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Liu H, Du X, Zhang Z, Ge K, Chen X, Losiewicz MD, Guo H, Zhang H. Co-exposure of microcystin and nitrite enhanced spermatogenic disorders: The role of mtROS-mediated pyroptosis and apoptosis. ENVIRONMENT INTERNATIONAL 2024; 188:108771. [PMID: 38805914 DOI: 10.1016/j.envint.2024.108771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 04/26/2024] [Accepted: 05/21/2024] [Indexed: 05/30/2024]
Abstract
Microcystins (MCs) and nitrites are coexisted in the environment and have reproductive toxicity. The combined toxic effect and mechanism of MCs and nitrite on spermatogenesis remain largely unclear. In the present study, co-exposure to microcystin-leucine arginine (MC-LR) and sodium nitrite (NaNO2) aggravated testicular damage of Balb/c mice and mitochondrial impairment of spermatogonia, Sertoli cells, and sperm. Furthermore, MC-LR and NaNO2 reduced sperm density with a synergistic effect. In addition, MC-LR and NaNO2 synergistically induced oxidative stress in the reproductive system by decreasing superoxide dismutase (SOD) activity and glutathione (GSH) levels and increasing levels of mitochondrial reactive oxygen species (mtROS) and reactive oxygen species (ROS). More importantly, mitoquidone mesylate (MitoQ), an inhibitor of mtROS, blocked MC-LR and NaNO2-induced spermatogonia and Sertoli cell apoptosis by inhibiting high expression of Bax, Fadd, Caspase-8, and cleaved-Caspase-3. On the other hand, MitoQ suppressed pyroptosis of Sertoli cells by inhibiting the expression of NLRP3, N-GSDMD, and cleaved-Caspase-1. Additionally, MitoQ alleviated co-exposure-induced sperm density reduction and organ index disorders in F1 generation mice. Together, co-exposure of MC-LR and NaNO2 can enhance spermatogenic disorders by mitochondrial oxidative impairment-mediated germ cell death. This study emphasizes the potential risks of MC-LR and NaNO2 on reproduction in realistic environments and highlights new insights into the cause and treatment of spermatogenic disorders.
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Affiliation(s)
- Haohao Liu
- College of Public Health, Zhengzhou University, Zhengzhou 450001, Henan, China; Department of Public Health, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450001, Henan, China
| | - Xingde Du
- College of Public Health, Zhengzhou University, Zhengzhou 450001, Henan, China
| | - Zongxin Zhang
- College of Public Health, Zhengzhou University, Zhengzhou 450001, Henan, China
| | - Kangfeng Ge
- College of Public Health, Zhengzhou University, Zhengzhou 450001, Henan, China
| | - Xinghai Chen
- Department of Chemistry and Biochemistry, St Mary's University, San Antonio, TX, USA
| | - Michael D Losiewicz
- Department of Chemistry and Biochemistry, St Mary's University, San Antonio, TX, USA
| | - Hongxiang Guo
- College of Life Sciences, Henan Agricultural University, Zhengzhou, 450002 Henan, China.
| | - Huizhen Zhang
- College of Public Health, Zhengzhou University, Zhengzhou 450001, Henan, China.
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Batool U, Tromas N, Simon DF, Sauvé S, Shapiro BJ, Ahmed M. Snapshot of cyanobacterial toxins in Pakistani freshwater bodies. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:24648-24661. [PMID: 38448773 DOI: 10.1007/s11356-024-32744-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 02/28/2024] [Indexed: 03/08/2024]
Abstract
Cyanobacteria are known to produce diverse secondary metabolites that are toxic to aquatic ecosystems and human health. However, data about the cyanotoxins occurrence and cyanobacterial diversity in Pakistan's drinking water reservoirs is scarce. In this study, we first investigated the presence of microcystin, saxitoxin, and anatoxin in 12 water bodies using an enzyme-linked immunosorbent assay (ELISA). The observed cyanotoxin values for the risk quotient (RQ) determined by ELISA indicated a potential risk for aquatic life and human health. Based on this result, we made a more in-depth investigation with a subset of water bodies (served as major public water sources) to analyze the cyanotoxins dynamics and identify potential producers. We therefore quantified the distribution of 17 cyanotoxins, including 12 microcystin congeners using a high-performance liquid chromatography-high-resolution tandem mass spectrometry/mass spectrometry (HPLC-HRMS/MS). Our results revealed for the first time the co-occurrence of multiple cyanotoxins and the presence of cylindrospermopsin in an artificial reservoir (Rawal Lake) and a semi-saline lake (Kallar Kahar). We also quantified several microcystin congeners in a river (Panjnad) with MC-LR and MC-RR being the most prevalent and abundant. To identify potential cyanotoxin producers, the composition of the cyanobacterial community was characterized by shotgun metagenomics sequencing. Despite the noticeable presence of cyanotoxins, Cyanobacteria were not abundant. Synechococcus was the most abundant cyanobacterial genus found followed by a small amount of Anabaena, Cyanobium, Microcystis, and Dolichospermum. Moreover, when we looked at the cyanotoxins genes coverage, we never found a complete microcystin mcy operon. To our knowledge, this is the first snapshot sampling of water bodies in Pakistan. Our results would not only help to understand the geographical spread of cyanotoxin in Pakistan but would also help to improve cyanotoxin risk assessment strategies by screening a variety of cyanobacterial toxins and confirming that cyanotoxin quantification is not necessarily related to producer abundance.
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Affiliation(s)
- Uzma Batool
- Institute of Microbiology and Molecular Genetics, University of the Punjab, Lahore, Pakistan
- Department of Biological Sciences, Université de Montréal, Montreal, Canada
| | - Nicolas Tromas
- Department of Biological Sciences, Université de Montréal, Montreal, Canada.
- Department of Microbiology and Immunology, McGill University, Montreal, Canada.
| | - Dana F Simon
- Department of Chemistry, Université de Montréal, Montreal, Canada
| | - Sébastien Sauvé
- Department of Chemistry, Université de Montréal, Montreal, Canada
| | - B Jesse Shapiro
- Department of Microbiology and Immunology, McGill University, Montreal, Canada
| | - Mehboob Ahmed
- Institute of Microbiology and Molecular Genetics, University of the Punjab, Lahore, Pakistan
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3
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Xue Z, Xiong Z, Wei Z, Wang L, Xu M. Interactive Effects of Polyethylene Microplastics and Cadmium on Growth of Microcystis aeruginosa. TOXICS 2024; 12:254. [PMID: 38668477 PMCID: PMC11053517 DOI: 10.3390/toxics12040254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 03/26/2024] [Accepted: 03/26/2024] [Indexed: 04/29/2024]
Abstract
Polyethylene (PE) is a common component of microplastic pollution, and cadmium (Cd) is a prevalent pollutant in contaminated freshwater bodies in China. Among cyanobacteria, Microcystis aeruginosa (M. aeruginosa) plays a crucial role in the formation of algal blooms in these water systems. However, there has been limited research on how microplastics and heavy metals affect cyanobacteria ecologically. This study aimed to evaluate the physiological effects of individual and combined exposure to Cd pollutants and microplastics on M. aeruginosa. The solutions containing 13 µm and 6.5 µm PE particles (100 mg/L) with Cd were used in the research. The results indicated that the combined treatment led to a significant inhibition of chlorophyll a content, dropping to zero by day 5. The treated groups exhibited higher microcystins (MCs) content compared to the control group, suggesting increased MCs release due to pollutant exposure. Interestingly, the adsorption of heavy metals by microplastics partially alleviated the toxicity of heavy metals on algal cells. Moreover, the combined treatment significantly suppressed catalase (CAT) activity compared to Cd treatment, indicating a synergistic effect that led to greater oxidative stress. Overall, this study provides valuable insights into the impact of PE and Cd pollution on freshwater ecosystems, elucidates the physiological responses of cyanobacteria to these pollutants, and establishes a theoretical groundwork for addressing complex water pollution using cyanobacteria-based strategies.
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Affiliation(s)
- Zihan Xue
- Miami College, Jinming Campus, Henan University, Kaifeng 475004, China; (Z.X.); (Z.X.); (Z.W.)
| | - Zetao Xiong
- Miami College, Jinming Campus, Henan University, Kaifeng 475004, China; (Z.X.); (Z.X.); (Z.W.)
| | - Zhangdong Wei
- Miami College, Jinming Campus, Henan University, Kaifeng 475004, China; (Z.X.); (Z.X.); (Z.W.)
| | - Lin Wang
- Miami College, Jinming Campus, Henan University, Kaifeng 475004, China; (Z.X.); (Z.X.); (Z.W.)
