Spatio-temporal connectivity of a toxic cyanobacterial community and its associated microbiome along a freshwater-marine continuum

Harmful Algae, Journal Year: 2024, Volume and Issue: 134, P. 102627 - 102627

Published: April 1, 2024

Due to climate changes and eutrophication, blooms of predominantly toxic freshwater cyanobacteria are intensifying likely colonize estuaries, thus impacting benthic organisms shellfish farming representing a major ecological, health economic risk. In the natural environment, Microcystis form large mucilaginous colonies that influence development both cyanobacterial embedded bacterial communities. However, little is known about fate by salinity increase. this study, we monitored dominated bloom its microbiome along French freshwater-marine gradient at different phases bloom. We demonstrated in genotypic composition, production specific metabolites (toxins compatible solutes) heterotrophic bacteria structure response particular M. aeruginosa wesenbergii survived salinities up 20. Based on microcystin gene abundance, became more during their estuarine transfer but with no selection variants. An increase solutes occurred continuum extensive trehalose betaine accumulations. Salinity structured most community, an increased richness diversity continuum. A core mucilage-associated attached fraction was highly abundant suggesting strong interaction between protecting role mucilage against osmotic shock. These results underline need better determine interactions as key widespread success adaptation various environmental conditions.

Language: Английский

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Cyanobacterial Algal Bloom Monitoring: Molecular Methods and Technologies for Freshwater Ecosystems

Microorganisms, Journal Year: 2023, Volume and Issue: 11(4), P. 851 - 851

Published: March 27, 2023

Cyanobacteria (blue-green algae) can accumulate to form harmful algal blooms (HABs) on the surface of freshwater ecosystems under eutrophic conditions. Extensive HAB events threaten local wildlife, public health, and utilization recreational waters. For detection/quantification cyanobacteria cyanotoxins, both United States Environmental Protection Agency (USEPA) Health Canada increasingly indicate that molecular methods be useful. However, each detection method has specific advantages limitations for monitoring HABs in water ecosystems. Rapidly developing modern technologies, including satellite imaging, biosensors, machine learning/artificial intelligence, integrated with standard/conventional overcome associated traditional cyanobacterial methodology. We examine advances cell lysis methodology conventional/modern methods, imaging techniques, polymerase chain reaction (PCR)/DNA sequencing, enzyme-linked immunosorbent assays (ELISA), mass spectrometry, remote sensing, learning/AI-based prediction models. This review focuses specifically methodologies likely employed ecosystems, especially Great Lakes region North America.

Language: Английский

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Identification of potential microbial risk factors associated with fecal indicator exceedances at recreational beaches

Environmental Microbiome, Journal Year: 2024, Volume and Issue: 19(1)

Published: Jan. 15, 2024

Abstract Background Fecal bacterial densities are proxy indicators of beach water quality, and posting decisions made based on Beach Action Value (BAV) exceedances for a beach. However, these traditional monitoring methods do not reflect the full extent microbial quality changes associated with BAV at recreational beaches (including harmful cyanobacteria). This proof concept study evaluates potential metagenomics comprehensively assessing community compared to non-exceedances two urban their adjacent river sources. Results Compared non-exceedance samples, exceedance samples exhibited higher alpha diversity (diversity within sample) that could be further differentiated into separate clusters (Beta-diversity). For A, Cyanobacterial sequences (resolved as Microcystis Pseudanabaena genus level) were significantly more abundant in samples. qPCR validation supported abundance results from metagenomic analysis also identified saxitoxin genes 50% sp gene days (when fecal indicator data indicated should open purposes). days, Fibrobacteres, Pseudomonas , Acinetobacter, Clostridium (and positively correlated densities) A. B, Spirochaetes Leptospira Burkholderia Vibrio Similar trends observed sources beaches. Antibiotic Resistance Genes (ARGs) consistently detected both we did observe significant difference or correlation ARGs between Conclusion provides comprehensive freshwater While there increases some taxa human health concern increased (e.g. ), analyses other ) lower days. can help develop targeted strategies beach-specific risk management approaches.

