic carbon. Export of mangrove-derived organic matter to the adjacent seagrass-covered bay was evident from sedimentary total organic carbon (TOC) and δ13CTOC data. PLFA δ13C data indicate that the substrate used by bacterial communities varied strongly and that exported mangrove carbon was a significant source for bacteria in the adjacent seagrass beds. Within the intertidal mangrove forest, bacterial PLFA at the surface layer (0-1cm) typically showed more enriched δ13C values than deeper (up to 10cm) sediment layers, suggesting a contribution from microphytobenthos and/or inwelled seagrass material. Under the simplifying assumption that seagrasses and mangroves are the dominant potential end-members, the estimated contribution of mangrove-derived carbon to benthic mineralization in the seagrass beds (16-74%) corresponds fairly well to the estimated contribution of mangrove C to the sedimentary organic matter pool (21-71%) across different seagrass sites. Based on the results of this study and a compilation of literature data, we suggest that trapping of allochtonous C is a common feature in seagrass beds and often represents a significant source of C for sediment bacteria - both in cases where seagrass C dominates the sediment TOC pool and in cases where external inputs are significant. Hence, it is likely that data on community respiration rates systematically overestimate the role of in situ mineralization as a fate of seagrass production.

scholarly journals Colonization Habitat Controls Biomass, Composition, and Metabolic Activity of Attached Microbial Communities in the Columbia River Hyporheic Corridor

2017 ◽  
Vol 83 (16) ◽  
Author(s):  
Noah Stern ◽  
Matthew Ginder-Vogel ◽  
James C. Stegen ◽  
Evan Arntzen ◽  
David W. Kennedy ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Organic Carbon ◽  
Microbial Communities ◽  
River Water ◽  
Hyporheic Zone ◽  
Columbia River ◽  
Fluid Source ◽  
Hydrologic Exchange

ABSTRACT Hydrologic exchange plays a critical role in biogeochemical cycling within the hyporheic zone (the interface between river water and groundwater) of riverine ecosystems. Such exchange may set limits on the rates of microbial metabolism and impose deterministic selection on microbial communities that adapt to dynamically changing dissolved organic carbon (DOC) sources. This study examined the response of attached microbial communities (in situ colonized sand packs) from groundwater, hyporheic, and riverbed habitats within the Columbia River hyporheic corridor to “cross-feeding” with either groundwater, river water, or DOC-free artificial fluids. Our working hypothesis was that deterministic selection during in situ colonization would dictate the response to cross-feeding, with communities displaying maximal biomass and respiration when supplied with their native fluid source. In contrast to expectations, the major observation was that the riverbed colonized sand had much higher biomass and respiratory activity, as well as a distinct community structure, compared with those of the hyporheic and groundwater colonized sands. 16S rRNA gene amplicon sequencing revealed a much higher proportion of certain heterotrophic taxa as well as significant numbers of eukaryotic algal chloroplasts in the riverbed colonized sand. Significant quantities of DOC were released from riverbed sediment and colonized sand, and separate experiments showed that the released DOC stimulated respiration in the groundwater and piezometer colonized sand. These results suggest that the accumulation and degradation of labile particulate organic carbon (POC) within the riverbed are likely to release DOC, which may enter the hyporheic corridor during hydrologic exchange, thereby stimulating microbial activity and imposing deterministic selective pressure on the microbial community composition. IMPORTANCE The influence of river water-groundwater mixing on hyporheic zone microbial community structure and function is an important but poorly understood component of riverine biogeochemistry. This study employed an experimental approach to gain insight into how such mixing might be expected to influence the biomass, respiration, and composition of hyporheic zone microbial communities. Colonized sands from three different habitats (groundwater, river water, and hyporheic) were “cross-fed” with either groundwater, river water, or DOC-free artificial fluids. We expected that the colonization history would dictate the response to cross-feeding, with communities displaying maximal biomass and respiration when supplied with their native fluid source. By contrast, the major observation was that the riverbed communities had much higher biomass and respiration, as well as a distinct community structure compared with those of the hyporheic and groundwater colonized sands. These results highlight the importance of riverbed microbial metabolism in organic carbon processing in hyporheic corridors.

scholarly journals Organic carbon mass accumulation rate regulates the flux of reduced substances from the sediments of deep lakes

2017 ◽  
Vol 14 (13) ◽  
pp. 3275-3285 ◽  
Author(s):  
Thomas Steinsberger ◽  
Martin Schmid ◽  
Alfred Wüest ◽  
Robert Schwefel ◽  
Bernhard Wehrli ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Accumulation Rate ◽  
Eutrophic Lake ◽  
Deep Lakes ◽  
Deep Basin ◽  
Eutrophic Lakes ◽  
Mass Accumulation Rate ◽  
Carbon Mass ◽  
Major Factors ◽  
Mass Accumulation

Abstract. The flux of reduced substances, such as methane and ammonium, from the sediment to the bottom water (Fred) is one of the major factors contributing to the consumption of oxygen in the hypolimnia of lakes and thus crucial for lake oxygen management. This study presents fluxes based on sediment porewater measurements from different water depths of five deep lakes of differing trophic states. In meso- to eutrophic lakes Fred was directly proportional to the total organic carbon mass accumulation rate (TOC-MAR) of the sediments. TOC-MAR and thus Fred in eutrophic lakes decreased systematically with increasing mean hypolimnion depth (zH), suggesting that high oxygen concentrations in the deep waters of lakes were essential for the extent of organic matter mineralization leaving a smaller fraction for anaerobic degradation and thus formation of reduced compounds. Consequently, Fred was low in the 310 m deep meso-eutrophic Lake Geneva, with high O2 concentrations in the hypolimnion. By contrast, seasonal anoxic conditions enhanced Fred in the deep basin of oligotrophic Lake Aegeri. As TOC-MAR and zH are based on more readily available data, these relationships allow estimating the areal O2 consumption rate by reduced compounds from the sediments where no direct flux measurements are available.