- College of Geography and Environmental Science, Jinming Campus, Henan University, Kaifeng 475004, China
- Henan Key Laboratory of Earth System Observation and Modeling, Jinming Campus, Henan University, Kaifeng 475004, China
| | - Ming Xu
- College of Geography and Environmental Science, Jinming Campus, Henan University, Kaifeng 475004, China
- Henan Key Laboratory of Earth System Observation and Modeling, Jinming Campus, Henan University, Kaifeng 475004, China
- Guangdong-Hong Kong Joint Laboratory for Carbon Neutrality, Jiangmen Laboratory of Carbon Science and Technology, Jiangmen 529199, China
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4
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Liu F, Zhang H, Wang Y, Yu J, He Y, Wang D. Hysteresis analysis reveals how phytoplankton assemblage shifts with the nutrient dynamics during and between precipitation patterns. WATER RESEARCH 2024; 251:121099. [PMID: 38184914 DOI: 10.1016/j.watres.2023.121099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 12/29/2023] [Accepted: 12/31/2023] [Indexed: 01/09/2024]
Abstract
The escalation of global eutrophication has significantly increased due to the impact of climate change, particularly the increased frequency of extreme rainfall events. Predicting and managing eutrophication requires understanding the consequences of precipitation events on algal dynamics. Here, we assessed the influence of precipitation events throughout the year on nutrient and phytoplankton dynamics in a drinking water reservoir from January 2020 to January 2022. Four distinct precipitation patterns, namely early spring flood rain (THX), Plum rain (MY), Typhoon rain (TF), and Dry season (DS), were identified based on rainfall intensity, duration time, and cumulative rainfall. The study findings indicate that rainfall is the primary driver of algal dynamics by altering nutrient levels and TN:TP ratios during wet seasons, while water temperature becomes more critical during the Dry season. Combining precipitation characteristics with the lag periods between algal proliferation and rainfall occurrence is essential for accurately assessing the impact of rainfall on algal blooms. The highest algae proliferation occurred approximately 20 and 30 days after the peak rainfall during the MY and DS periods, respectively. This was influenced by the intensity and cumulative precipitation. The reservoir exhibited two distinct TN/TP ratio stages, with average values of 52 and 19, respectively. These stages were determined by various forms of nitrogen and phosphorus in rainfall-driven inflows and were associated with shifts from Bacillariophyta-dominated to Cyanophyta-dominated blooms during the MY and DS seasons. Our findings underscore the interconnected effects of nutrients, temperature, and hydrological conditions driven by diverse rainfall patterns in shaping algal dynamics. This study provides valuable insights into forecasting algal bloom risks in the context of climate change and developing sustainable strategies for lake or reservoir restoration.
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Affiliation(s)
- Fan Liu
- National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Environment, China University of Geoscience (Wuhan), Wuhan 430074, China
| | - Honggang Zhang
- National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Yangtze River Delta Branch, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Yiwu 322000, China.
| | - Yabo Wang
- College of Civil Engineering, Kashi University, Kashi 844008, China
| | - Jianwei Yu
- National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yi He
- Yangtze River Delta Branch, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Yiwu 322000, China
| | - Dongsheng Wang
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, Zhejiang, China
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5
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Peng P, Zhou L, Yilimulati M, Zhang S. Unleashing the power of acetylacetone: Effective control of harmful cyanobacterial blooms with ecological safety. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:168644. [PMID: 38000755 DOI: 10.1016/j.scitotenv.2023.168644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 11/12/2023] [Accepted: 11/15/2023] [Indexed: 11/26/2023]
Abstract
Harmful algal blooms resulting from eutrophication pose a severe threat to human health. Acetylacetone (AA) has emerged as a potential chemical for combatting cyanobacterial blooms, but its real-world application remains limited. In this study, we conducted a 42-day evaluation of AA's effectiveness in controlling blooms in river water, with a focus on the interplay between ecological community structure, organism functional traits, and water quality. At a concentration of 0.2 mM, AA effectively suppressed the growth of Cyanobacteria (88 %), Bacteroidia (49 %), and Alphaproteobacteria (52 %), while promoting the abundance of Gammaproteobacteria (5.0 times) and Actinobacteria (7.2 times) that are associated with the degradation of organic matter. Notably, after dosing of AA, the OD680 (0.07 ± 0.02) and turbidity (8.6 ± 2.1) remained at a satisfactory level. AA induced significant disruptions in two photosynthesis and two biosynthesis pathways (P < 0.05), while simultaneously enriching eight pathways of xenobiotics biodegradation and metabolism. This enrichment facilitated the reduction of organic pollutants and supported improved water quality. Importantly, AA treatment decreased the abundance of two macrolide-related antibiotic resistance genes (ARGs), ereA and vatE, while slightly increased the abundance of two aminoglycoside-related ARGs, aacA and strB. Overall, our findings establish AA as an efficient and durable algicide with favorable ecological safety. Moreover, this work contributes to the development of effective strategies for maintaining and restoring the health and resilience of aquatic ecosystems impacted by harmful algal blooms.
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Affiliation(s)
- Peng Peng
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Lang Zhou
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Mihebai Yilimulati
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Shujuan Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
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Maurer JA, Kim AM, Oblie N, Hefferan S, Xie H, Slitt A, Jenkins BD, Bertin MJ. Temporal Dynamics of Cyanobacterial Bloom Community Composition and Toxin Production from Urban Lakes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.07.579333. [PMID: 38370816 PMCID: PMC10871351 DOI: 10.1101/2024.02.07.579333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
With a long evolutionary history and a need to adapt to a changing environment, cyanobacteria in freshwater systems use specialized metabolites for communication, defense, and physiological processes. However, the role that these metabolites play in differentiating species, maintaining microbial communities, and generating niche persistence and expansion is poorly understood. Furthermore, many cyanobacterial specialized metabolites and toxins present significant human health concerns due to their liver toxicity and their potential impact to drinking water. Gaps in knowledge exist with respect to changes in species diversity and toxin production during a cyanobacterial bloom (cyanoHAB) event; addressing these gaps will improve understanding of impacts to public and ecological health. In the current project, we utilized a multiomics strategy (DNA metabarcoding and metabolomics) to determine the cyanobacterial community composition, toxin profile, and the specialized metabolite pool at three freshwater lakes in Providence, RI during summer-fall cyanoHABs. Species diversity decreased at all study sites over the course of the bloom event, and toxin production reached a maximum at the midpoint of the event. Additionally, LC-MS/MS-based molecular networking identified new toxin congeners. This work provokes intriguing questions with respect to the use of allelopathy by organisms in these systems and the presence of emerging toxic compounds that can impact public health.
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Affiliation(s)
- Julie A. Maurer
- Department of Cell and Molecular Biology, University of Rhode Island, Kingston, RI 02881, United States
| | - Andrew M. Kim
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, United States
| | - Nana Oblie
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, United States
| | - Sierra Hefferan
- Department of Cell and Molecular Biology, University of Rhode Island, Kingston, RI 02881, United States
| | - Hannuo Xie
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, United States
| | - Angela Slitt
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, United States
| | - Bethany D. Jenkins
- Department of Cell and Molecular Biology and Graduate School of Oceanography, University of Rhode Island, Kingston, RI 02881, United States
| | - Matthew J. Bertin
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, United States
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Zhang K, Gu Y, Cheng C, Xue Q, Xie L. Changes in microcystin concentration in Lake Taihu, 13 years (2007-2020) after the 2007 drinking water crisis. ENVIRONMENTAL RESEARCH 2024; 241:117597. [PMID: 37939808 DOI: 10.1016/j.envres.2023.117597] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 10/10/2023] [Accepted: 11/02/2023] [Indexed: 11/10/2023]
Abstract
Since the 2007 water crisis occurred in Lake Taihu, substantial measures have been taken to restore the lake. This study evaluates the effectiveness of these restoration activities. We examined the physicochemical parameters and the distribution of microcystin and Microcystis in both the water column and sediment during the bloom period of May 2020 to October 2020. The mean value of extracellular and intracellular microcystin content was 0.12 μg L-1 and 16.26 μg L-1, respectively. The mean value of microcystin in sediment was 172.02 ng g-1 and peaked in August. The concentration in the water and sediment was significantly lower than the historical average concentration. The abundance of toxigenic Microcystis and total Microcystis in the water column ranged from 2.61 × 102 to 2.25 × 109 copies·L-1 and 8.28 × 105 to 2.76 × 109 copies·L-1, respectively. The proportion of toxic Microcystis in the sediment ranging from 31.2% to 19.12%. The highest and lowest region was Meiliang Bay and Grass-algae type zone, respectively. The copy number of the 16S rRNA gene was 1-4 orders of magnitude higher than that of mcyA gene in populations of Microcystis, indicating that non-toxic Microcystis was the dominant form in the majority of the lake. The abundance of toxic Microcystis in the water column was positively correlated with total phosphorus, PO43--P and pH, while the water temperature played distinct role to the distribution of toxic Microcystis in sediment. Our research indicated phosphorus remains a key factor influencing the toxic Microcystis and microcystins in the water column. pH played distinct roles in the distribution of microcystins in sediment and water column. The increasing water temperature is a threat. Explicit management actions and policies, which take into account nutrient concentrations, pH, and increasing temperatures, are necessary to understand and control the distribution of microcystin and Microcystis in Lake Taihu.