Language: Английский

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Temporal and Depth‐Driven Variability of Pelagic Bacterial Communities in Lake Erie: Biofilm and Plankton Dynamics

Environmental Microbiology Reports, Journal Year: 2025, Volume and Issue: 17(2)

Published: March 21, 2025

Despite constituting an important component of freshwater ecosystems, biofilm assemblages have remained relatively understudied compared to plankton, especially in systems such as the western basin Lake Erie (WBLE). This study therefore aimed elucidate temporal and vertical shifts microbial communities planktonic growth on artificial substrates WBLE water column at discrete depths, investigating overlap shared taxa between community types. Sequencing 16S rRNA gene revealed concurrent biofilm-plankton samples a low percentage (~10%) amplicon sequence variants (ASVs) indicating distinct free-living substrate-attached bacteria. Plankton did not significantly differ surface bottom depths (1 8 m), whereas differed upper (1-4 m) lower (5-8 columns. Temporal variation composition was observed biofilm, with early periods (June-July) showing significant dissimilarity followed by compositional convergence late summer onwards (August-October). With expansion infrastructure aquatic systems, there is novel substrate material observe spatiotemporal patterns colonisation throughout pelagic zone. These results demonstrate complexity bacterial from plankton freshwater, providing insight into assembly through succession across depth.

Language: Английский

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Hydrological connectivity shape the nitrogen pollution sources and microbial community structure in a river-lake connected system

Frontiers in Microbiology, Journal Year: 2025, Volume and Issue: 16

Published: April 11, 2025

Intensified agricultural and urban activities have exacerbated nitrogen pollution, posing a severe threat to freshwater ecosystems, particularly under intensified urbanization activities. This study systematically examined Baiyangdian Lake (BYD) its principal inflowing rivers, namely Fu River (FH), Baigouyin (BGY), Xiaoyi (XY) characterize the spatio-temporal distribution, primary sources, impact on sediment microbial community structure. Results indicated pronounced seasonal variations in both pollution loads with riverine levels rising markedly from dry season (May) wet (August). Atmospheric deposition accounted for 43.9% of input season, whereas fertilizers sewage contributed 23.3 26.4%, respectively. Additionally, communities exhibited distinct temporal spatial patterns, significantly higher diversity species richness being during season. The, composition shifted, as evidenced by decline Proteobacteria increases Firmicutes Actinobacteriota . River-lake connectivity emerged critical factor, FH displaying notably index compared BGY XY rivers. Structural equation modeling (SEM) analysis further revealed that river-lake was positively correlated negatively α-diversity. These findings demonstrated directly influenced concentrations, which turn indirectly modulated diversity.

Language: Английский

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Algae in Recreational Waters: An Overview within a One Health Perspective

Water, Journal Year: 2024, Volume and Issue: 16(7), P. 946 - 946

Published: March 25, 2024

Recreational water activities are widely recognized to have a positive impact on our physical and mental well-being. However, recreational sources their management also risk factor for human health due different agents, including the overgrowth of cyanobacteria algae. The presence algae in waters represents One Health threat because potential release overuse biocides. These organisms metabolize organic matter produce thermophilic thermotolerant toxins. Moreover, species involved biofilm formation processes, thus impacting quality safety posing risks environment animal health. Different participate an managing equipment maintenance. By searching literature databases, e.g., PubMed, we reviewed state art, providing basic definitions, taxonomy, epidemiological or medical issues related uses water. Methods treatments monitoring were summarized, considering both traditional innovative strategies. Public surveillance approaches focus detection toxins, biofilms, understanding benthonic planktonic components as part larger microbial biodiversity. review process allowed us acknowledge that this is first comprehensive overview carried out within wider outlook.

Language: Английский

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Unraveling the rate-limiting step in microorganisms' mediation of denitrification and phosphorus absorption/transport processes in a highly regulated river-lake system

Frontiers in Microbiology, Journal Year: 2023, Volume and Issue: 14

Published: Oct. 13, 2023

River-lake ecosystems are indispensable hubs for water transfers and flow regulation engineering, which have frequent complex artificial hydrological processes, the quality is often unstable. Microorganisms usually affect these systems by driving nutrient cycling process. Thus, understanding key biochemical rate-limiting steps under highly regulated conditions was critical stability of river-lake ecosystems. This study investigated how microorganisms genes involving nitrogen phosphorus contributed to combining 16S rRNA metagenomic sequencing using Dongping system as case study. The results showed that concentrations were significantly lower in lake zones than river inflow outflow (p < 0.05). Pseudomonas, Acinetobacter, Microbacterium associated with nitrate phosphate removal. These promote denitrification (nirB/narG/narH/nasA) absorption transport (pstA/pstB/pstC/pstS). Partial least squares path modeling (PLS-PM) revealed environmental factors (especially velocity COD concentration) a significant negative effect on microbial abundance 0.001). Our provides theoretical support effective management protection transfer function system.