scholarly journals Spatial-Temporal Variation of Bacterial Communities in Sediments in Lake Chaohu, a Large, Shallow Eutrophic Lake in China

2019 ◽  
Vol 16 (20) ◽  
pp. 3966 ◽  
Author(s):  
Lei Zhang ◽  
Yu Cheng ◽  
Guang Gao ◽  
Jiahu Jiang
Keyword(s):  
Community Structure ◽  
Bacterial Communities ◽  
Environmental Changes ◽  
Eutrophic Lake ◽  
Lake Chaohu ◽  
Lake Ecosystems ◽  
Linear Discriminant ◽  
Community Function ◽  
Spatial Changes ◽  
Sudden Appearance

Sediment bacterial communities are critical for the circulation of nutrients in lake ecosystems. However, the bacterial community function and co-occurrence models of lakes have not been studied in depth. In this study, we observed significant seasonal changes and non-significant spatial changes in the beta diversity and community structure of sediment bacteria in Lake Chaohu. Through linear discriminant analysis effect size (LEfSe), we observed that certain taxa (from phylum to genus) have consistent enrichment between seasons. The sudden appearance of a Firmicutes population in spring samples from the Zhaohe River, an estuary of Lake Chaohu, and the dominance of Firmicutes populations in other regions suggested that exogenous pollution and environmental induction strongly impacted the assembly of bacterial communities in the sediments. Several taxa that serve as intermediate centers in Co-occurrence network analysis (i.e., Pedosphaeraceae, Phycisphaeraceae, Anaerolineaceae, and Geobacteraceae) may play an important role in sediments. Furthermore, compared with previous studies of plants and animals, the results of our study suggest that various organisms, including microorganisms, are resistant to environmental changes and/or exogenous invasions, allowing them to maintain their community structure.

scholarly journals Reducing the Phytoplankton Biomass to Promote the Growth of Submerged Macrophytes by Introducing Artificial Aquatic Plants in Shallow Eutrophic Waters

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1370 ◽  
Author(s):  
Yue Wu ◽  
Licheng Huang ◽  
Yalin Wang ◽  
Lin Li ◽  
Genbao Li ◽  
...  
Keyword(s):  
Aquatic Plants ◽  
Bacterial Communities ◽  
Submerged Macrophytes ◽  
Cyanobacterial Blooms ◽  
Dianchi Lake ◽  
Effective Solution ◽  
Eutrophic Lakes ◽  
Planktonic Algae ◽  
Total Phosphorous ◽  
Harmful Cyanobacterial Blooms

Harmful cyanobacterial blooms frequently occur in shallow eutrophic lakes and usually cause the decline of submerged vegetation. Therefore, artificial aquatic plants (AAPs) were introduced into enclosures in the eutrophic Dianchi Lake to investigate whether or not they could reduce cyanobacterial blooms and promote the growth of submerged macrophytes. On the 60th day after the AAPs were installed, the turbidity, total nitrogen (TN), total phosphorous (TP), and the cell density of phytoplankton (especially cyanobacteria) of the treated enclosures were significantly reduced as compared with the control enclosures. The adsorption and absorption of the subsequently formed periphyton biofilms attached to the AAPs effectively decreased nutrient levels in the water. Moreover, the microbial diversity and structure in the water changed with the development of periphyton biofilms, showing that the dominant planktonic algae shifted from Cyanophyta to Chlorophyta. The biodiversity of both planktonic and attached bacterial communities in the periphyton biofilm also gradually increased with time, and were higher than those of the control enclosures. The transplanted submerged macrophyte (Elodea nuttallii) in treated enclosures recovered effectively and reached 50% coverage in one month while those in the control enclosures failed to grow. The application of AAPs with incubated periphyton presents an environmentally-friendly and effective solution for reducing nutrients and controlling the biomass of phytoplankton, thereby promoting the restoration of submerged macrophytes in shallow eutrophic waters.

scholarly journals Organic carbon mass accumulation rate regulates the flux of reduced substances from the sediments of deep lakes

2017 ◽  
Author(s):  
Thomas Steinsberger ◽  
Martin Schmid ◽  
Alfred Wüest ◽  
Robert Schwefel ◽  
Bernhard Wehrli ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Accumulation Rate ◽  
Eutrophic Lake ◽  
Data Sets ◽  
Deep Lakes ◽  
Eutrophic Lakes ◽  
Mass Accumulation Rate ◽  
Carbon Mass ◽  
Major Factors ◽  
Mass Accumulation

Abstract. The flux of reduced substances from the sediment to the bottom water (Fred) is one of the major factors contributing to the consumption of oxygen in the hypolimnia of lakes and thus crucial for lake oxygen management. This study presents sediment porewater measurements at different water depths from five deep lakes of differing trophic states. Fred was directly proportional to the total organic carbon mass accumulation rate (TOC-MAR) measured in the sediments. In eutrophic lakes Fred decreased systematically with increasing mean hypolimnion depth (zH). In Lake Baldegg, both TOC-MAR and Fred increased with depth due to sediment focusing. Temporarily anoxic conditions increased Fred even in the oligotrophic Lake Aegeri, while Fred was surprisingly low in the 310 m deep but eutrophic Lake Geneva. As TOC-MAR and zH are based on more commonly available data sets, these relationships provide an estimate for the O2 consumption by Fred, where no direct flux measurements are available.

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