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Affiliation(s)
- Kaiye Zhang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yurong Gu
- Kunshan Economic and Technological Development Zone Work Safety and Environmental Protection Bureau, Kunshan, 215300, China
| | - Chen Cheng
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qingju Xue
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
| | - Liqiang Xie
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China; School of Ecology and Environment, Anhui Normal University, Wuhu, Anhui, 241002, China.
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Pawlik-Skowrońska B, Bownik A, Pogorzelec M, Kulczycka J, Sumińska A. First report on adverse effects of cyanobacterial anabaenopeptins, aeruginosins, microginin and their mixtures with microcystin and cylindrospermopsin on aquatic plant physiology: An experimental approach. Toxicon 2023; 236:107333. [PMID: 37951248 DOI: 10.1016/j.toxicon.2023.107333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 10/12/2023] [Accepted: 11/01/2023] [Indexed: 11/13/2023]
Abstract
Cyanobacteria produce a variety of oligopeptides beyond microcystins and other metabolites. Their biological activities are not fully recognized especially to aquatic plants. Acute toxicity tests on Spirodela polyrhiza and Lemna minor exposed to a range of concentrations of cyanobacterial metabolites: anabaenopeptins (ANA-A, ANA-B), aeruginosins 98 (Aer-A, Aer-B), microginin-FR1 (MG-FR1), microcystin-LR (MC-LR) and cylindrospermopsin (Cyl) were carried out to compare their influence on plant physiology. Effects of their binary mixtures were determined by isobole approach and calculation of the combination index (CI) that indicates a type of metabolites' interaction. Cyclic oligopeptides microcystin-LR and anabaenopeptin-A revealed the strongest inhibition of S. polyrhiza growth while other metabolites appeared less toxic. Oxygen evolution was inhibited by Cyl, MC-LR, ANA-A, ANA-B, while both variants of aeruginosins and MG-FR1 did not affect this process. Photosynthetic pigments' contents decreased in S. polyrhiza exposed to ANA-A and Cyl, while MC-LR and Aer-A caused their slight increase. 96 h-EC50 values showed that the growth of L. minor was more sensitive to MC-LR, ANA-A, MG-FR1 and Cyl than the growth of S. polyrhiza. In S. polyrhiza synergistic effects of all the binary mixtures of peptides with MC-LR on oxygen evolution were observed, while antagonistic one on the growth of S. polyrhiza exposed to the mixtures with aeruginosins and ANA-A. The mixtures of MC-LR and MG-FR1 with cylindrospermopsin revealed synergistic effects on the growth but antagonistic one to the O2 evolution. Quadruple mixtures (ANA-A + MC-LR + MG-FR1+Cyl) did not reveal any inhibitive effect on the plant growth and very slight on the oxygen evolution, irrespectively of their total concentrations. Various effects caused by ANA-A and ANA-B suggest the importance of molecule structures of metabolites for toxicity. Composition of the mixtures of cyanobacterial metabolites was essential for the observed effects.
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Affiliation(s)
- Barbara Pawlik-Skowrońska
- Department of Hydrobiology and Protection of Ecosystems, Faculty of Environmental Biology, University of Life Sciences in Lublin, Dobrzanskiego 37, 20-262, Lublin, Poland.
| | - Adam Bownik
- Department of Hydrobiology and Protection of Ecosystems, Faculty of Environmental Biology, University of Life Sciences in Lublin, Dobrzanskiego 37, 20-262, Lublin, Poland
| | - Magdalena Pogorzelec
- Department of Hydrobiology and Protection of Ecosystems, Faculty of Environmental Biology, University of Life Sciences in Lublin, Dobrzanskiego 37, 20-262, Lublin, Poland
| | - Justyna Kulczycka
- Department of Hydrobiology and Protection of Ecosystems, Faculty of Environmental Biology, University of Life Sciences in Lublin, Dobrzanskiego 37, 20-262, Lublin, Poland
| | - Aleksandra Sumińska
- Department of Hydrobiology and Protection of Ecosystems, Faculty of Environmental Biology, University of Life Sciences in Lublin, Dobrzanskiego 37, 20-262, Lublin, Poland
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Muluye T, Fetahi T, Engdaw F, Mohammed A. Cyanotoxins in African waterbodies: occurrence, adverse effects, and potential risk to animal and human health. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2023; 45:7519-7542. [PMID: 37603139 DOI: 10.1007/s10653-023-01724-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 08/03/2023] [Indexed: 08/22/2023]
Abstract
Public concerns about cyanotoxins production in water and its detrimental impacts on human and animal health are growing primarily due to the widespread eutrophication observed in aquatic ecosystems. A review of relevant literature was done to determine the degree of cyanotoxin occurrence and its harmful effects in African waterbodies. Data were extracted from 64 published studies from 1990 to 2022 that quantified the concentration of cyanotoxins in African aquatic ecosystems. Cyanotoxins have been reported in 95 waterbodies (29 lakes, 41 reservoirs, 10 ponds, 9 rivers, 5 coastal waters, and 1 irrigation canal) from 15 African countries. Cyanotoxins were documented in all the regions of Africa except the central region. Microcystins have been reported in nearly all waterbodies (98.9%), but anatoxin-a (5.3%), cylindrospermopsin (2.1%), nodularins (2.1%), homoanatoxin-a (1.1%), and β-N-methylamino-L-alanine (1.1%) were encountered in a small number of water ecosystems, homoanatoxin-a and β-N-methylamino-L-alanine each occurred in one waterbody. The largest concentrations of microcystins and nodularins were reported in South African Lakes Nhlanganzwani (49,410 μg L-1) and Zeekoevlei (347,000 μg g-1). Microcystin concentrations exceeding the WHO guideline for lifetime drinking water (1 μg L-1) were reported in 63% of the aquatic ecosystems surveyed. The most frequently reported toxin-producing cyanobacteria genus is Microcystis spp. (73.7%), followed by Oscillatoria spp. (35.8%) and Dolichospermum spp. (33.7%). Cyanotoxin-related animal mortality and human illness were reported in the continent. Consequently, it is necessary to regularly monitor the level of nutrients, cyanobacteria, and cyanotoxins in African waterbodies in an integrated manner to devise a sustainable water resources management.
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Affiliation(s)
- Tesfaye Muluye
- Africa Centre of Excellence for Water Management, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia.