Language: Английский

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Interplays between cyanobacterial blooms and antibiotic resistance genes

Environment International, Journal Year: 2023, Volume and Issue: 181, P. 108268 - 108268

Published: Oct. 18, 2023

Cyanobacterial harmful algal blooms (cyanoHABs), which are a form of microbial dysbiosis in freshwater environments, an emerging environmental and public health concern. Additionally, the environment serves as reservoir antibiotic resistance genes (ARGs), pose risk transmission during dysbiosis, such cyanoHABs. However, interactions between potential synergistic pollutants, cyanoHABs, ARGs remain poorly understood. During Microcystis high microcystin levels were dominant all nine regions river sampled. The resistome, mobilome, microbiome interrelated linked to physicochemical properties freshwater. Planktothrix Pseudanabaena competed with Actinobacteriota Proteobacteria Forty two ARG carriers identified, most belonged Proteobacteria. showed strong correlation density, decreased severity cyanoHAB. Although due reduction mobile gene elements (MGEs) virulence factors (VFs) increased. We explored relationship cyanoHABs for interaction. Our findings demonstrated that cyanobacteria compete commensal bacteria Proteobacteria, carry freshwater, resulting levels. Moreover, generate biotic abiotic stress microbiome, may lead increase MGEs VFs. Exploration intricate interplays pathobiome not only revealed mechanisms underlying dynamics but also emphasizes need prioritize prevention management ARGs.

Language: Английский

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Dynamics of the benthic and planktic microbiomes in a Planktothrix-dominated toxic cyanobacterial bloom in Australia

Water Research, Journal Year: 2023, Volume and Issue: 249, P. 120980 - 120980

Published: Dec. 5, 2023

Cyanobacterial blooms are a concerning issue that threaten ecosystems, ecology and animal health. Bloom frequency has increased tremendously in recent times due to pollution, eutrophication of waterways, climate change, changes microbial community dynamics within the aquatic environment. Information about spatiotemporal variation communities drive cyanobacterial bloom is very limited. Here, we analysed diversity composition bacterial communities, with focus on cyanobacteria, during phase natural reservoir Eastern Australia using high throughput amplicon sequencing. Sampling points season had no influence richness evenness period, however some compositional differences were apparent across seasons. Cyanobacteria highly abundant summer autumn compared winter spring. The dominant taxa Planktothrix, Cyanobium Microcystis found be significantly autumn. While abundance soared (25.4%), dominated by Planktothrix (12.2%) (8.0%), was highest (24.9%) consisted (7.8%), Nodularia (5.3%), Planktothricoides (4.6%), (3.5%), (2.3%). strongly correlated non-photosynthetic Gastranaerophilales sediment water, suggested vertical transmission from gut through faeces. To our knowledge, this first report Planktothrix-driven toxic Australia. Our study expands current understanding sheds light setting future management strategies for its control.

Language: Английский

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Environmental drivers of phytoplankton community dynamics in an agriculturally-influenced tributary in the lower Great Lakes

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 939, P. 173411 - 173411

Published: May 23, 2024

Phytoplankton community composition in tributaries differs from that their receiving waters, due to light limitation suspended particles and other factors such as nutrient availability temperature. This study was designed manipulate levels early, mid, late summer determine the combined effects of attenuation naturally varying on phytoplankton an agriculturally-influenced tributary lower Great Lakes. In all trials, situ microcosm experiments show abundance increased under three treatments (60 %, 75 85 % attenuation) relative time-zero, but higher reduced total controls. Highest diversity terms richness evenness occurred September (late summer), across trials lowest highest (85 %). followed a normal seasonal shift diatoms dominating June (early by cyanobacteria mid summer. general, (especially corresponded with dominance cyanobacteria. These findings support hypothesis vary promotes buoyant taxa more tolerant low levels.

Language: Английский

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