| | - Tadesse Fetahi
- Department of Zoological Sciences, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
| | - Flipos Engdaw
- Africa Centre of Excellence for Water Management, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
| | - Adem Mohammed
- Africa Centre of Excellence for Water Management, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
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Li H, Bhattarai B, Barber M, Goel R. Stringent Response of Cyanobacteria and Other Bacterioplankton during Different Stages of a Harmful Cyanobacterial Bloom. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:16016-16032. [PMID: 37819800 DOI: 10.1021/acs.est.3c03114] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
We conducted a field study to investigate the role of stringent response in cyanobacteria and coexisting bacterioplankton during nutrient-deprived periods at various stages of bloom in a freshwater lake (Utah Lake) for the first time. Using metagenomics and metatranscriptomics analyses, we examined the cyanobacterial ecology and expression of important functional genes related to stringent response, N and P metabolism, and regulation. Our findings mark a significant advancement in understanding the mechanisms by which toxic cyanobacteria survive and proliferate during nitrogen (N) and phosphorus (P) limitations. We successfully identified and analyzed the metagenome-assembled genomes (MAGs) of the dominant bloom-forming cyanobacteria, namely, Dolichospermum circinale, Aphanizomenon flos-aquae UKL13-PB, Planktothrix agardhii, and Microcystis aeruginosa. By mapping RNA-seq data to the coding sequences of the MAGs, we observed that these four prevalent cyanobacteria species activated multiple functions to adapt to the depletion of inorganic nutrients. During and after the blooms, the four dominant cyanobacteria species expressed high levels of transcripts related to toxin production, such as microcystins (mcy), anatoxins (ana), and cylindrospermopsins (cyr). Additionally, genes associated with polyphosphate (poly-P) storage and the stringent response alarmone (p)ppGpp synthesis/hydrolysis, including ppk, relA, and spoT, were highly activated in both cyanobacteria and bacterioplankton. Under N deficiency, the main N pathways shifted from denitrification and dissimilatory nitrate reduction in bacterioplankton toward N2-fixing and assimilatory nitrate reduction in certain cyanobacteria with a corresponding shift in the community composition. P deprivation triggered a stringent response mediated by spoT-dependent (p)ppGpp accumulation and activation of the Pho regulon in both cyanobacteria and bacterioplankton, facilitating inorganic and organic P uptake. The dominant cyanobacterial MAGs exhibited the presence of multiple alkaline phosphatase (APase) transcripts (e.g., phoA in Dolichospermum, phoX in Planktothrix, and Microcystis), suggesting their ability to synthesize and release APase enzymes to convert ambient organic P into bioavailable forms. Conversely, transcripts associated with bacterioplankton-dominated pathways like denitrification were low and did not align with the occurrence of intense cyanoHABs. The strong correlations observed among N, P, stringent response metabolisms and the succession of blooms caused by dominant cyanobacterial species provide evidence that the stringent response, induced by nutrient limitation, may activate unique N and P functions in toxin-producing cyanobacteria, thereby sustaining cyanoHABs.
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Affiliation(s)
- Hanyan Li
- Institute for Environmental Genomics, The University of Oklahoma, 101 David L Boren Blvd, Norman, Oklahoma 73019, United States
| | - Bishav Bhattarai
- Department of Civil and Environmental Engineering, The University of Utah, 110 S Central Campus, Salt Lake City, Utah 84112, United States
| | - Michael Barber
- Department of Civil and Environmental Engineering, The University of Utah, 110 S Central Campus, Salt Lake City, Utah 84112, United States
| | - Ramesh Goel
- Department of Civil and Environmental Engineering, The University of Utah, 110 S Central Campus, Salt Lake City, Utah 84112, United States
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Wang C. Regulating phytoplankton-available suspended particulate phosphorus (P) to control internal P pollution in lake: Conclusion from a short review. CHEMOSPHERE 2023; 331:138833. [PMID: 37137394 DOI: 10.1016/j.chemosphere.2023.138833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 04/20/2023] [Accepted: 04/30/2023] [Indexed: 05/05/2023]
Abstract
The necessity on controlling internal P pollution has been widely reported for lake restoration; thus far, cutting the migrations of soluble P from sediment to overlying water, especially under anoxic condition, is the main target of the internal P pollution control to achieve favorable ecological responses in lake. Here, according to the types of P directly available by phytoplankton, phytoplankton-available suspended particulate P (SPP) pollution, which mainly occurs under aerobic condition and due to sediment resuspension and soluble P adsorption by suspended particle, is found to be the other kind of internal P pollution. The SPP has long been a key index for environmental quality assessment, which could be indirectly reflected by the developed various methods for phytoplankton-available P pool analysis; also, the P has been demonstrated to be a major cause of phytoplankton breeding, typically in shallow lakes. Importantly, compared to the soluble P, SPP pollution clearly has more complicated loading pathways and P activation mechanisms and involves in different fractions of P, even part of which are with relatively high stability in sediment and suspended particle, leading to the potential control measures for the pollution being more complex. Considering the potential differences of internal P pollution among various lakes, this study is therefore calling for more research to focus on regulating phytoplankton-available SPP pollution. Recommendations are also offered to bridge knowledge gap of the regulation to design proper measures for lake restoration.
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Affiliation(s)
- Changhui Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China.
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12
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Nwankwegu AS, Zhang L, Xie D, Ohore OE, Li Y, Yang G, Yao X, Song Z, Yang Q. Metabolites dynamics exacerbated by external nutrients inputs into a Ceratium hirundinella-dominated bloom in the Pengxi River, Three Gorges Reservoir, China. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2023; 258:106507. [PMID: 36965430 DOI: 10.1016/j.aquatox.2023.106507] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 03/20/2023] [Accepted: 03/21/2023] [Indexed: 06/18/2023]
Abstract
Secondary metabolites (toxins) production during harmful algal blooms (HABs) further increases the public health risks associated with water quality deterioration from anthropogenic eutrophication. In the present study, the dynamic pattern in the production of metabolites under different nutrient conditions in Ceratium-dominated spring HABs was investigated in Pengxi River, China. Results revealed five (5) important toxins all attributable to the Dinophyceae including azaspiracid 2&4, okadaic acid, tetrodotoxin, brevetoxin, and saxitoxin, each exhibiting certain levels of specificity to the ecosystem enrichments. In effect, while the production of azaspiracid 2 and okadaic acid was N-driven, azaspiracid 4 and tetrodotoxin were enhanced by Ca enrichment. The ambient HABs community structure shows absolute ecosystem dominance by a dinoflagellate, Ceratium hirundinella with relative abundance ((RA = 78.81%, p ˂ 0.05). However, P enrichment triggered a slight shift (p ≥ 0.05) in the HABs species structure within the cyanobacteria strictly represented by Chroococcus minor (RA = 26.60%) and Dolichospermum circinalis (RA = 23.91%) initiating possible emergency dominance. The effect of nutrient addition on biomass production as chlorophyll-a (Chl-a) confirmed a P-limited ecosystem juxtaposed by a secondary limitation by Ca. The significant stimulation on biomass as Chl-a from day 3 through day 4 by N and the multiple enrichments designated as NPFeCa was attributed to luxury consumption rather than limitation following N repletion thus delaying biomass accumulation. The study, therefore, offers useful insights into the dynamic pattern of toxins during spring HABs while it also provides comprehensive knowledge of the HABs impact predictions in the TGR.
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Affiliation(s)
- Amechi S Nwankwegu
- College of Resources and Environment, Southwest University, 1 Tiansheng Road, Beibei District, Chongqing 400716 China; National Base of International S&T Collaboration on Water Environmental Monitoring and Simulation in Three Gorges Reservoir Region, Chongqing 400716 China; College of Environment, Hohai University, No. 1 Xikang Road, Gulou District, Nanjing 210098, China
| | - Lei Zhang
- College of Resources and Environment, Southwest University, 1 Tiansheng Road, Beibei District, Chongqing 400716 China; National Base of International S&T Collaboration on Water Environmental Monitoring and Simulation in Three Gorges Reservoir Region, Chongqing 400716 China.
| | - Deti Xie
- College of Resources and Environment, Southwest University, 1 Tiansheng Road, Beibei District, Chongqing 400716 China; National Base of International S&T Collaboration on Water Environmental Monitoring and Simulation in Three Gorges Reservoir Region, Chongqing 400716 China.
| | - Okugbe E Ohore
- Institute of Marine Sciences, Shantou University, Shantou 515063, China
| | - Yiping Li
- College of Environment, Hohai University, No. 1 Xikang Road, Gulou District, Nanjing 210098, China
| | - Guanglang Yang
- College of Resources and Environment, Southwest University, 1 Tiansheng Road, Beibei District, Chongqing 400716 China
| | - Xuexing Yao
- College of Resources and Environment, Southwest University, 1 Tiansheng Road, Beibei District, Chongqing 400716 China
| | - Zenghui Song
- College of Resources and Environment, Southwest University, 1 Tiansheng Road, Beibei District, Chongqing 400716 China
| | - Qing Yang
- College of Resources and Environment, Southwest University, 1 Tiansheng Road, Beibei District, Chongqing 400716 China
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Belykh OI, Sorokovikova EG, Tomberg IV, Fedorova GA, Kuzmin AV, Krasnopeev AY, Suslova MY, Potapov SA, Belykh TI, Norovsuren J, Galachyants AD, Tikhonova IV. Water Quality, Toxicity and Diversity of Planktonic and Benthic Cyanobacteria in Pristine Ancient Lake Khubsugul (Hövsgöl), Mongolia. Toxins (Basel) 2023; 15:toxins15030213. [PMID: 36977104 PMCID: PMC10053237 DOI: 10.3390/toxins15030213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/07/2023] [Accepted: 03/08/2023] [Indexed: 03/16/2023] Open
Abstract
For the first time, microcystin-producing cyanobacteria have been detected in Khubsugul, which is ancient, pristine and one of the world’s largest lakes. The microcystin synthetase genes belonged to the genera Nostoc, Microcystis and possibly Snowella spp. No microcystins were found in the water of the lake. Using the HPLC-HRMS/TOF, five microcystin congeners were identified in biofilms from stony substrates sampled in the coastal zone. The concentration of microcystins in biofilms was low: 41.95 µg g−1 d. wt. by ELISA and 55.8 µg g−1 d. wt. using HPLC. The taxonomic composition of planktonic and benthic cyanobacterial communities was determined by means of microscopy and high-throughput sequencing of 16S rDNA amplicons. Nostocales cyanobacteria dominated benthos of Lake Khubsugul and Synechococcales—plankton. The abundance of cyanobacteria was low both in plankton and benthos; there was no mass development of cyanobacteria. Hydrochemical and microbiological analyses showed that the water in the lake was clean; the number of faecal microorganisms was significantly below the acceptable guideline values. Hydrochemical and hydrophysical parameters, and the concentration of chlorophyll a, were low and within the range of values recorded in the 1970s to 1990s, and corresponded to the oligotrophic state of the lake. There were no signs of anthropogenic eutrophication of the lake and no conditions for the cyanobacterial blooms.
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Affiliation(s)
- Olga I. Belykh
- Limnological Institute of the Siberian Branch of the Russian Academy of Sciences, 3 Ulan-Batorskaya Str., Irkutsk 664033, Russia
- Correspondence: (O.I.B.); (E.G.S.)
| | - Ekaterina G. Sorokovikova
- Limnological Institute of the Siberian Branch of the Russian Academy of Sciences, 3 Ulan-Batorskaya Str., Irkutsk 664033, Russia
- Correspondence: (O.I.B.); (E.G.S.)
| | - Irina V. Tomberg
- Limnological Institute of the Siberian Branch of the Russian Academy of Sciences, 3 Ulan-Batorskaya Str., Irkutsk 664033, Russia
| | - Galina A. Fedorova
- Limnological Institute of the Siberian Branch of the Russian Academy of Sciences, 3 Ulan-Batorskaya Str., Irkutsk 664033, Russia
| | - Anton V. Kuzmin
- Limnological Institute of the Siberian Branch of the Russian Academy of Sciences, 3 Ulan-Batorskaya Str., Irkutsk 664033, Russia
| | - Andrey Yu. Krasnopeev
- Limnological Institute of the Siberian Branch of the Russian Academy of Sciences, 3 Ulan-Batorskaya Str., Irkutsk 664033, Russia
| | - Maria Yu. Suslova
- Limnological Institute of the Siberian Branch of the Russian Academy of Sciences, 3 Ulan-Batorskaya Str., Irkutsk 664033, Russia
| | - Sergey A. Potapov
- Limnological Institute of the Siberian Branch of the Russian Academy of Sciences, 3 Ulan-Batorskaya Str., Irkutsk 664033, Russia
| | - Tatiana I. Belykh
- Institute for Culture, Social Communication and Information Technology, Baikal State University, 11 Lenin Str., Irkutsk 664003, Russia
| | - Jadambaa Norovsuren
- Institute of Biology of the Mongolian Academy of Sciences, 54B Peace Avenue, Bayanzurkh District, Ulaanbaatar 13330, Mongolia
| | - Agnia D. Galachyants
- Limnological Institute of the Siberian Branch of the Russian Academy of Sciences, 3 Ulan-Batorskaya Str., Irkutsk 664033, Russia
| | - Irina V. Tikhonova
- Limnological Institute of the Siberian Branch of the Russian Academy of Sciences, 3 Ulan-Batorskaya Str., Irkutsk 664033, Russia
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14
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Peng K, Jiao Y, Gao J, Xiong W, Zhao Y, Yang S, Liao M. Viruses may facilitate the cyanobacterial blooming during summer bloom succession in Xiangxi Bay of Three Gorges Reservoir, China. Front Microbiol 2023; 14:1112590. [PMID: 36970686 PMCID: PMC10030618 DOI: 10.3389/fmicb.2023.1112590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 02/13/2023] [Indexed: 03/11/2023] Open
Abstract
The occurrence of cyanobacterial blooms in summer are frequently accompanied by the succession of phytoplankton communities in freshwater. However, little is known regarding the roles of viruses in the succession, such as in huge reservoirs. Here, we investigated the viral infection characteristics of phytoplankton and bacterioplankton during the summer bloom succession in Xiangxi Bay of Three Gorges Reservoir, China. The results indicated that three distinct bloom stages and two successions were observed. From cyanobacteria and diatom codominance to cyanobacteria dominance, the first succession involved different phyla and led to a Microcystis bloom. From Microcystis dominance to Microcystis and Anabaena codominance, the second succession was different Cyanophyta genera and resulted in the persistence of cyanobacterial bloom. The structural equation model (SEM) showed that the virus had positive influence on the phytoplankton community. Through the Spearman’s correlation and redundancy analysis (RDA), we speculated that both the increase of viral lysis in the eukaryotic community and the increase of lysogeny in cyanobacteria may contributed to the first succession and Microcystis blooms. In addition, the nutrients supplied by the lysis of bacterioplankton might benefit the second succession of different cyanobacterial genera and sustain the dominance of cyanobacteria. Based on hierarchical partitioning method, the viral variables still have a marked effect on the dynamics of phytoplankton community, although the environmental attributes were the major factors. Our findings suggested that viruses played multiple potential roles in summer bloom succession and may help the blooms success of cyanobacteria in Xiangxi Bay. Under the background of increasingly serious cyanobacterial blooms worldwide, our study may have great ecological and environmental significance for understanding the population succession in phytoplankton and controlling the cyanobacterial blooms.
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Affiliation(s)
- Kaida Peng
- School of Life Sciences, Central China Normal University, Wuhan, Hubei, China
- Hubei Key Laboratory of Ecological Restoration for River-Lakes and Algal Utilization, School of Civil and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, China
| | - Yiying Jiao
- Hubei Key Laboratory of Ecological Restoration for River-Lakes and Algal Utilization, School of Civil and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, China
| | - Jian Gao
- Hubei Key Laboratory of Ecological Restoration for River-Lakes and Algal Utilization, School of Civil and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, China
| | - Wen Xiong
- Hubei Key Laboratory of Ecological Restoration for River-Lakes and Algal Utilization, School of Civil and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, China
| | - Yijun Zhao
- Hubei Key Laboratory of Ecological Restoration for River-Lakes and Algal Utilization, School of Civil and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, China
| | - Shao Yang
- School of Life Sciences, Central China Normal University, Wuhan, Hubei, China
| | - Mingjun Liao
- Hubei Key Laboratory of Ecological Restoration for River-Lakes and Algal Utilization, School of Civil and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, China
- *Correspondence: Mingjun Liao,
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15
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Zhou Z, Liu Y, Wang S, Xiao J, Cao X, Zhou Y, Song C. Interactions between Phosphorus Enrichment and Nitrification Accelerate Relative Nitrogen Deficiency during Cyanobacterial Blooms in a Large Shallow Eutrophic Lake. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:2992-3001. [PMID: 36753734 DOI: 10.1021/acs.est.2c07599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Regime shifts between nitrogen (N) and phosphorus (P) limitation, which trigger cyanobacterial succession, occur in shallow eutrophic lakes seasonally. However, the underlying mechanism is not yet fully illustrated. We provide a novel insight to address this from interactions between sediment P and nitrification through monthly field investigations including 204 samples and microcosm experiments in Lake Chaohu. Total N to P mass ratios (TN/TP) varied significantly across seasons especially during algal bloom in summer, with the average value being 26.1 in June and descending to 7.8 in September gradually, triggering dominant cyanobacterial succession from Microcystis to Dolichospermum. The regulation effect of sediment N/P on water column TN/TP was stronger in summer than in other seasons. Iron-bound P and alkaline phosphatase activity in sediment, rather than ammonium, contributed to the higher part of nitrification. Furthermore, our microcosm experiments confirmed that soluble active P and enzymatic hydrolysis of organic P, accumulating during algal bloom, fueled nitrifiers and nitrification in sediments. These processes promoted lake N removal and led to relative N deficiency in turn. Our results highlight that N and P cycles do not exist independently but rather interact with each other during lake eutrophication, supporting the dual N and P reduction program to mitigate eutrophication in shallow eutrophic lakes.
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Affiliation(s)
- Zijun Zhou
- Institute of Yellow River Water Resources Protection, Zhengzhou 450004, PR China
| | - Yuqian Liu
- Institute of Yellow River Water Resources Protection, Zhengzhou 450004, PR China
| | - Siyang Wang
- School of Water Resources and Hydropower Engineering, Wuhan University, Wuhan 430070, PR China
| | - Jian Xiao
- School of Environmental and Chemical Engineering, Jiangsu Ocean University, Lianyungang 222005, PR China
| | - Xiuyun Cao
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China
| | - Yiyong Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China
| | - Chunlei Song
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China
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16
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Linz DM, Sienkiewicz N, Struewing I, Stelzer EA, Graham JL, Lu J. Metagenomic mapping of cyanobacteria and potential cyanotoxin producing taxa in large rivers of the United States. Sci Rep 2023; 13:2806. [PMID: 36797305 PMCID: PMC9935515 DOI: 10.1038/s41598-023-29037-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 01/30/2023] [Indexed: 02/18/2023] Open
Abstract
Cyanobacteria and cyanotoxin producing cyanobacterial blooms are a trending focus of current research. Many studies focus on bloom events in lentic environments such as lakes or ponds. Comparatively few studies have explored lotic environments and fewer still have examined the cyanobacterial communities and potential cyanotoxin producers during ambient, non-bloom conditions. Here we used a metagenomics-based approach to profile non-bloom microbial communities and cyanobacteria in 12 major U.S. rivers at multiple time points during the summer months of 2019. Our data show that U.S. rivers possess microbial communities that are taxonomically rich, yet largely consistent across geographic location and time. Within these communities, cyanobacteria often comprise significant portions and frequently include multiple species with known cyanotoxin producing strains. We further characterized these potential cyanotoxin producing taxa by deep sequencing amplicons of the microcystin E (mcyE) gene. We found that rivers containing the highest levels of potential cyanotoxin producing cyanobacteria consistently possess taxa with the genetic potential for cyanotoxin production and that, among these taxa, the predominant genus of origin for the mcyE gene is Microcystis. Combined, these data provide a unique perspective on cyanobacteria and potential cyanotoxin producing taxa that exist in large rivers across the U.S. and can be used to better understand the ambient conditions that may precede bloom events in lotic freshwater ecosystems.
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Affiliation(s)
- David M. Linz
- grid.418698.a0000 0001 2146 2763Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, OH USA
| | - Nathan Sienkiewicz
- grid.418698.a0000 0001 2146 2763Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, OH USA
| | - Ian Struewing
- grid.418698.a0000 0001 2146 2763Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, OH USA
| | - Erin A. Stelzer
- grid.2865.90000000121546924U.S. Geological Survey, Columbus, OH USA
| | | | - Jingrang Lu
- Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, OH, USA.
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Xue Q, Xie L, Cheng C, Su X, Zhao Y. Different environmental factors drive the concentrations of microcystin in particulates, dissolved water, and sediments peaked at different times in a large shallow lake. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 326:116833. [PMID: 36435125 DOI: 10.1016/j.jenvman.2022.116833] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 10/27/2022] [Accepted: 11/17/2022] [Indexed: 06/16/2023]
Abstract
Global distribution and health threats of microcystins (MCs) have received much more attention, but there are still significant knowledge gaps in the peak periods and driving factors of MC in different phases of freshwater ecosystems. Thus, we systematically analyzed the annual variation of different MC congeners (-LR, -RR, and -YR, where L, R, and Y respectively represent leucine, arginine, and tyrosine) in particulates, dissolved water, and sediments in three eutrophic bays of Lake Taihu, China. The results indicated that particulate MCs concentration was the highest, followed by dissolved and sediment MC, with the mean concentration of 7.58 μg/L, 1.48 μg/L, and 0.15 μg/g (DW), respectively. Except for particulate MC, the concentrations of the other two types of MC showed significant differences among the three bays. The dominant congeners of the three types of MCs were different, with the highest proportion of MC-LR being observed in sediment MCs and the lowest in particulate MCs. The peak period of the three types of MC was also different, with particulate MCs reaching their peak in July and October, dissolved MCs in May to July and October, and sediment MCs reaching their peak in September. Consistent with our hypothesis, the dynamics of different types of MCs were driven by different environmental factors. Particulate MCs were primarily related to biological parameters, followed by TP and dissolved carbon. By contrast, dissolved MCs strongly correlated with water temperature and dissolved oxygen. While sediment MCs were primarily driven by properties of sediments, followed by different forms of nitrogen in the water column. Our results suggested that particulate and dissolved MCs in northern Lake Taihu pose high health threats, especially in the peak period. Moreover, a more detailed and targeted risk management strategy should be designed to prevent the possible hazards posed by different types of MC.
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Affiliation(s)
- Qingju Xue
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Liqiang Xie
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Chen Cheng
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaomei Su
- Jiangsu Provincial Key Laboratory of Environmental Engineering, Jiangsu Provincial Academy of Environmental Sciences, Nanjing 210036, China
| | - Yanyan Zhao
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
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18
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Wang S, Zhang X, Chen N, Tian L, Zhang Y, Nam WH. A systematic review and quantitative meta-analysis of the relationships between driving forces and cyanobacterial blooms at global scale. ENVIRONMENTAL RESEARCH 2023; 216:114670. [PMID: 36341794 DOI: 10.1016/j.envres.2022.114670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 10/05/2022] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
The global expansion of cyanobacterial blooms poses a major risk to the safety of freshwater resources. As a result, many explorations have been performed at a regional scale to determine the underlying impact mechanism of cyanobacterial blooms for one or several waterbodies. However, two questions still need to be answered quantitatively at a global scale to assist the water management. One is to specify which factors were often selected as the driving forces of cyanobacterial blooms, and the other is to estimate their quantitative relationships. For that, this paper applied a systematic literature review for 41 peer-reviewed studies published before May 2021 and a statistical meta-analysis based on the Pearson's or Spearman's correlation coefficients from 27 studies. These results showed that the water quality, hydraulic conditions, meteorological conditions and nutrient levels were often considered the driving forces of cyanobacterial blooms in global freshwater systems. Among these, meteorological conditions and nutrient level had the highest probability of being chosen as the driving force. In addition, knowledge of the quantitative relationships between these driving forces and cyanobacterial blooms was newly synthesized based on the correlation coefficients. The results indicated that, at a global scale, meteorological conditions were negatively related to cyanobacterial blooms, and other driving forces, such as water quality, hydraulic conditions and nutrient levels, were positively related to cyanobacterial blooms. In addition, the measurement indicators of these driving forces had diverse forms. For example, the nutrient level can be measured by the concentration of different forms of nitrogen or phosphorus, which may lead to different results in correlation analysis. Thus, a subgroup meta-analysis was necessary for the subdivided driving forces and cyanobacterial blooms, which had a better accuracy. Overall, the synthesized knowledge can help guide advanced cyanobacteria-centered water management, especially when the necessary cyanobacterial data of targeting waterbodies are inaccessible.
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Affiliation(s)
- Siqi Wang
- State Key Laboratory of Information Engineering in Surveying, Mapping, and Remote Sensing (LIESMARS), Wuhan University, Wuhan, 430079, China; Hubei Luojia Laboratory, Wuhan, 430079, China.
| | - Xiang Zhang
- National Engineering Research Center for Geographic Information System, School of Geography and Information Engineering, China University of Geosciences (Wuhan), Wuhan, 430074, China; Hubei Luojia Laboratory, Wuhan, 430079, China.
| | - Nengcheng Chen
- State Key Laboratory of Information Engineering in Surveying, Mapping, and Remote Sensing (LIESMARS), Wuhan University, Wuhan, 430079, China; National Engineering Research Center for Geographic Information System, School of Geography and Information Engineering, China University of Geosciences (Wuhan), Wuhan, 430074, China; Hubei Luojia Laboratory, Wuhan, 430079, China
| | - Liqiao Tian
- State Key Laboratory of Information Engineering in Surveying, Mapping, and Remote Sensing (LIESMARS), Wuhan University, Wuhan, 430079, China
| | - Yan Zhang
- State Key Laboratory of Information Engineering in Surveying, Mapping, and Remote Sensing (LIESMARS), Wuhan University, Wuhan, 430079, China
| | - Won-Ho Nam
- School of Social Safety and Systems Engineering, Institute of Agricultural Environmental Science, National Agricultural Water Research Center, Hankyong National University, Anseong, Republic of Korea
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Wang S, Zhang X, Wang C, Chen N. Multivariable integrated risk assessment for cyanobacterial blooms in eutrophic lakes and its spatiotemporal characteristics. WATER RESEARCH 2023; 228:119367. [PMID: 36417795 DOI: 10.1016/j.watres.2022.119367] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 11/06/2022] [Accepted: 11/15/2022] [Indexed: 06/16/2023]
Abstract
Climate change has catalyzed the global expansion of cyanobacterial blooms in eutrophic , lakes and threatens water security. In most studies, the cyanobacterial bloom risk levels in lakes were evaluated using field-collected data from multiple indicators or spatially continuous data from one cyanobacteria-related indicator. Nevertheless, the occurrence of cyanobacterial blooms in lakes has clear spatial heterogeneity and is affected by numerous factors. Therefore, we developed a multivariable integrated risk assessment framework for cyanobacterial blooms in lakes using five spatially continuous datasets to estimate the risk level of cyanobacterial blooms at the pixel scale (250 m). The spatial and temporal variations in cyanobacterial bloom risk levels from May 1, 2002, to October 31, 2020, were investigated for three typical eutrophic lakes in China: Lakes Taihu, Chaohu, and Dianchi. Seasons and regions of high cyanobacterial bloom risk were identified for each lake. Environmental characteristics were discussed. A long-term investigation revealed that owing to its warm climate, the cyanobacterial risk levels in summer and autumn were much higher than those in the other two seasons. At the synoptic scale, Lake Taihu had a lower cyanobacterial bloom risk than Lakes Chaohu and Dianchi. A further comparison found that precipitation, wind speed, and temperature were responsible for the differences in cyanobacterial bloom risk levels among the three lakes. At the pixel scale, the risk map indicated that the cyanobacterial bloom risk levels of Lake Taihu were unevenly distributed, and the cyanobacterial bloom risk of the lakeshore was higher than that of the other subregions. Nutrient levels played the most critical role in the regional differences in cyanobacterial bloom risk levels in a lake. While the differences of cyanobacterial bloom risk levels in three lakes were resulted by the climates. Bloom events were defined and classified as "long-term bloom" or "flash bloom" according to their duration (over or below a year). Overall, this study can assist in advanced water management with a pixel-scale evaluation of cyanobacterial bloom risk levels.
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Affiliation(s)
- Siqi Wang
- State Key Laboratory of Information Engineering in Surveying, Mapping, and Remote Sensing, Wuhan University, Wuhan 430079, China; Hubei Luojia Laboratory, Wuhan University, Wuhan 430079, China.
| | - Xiang Zhang
- National Engineering Research Centre of Geographic Information System, China University of Geosciences, Wuhan 430074, China; Hubei Luojia Laboratory, Wuhan University, Wuhan 430079, China
| | - Chao Wang
- State Key Laboratory of Information Engineering in Surveying, Mapping, and Remote Sensing, Wuhan University, Wuhan 430079, China; Hubei Luojia Laboratory, Wuhan University, Wuhan 430079, China
| | - Nengcheng Chen
- State Key Laboratory of Information Engineering in Surveying, Mapping, and Remote Sensing, Wuhan University, Wuhan 430079, China; National Engineering Research Centre of Geographic Information System, China University of Geosciences, Wuhan 430074, China; Hubei Luojia Laboratory, Wuhan University, Wuhan 430079, China.
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20
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Butcher JB, Fernandez M, Johnson TE, Shabani A, Lee SS. Geographic Analysis of the Vulnerability of U.S. Lakes to Cyanobacterial Blooms under Future Climate. EARTH INTERACTIONS 2023; 27:1-17. [PMID: 39233817 PMCID: PMC11372659 DOI: 10.1175/ei-d-23-0004.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/06/2024]
Abstract
Cyanobacteria blooms are an increasing concern in U.S. freshwaters. Such blooms can produce nuisance conditions, deplete oxygen, and alter the food chain, and in some cases they may produce potent toxins, although many factors may modulate the relationships between biomass and toxin production. Cyanobacterial blooms are in turn associated with nutrient enrichment and warm water temperatures. Climate change is expected to increase water temperatures and, in many areas, surface runoff that can transport nutrient loads to lakes. While some progress has been made in short-term prediction of cyanobacterial bloom and toxin risk, the long-term projections of which lakes will become more vulnerable to such events as a result of climate change is less clear because of the complex interaction of multiple factors that affect bloom probability. We address this question by reviewing the literature to identify risk factors that increase lake vulnerability to cyanobacterial blooms and evaluating how climate change may alter these factors across the sample of conterminous U.S. lakes contained in the 2007 National Lakes Assessment. Results provide a national-scale assessment of where and in which types of lakes climate change will likely increase the overall risk of cyanobacterial blooms, rather than finer-scale prediction of expected cyanobacterial and toxin levels in individual lakes. This information can be used to guide climate change adaptation planning, including monitoring and management efforts to minimize the effects of increased cyanobacterial prevalence.
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Affiliation(s)
| | - Mark Fernandez
- Tetra Tech, Inc., Research Triangle Park, North Carolina
| | - Thomas E Johnson
- Office of Research and Development, U.S. Environmental Protection Agency, Washington, D.C
| | - Afshin Shabani
- Tetra Tech, Inc., Research Triangle Park, North Carolina
| | - Sylvia S Lee
- Office of Research and Development, U.S. Environmental Protection Agency, Washington, D.C
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21
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Li H, Miller T, Lu J, Goel R. Nitrogen fixation contribution to nitrogen cycling during cyanobacterial blooms in Utah Lake. CHEMOSPHERE 2022; 302:134784. [PMID: 35504465 PMCID: PMC10149033 DOI: 10.1016/j.chemosphere.2022.134784] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 04/23/2022] [Accepted: 04/27/2022] [Indexed: 05/03/2023]
Abstract
Nitrogen (N) cycling is an essential process in lake systems and N-fixation is an important component of it. Recent studies have also found that nitrate reduction through heterotrophic denitrification in lake systems did not prevent harmful cyanobacterial blooms, but instead, may have favored the dominance of N2-fixing cyanobacteria. The overall objective of this study was to estimate nitrogen fixation rates and the expressions of associated nitrogenase (nif gene) functional gene at several sites at different occasions in freshwater Utah Lake. For comparison purposes, one time sampling was also conducted in the brackish Farmington Bay of Great Salt Lake (GSL). The microbial ecology of the top 20-cm of surface water was investigated to assess the dominant cyanobacterial communities and N-related metabolisms. Our study revealed that Dolichospermum and Nodularia were potential N2-fixers for Utah Lake and brackish Farmington Bay, respectively. The in situ N2-fixation rates were 0-0.73 nmol N hr-1L-1 for Utah Lake and 0-0.85 nmol N hr-1L-1 for Farmington Bay, and these rates positively correlated with the abundance and expressions of the nif gene. In addition, nitrate reduction was measured in sediment (0.002-0.094 mg N VSS-1 hr-1). Significantly positive correlations were found among amoA, nirS and nirK abundance (R = 0.56-0.87, p < 0.05, Spearman) in both lakes. An exception was the lower nirK gene abundance detected at one site in Farmington Bay where high ammonium retentions were also detected. Based on a mass balance approach, we concluded that the amount of inorganic N loss through denitrification still exceeded the N input by N2-fixation, much like in most lakes, rivers, and marine ecosystems. This indicates that N cycling processes such as denitrification mediated by heterotrophic bacteria contributes to N-export from the lakes resulting in N limitations.
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Affiliation(s)
- Hanyan Li
- Department of Civil and Environmental Engineering, The University of Utah, 110 S Central Campus Drive, Salt Lake City, UT, 84112, USA
| | - Theron Miller
- Wasatch Front Water Quality Council, Salt Lake City, UT, USA
| | - Jingrang Lu
- United States Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA.
| | - Ramesh Goel
- Department of Civil and Environmental Engineering, The University of Utah, 110 S Central Campus Drive, Salt Lake City, UT, 84112, USA.
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22
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Wang J, Wei ZP, Chu YX, Tian G, He R. Eutrophic levels and algae growth increase emissions of methane and volatile sulfur compounds from lakes. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 306:119435. [PMID: 35550131 DOI: 10.1016/j.envpol.2022.119435] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 05/02/2022] [Accepted: 05/05/2022] [Indexed: 06/15/2023]
Abstract
Eutrophic lakes are hot spots of CH4 and volatile sulfur compound (VSC) emissions, especially during algal blooms and decay. However, the response of CH4 and VSC emissions to lake eutrophication and algae growth as well as the underlying mechanisms remain unclear. In this study, the emissions of CH4 and VSCs from four regions of Lake Taihu with different eutrophic levels were investigated in four months (i.e., March, May, August and December). The CH4 emissions ranged from 20.4 to 126.9 mg m-2 d-1 in the investigated sites and increased with eutrophic levels and temperature. H2S and CS2 were the dominant volatile sulfur compounds (VSCs) emitted from the lake. The CH4 oxidation potential of water ranged from 2.1 to 14.9 μg h-1 L-1, which had positive correlations with trophic level index and the environmental variables except for the NH4+-N concentration. Eutrophic levels could increase the abundances of bacteria and methanotrophs in lake water. α-Proteobacteria methanotroph Methylocystis was more abundant than γ-Proteobacteria methanotrophs in March and May, while the latter was more abundant in August and November. The relative abundance of Cyanobacteria, including Microcystis, A. granulata var. angustissima and Cyanobium had significantly positive correlations with temperature, turbidity, SO42--S, and total sulfur. Partial least squares path modelling revealed that the algal growth could promote VSC emissions, which had a positive correlation with CH4 oxidation potential, likely due to the positive correlation between the CH4 and VSC emissions from lakes. These findings indicate that water eutrophication and algae growth could increase the emissions of CH4 and VSCs from lakes. Controlling algae growth might be an effective way to mitigate the emissions of CH4 and VSCs from freshwater lakes.
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Affiliation(s)
- Jing Wang
- Department of Environmental Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Zhi-Peng Wei
- Hohai University, State Key Laboratory Hydrology-Water Resources and Hydraulic Engineering, Nanjing, 210098, China
| | - Yi-Xuan Chu
- Department of Environmental Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Guangming Tian
- Department of Environmental Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Ruo He
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China; College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China.
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23
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Facey JA, Michie LE, King JJ, Hitchcock JN, Apte SC, Mitrovic SM. Severe cyanobacterial blooms in an Australian lake; causes and factors controlling succession patterns. HARMFUL ALGAE 2022; 117:102284. [PMID: 35944962 DOI: 10.1016/j.hal.2022.102284] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 05/24/2022] [Accepted: 06/28/2022] [Indexed: 06/15/2023]
Abstract
Cyanobacterial blooms have major impacts on the ecological integrity and anthropogenic value of freshwater systems. Chrysosporum ovalisporum, a potentially toxic cyanobacteria has been rare in Australian waters until recently when is has bloomed in a number of lake and river systems. The aim of this study was to determine drivers of its growth and growing dominance. We performed regular monitoring of Mannus Lake, a small freshwater reservoir in South-Eastern Australia that has recently undergone extremely dense bloom events. Blooms of the diazotrophic Chrysosporum ovalisporum occurred in both summers of the 19 month study during periods of persistent thermal stratification. Following the C. ovalisporum blooms, non-diazotrophic taxa (Microcystis aeruginosa and Woronichinia sp.) dominated the phytoplankton community under less stratified conditions. Thermal stratification and nitrogen availability appeared to be the primary drivers of changes in cyanobacterial community structure. We propose that the observed transition from C. ovalisporum to M. aeruginosa and/or Woronichinia sp. may be a result of nitrogen limitation in early summer, which combined with persistent thermal stratification led to an ecological advantage for the nitrogen-fixing C. ovalisporum. Mixing events caused the senescence of the C. ovalisporum bloom, likely supplementing the nutrient budget of the lake with atmospherically derived N and alleviating N limitation to non-diazotrophic taxa. Non-diazotrophic cyanobacterial growth then increased, albeit at much lower biovolumes compared to the initial bloom. Overall, the results demonstrate the role of thermal stratification and nutrient cycling in structuring the cyanobacterial community and provide insights into the environmental factors driving the proliferation of the relatively new, potentially toxic cyanobacterium C. ovalisporum in Australian waters.
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Affiliation(s)
- Jordan A Facey
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW, 2000, Australia.
| | - Laura E Michie
- NSW Department of Primary Industries, Narrandera Fisheries Centre, PO Box 182, Narrandera, New South Wales, 2700, Australia
| | - Josh J King
- CSIRO Land and Water, Lucas Heights, 2234, Australia
| | - James N Hitchcock
- Centre for Applied Water Science, Institute for Applied Ecology, University of Canberra, Australia
| | - Simon C Apte
- CSIRO Land and Water, Lucas Heights, 2234, Australia
| | - Simon M Mitrovic
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW, 2000, Australia
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24
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Duan X, Zhang C, Struewing I, Li X, Allen J, Lu J. Cyanotoxin-encoding genes as powerful predictors of cyanotoxin production during harmful cyanobacterial blooms in an inland freshwater lake: Evaluating a novel early-warning system. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 830:154568. [PMID: 35302035 PMCID: PMC9698223 DOI: 10.1016/j.scitotenv.2022.154568] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 02/26/2022] [Accepted: 03/10/2022] [Indexed: 05/06/2023]
Abstract
Freshwater harmful cyanobacterial blooms (HCBs) potentially produce excessive cyanotoxins, mainly microcystins (MCs), significantly threatening aquatic ecosystems and public health. Accurately predicting HCBs is thus essential to developing effective HCB mitigation and prevention strategies. We previously developed a novel early-warning system that uses cyanotoxin-encoding genes to predict cyanotoxin production in Harsha Lake, Ohio, USA, in 2015. In this study, we evaluated the efficacy of the early-warning system in forecasting the 2016 HCB in the same lake. We also examined potential HCB drivers and cyanobacterial community composition. Our results revealed that the cyanobacterial community was stable at the phylum level but changed dynamically at the genus level over time. Microcystis and Planktothrix were the major MC-producing genera that thrived in June and July and produced high concentrations of MCs (peak level 10.22 μg·L-1). The abundances of the MC-encoding gene cluster mcy and its transcript levels significantly correlated with total MC concentrations (before the MC concentrations peaked) and accurately predicted MC production as revealed by logistic equations. When the Microcystis-specific gene mcyG reached approximately 1.5 × 103 copies·mL-1 or when its transcript level reached approximately 2.4 copies·mL-1, total MC level exceeded 0.3 μg L-1 (a health advisory limit) approximately one week later (weekly sampling scheme). This study suggested that cyanotoxin-encoding genes are promising predictors of MC production in inland freshwater lakes, such as Harsha Lake. The evaluated early-warning system can be a useful tool to assist lake managers in predicting, mitigating, and/or preventing HCBs.
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Affiliation(s)
- Xiaodi Duan
- Pegasus Technical Services, Inc., Cincinnati, OH 45219, USA
| | - Chiqian Zhang
- Pegasus Technical Services, Inc., Cincinnati, OH 45219, USA
| | - Ian Struewing
- Office of Research and Development, United States Environmental Protection Agency, Cincinnati, OH 45268, USA
| | - Xiang Li
- Oak Ridge Institute for Science and Education at the United States Environmental Protection Agency, Cincinnati, OH 45268, USA
| | - Joel Allen
- Office of Research and Development, United States Environmental Protection Agency, Cincinnati, OH 45268, USA
| | - Jingrang Lu
- Office of Research and Development, United States Environmental Protection Agency, Cincinnati, OH 45268, USA.
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25
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Biodegradation of Nodularin by a Microcystin-Degrading Bacterium: Performance, Degradation Pathway, and Potential Application. Toxins (Basel) 2021; 13:toxins13110813. [PMID: 34822597 PMCID: PMC8618024 DOI: 10.3390/toxins13110813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/15/2021] [Accepted: 11/15/2021] [Indexed: 01/19/2023] Open
Abstract
Currently, studies worldwide have comprehensively recognized the importance of Sphingomonadaceae bacteria and the mlrCABD gene cluster in microcystin (MC) degradation. However, knowledge about their degradation of nodularin (NOD) is still unclear. In this study, the degradation mechanism of NOD by Sphingopyxis sp. m6, an efficient MC degrader isolated from Lake Taihu, was investigated in several aspects, including degradation ability, degradation products, and potential application. The strain degraded NOD of 0.50 mg/L with a zero-order rate constant of 0.1656 mg/L/d and a half-life of 36 h. The average degradation rate of NOD was significantly influenced by the temperature, pH, and initial toxin concentrations. Moreover, four different biodegradation products, linear NOD, tetrapeptide H-Glu-Mdhb-MeAsp-Arg-OH, tripeptide H-Mdhb-MeAsp-Arg-OH, and dipeptide H-MeAsp-Arg-OH, were identified, of which the latter two are the first reported. Furthermore, the four mlr genes were upregulated during NOD degradation. The microcystinase MlrA encoded by the mlrA gene hydrolyzes the Arg-Adda bond to generate linear NOD as the first step of NOD biodegradation. Notably, recombinant MlrA showed higher degradation activity and stronger environmental adaptability than the wild strain, suggesting future applications in NOD pollution remediation. This research proposes a relatively complete NOD microbial degradation pathway, which lays a foundation for exploring the mechanisms of NOD degradation by MC-degrading bacteria.
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