Research

14 pages, 2128 KiB

Open AccessArticle

Can Alkyl Quaternary Ammonium Cations Substitute H₂O₂ in Controlling Cyanobacterial Blooms—Laboratory and Mesocosm Studies

by Xinya Zhang, Yiruo Xia, Yunlu Jia, Assaf Sukenik, Aaron Kaplan, Chanyuan Song, Guofei Dai, Fang Bai, Lin Li and Lirong Song

Microorganisms 2021, 9(11), 2258; https://doi.org/10.3390/microorganisms9112258 - 29 Oct 2021

Cited by 4 | Viewed by 1521

Abstract

Mitigation of harmful cyanobacterial blooms that constitute a serious threat to water quality, particularly in eutrophic water, such as in aquaculture, is essential. Thus, in this study, we tested the efficacy of selected cyanocides towards bloom control in laboratory and outdoor mesocosm experiments. [...] Read more.

Mitigation of harmful cyanobacterial blooms that constitute a serious threat to water quality, particularly in eutrophic water, such as in aquaculture, is essential. Thus, in this study, we tested the efficacy of selected cyanocides towards bloom control in laboratory and outdoor mesocosm experiments. Specifically, we focused on the applicability of a group of cationic disinfectants, alkyltrimethyl ammonium (ATMA) compounds and H₂O₂. The biocidal effect of four ATMA cations with different alkyl chain lengths was evaluated ex situ using Microcystis colonies collected from a fish pond. The most effective compound, octadecyl trimethyl ammonium (ODTMA), was further evaluated for its selectivity towards 24 cyanobacteria and eukaryotic algae species, including Cyanobacteria, Chlorophyta, Bacillariophyta, Euglenozoa and Cryptophyta. The results indicated selective inhibition of cyanobacteria by ODTMA-Br (C18) on both Chroccocales and Nostocales, but a minor effect on Chlorophytes and Bacillariophytes. The efficacy of ODTMA-Br (C18) (6.4 μM) in mitigating the Microcystis population was compared with that of a single low dose of H₂O₂ treatments (117.6 μM). ODTMA-Br (C18) suppressed the regrowth of Microcystis for a longer duration than did H₂O₂. The results suggested that ODTMA-Br (C18) may be used as an effective cyanocide and that it is worth further evaluating this group of cationic compounds as a treatment to mitigate cyanobacterial blooms in aquaculture. Full article

(This article belongs to the Special Issue Global Intensification of Cyanobacterial Blooms: The Driving Forces and Mitigation Approaches)

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25 pages, 8691 KiB

Open AccessArticle

Bioavailable Nutrients (N and P) and Precipitation Patterns Drive Cyanobacterial Blooms in Missisquoi Bay, Lake Champlain

by Sukriye Celikkol, Nathalie Fortin, Nicolas Tromas, Herinandrianina Andriananjamanantsoa and Charles W. Greer

Microorganisms 2021, 9(10), 2097; https://doi.org/10.3390/microorganisms9102097 - 04 Oct 2021

Cited by 13 | Viewed by 2385

Abstract

Anthropogenic activities release large amounts of nitrogen (N) and phosphorus (P) nutrients into the environment. Sources of nutrients include surface and sub-surface runoffs from agricultural practices with the application of chemical fertilizers and manure as well as combined sewer overflows (CSOs). Nutrient runoffs [...] Read more.

Anthropogenic activities release large amounts of nitrogen (N) and phosphorus (P) nutrients into the environment. Sources of nutrients include surface and sub-surface runoffs from agricultural practices with the application of chemical fertilizers and manure as well as combined sewer overflows (CSOs). Nutrient runoffs contribute to the eutrophication of aquatic ecosystems and enhance the growth of cyanobacteria. Precipitation is an important driving force behind the runoff of nutrients from agricultural fields into surrounding water bodies. To understand the dynamics between nutrient input, precipitation and cyanobacterial growth in Missisquoi Bay, Lake Champlain (Quebec), one location in Pike River (a major tributary into the bay) and four locations in Missisquoi Bay were monitored from April to November in 2017 and 2018. Biweekly water samples were analyzed using chemical methods and high-throughput sequencing of 16S rRNA gene amplicons. High concentrations of N and P were typically measured in April and May. Three major spikes in nutrient concentrations were observed in early and mid-summer as well as early fall, all of which were associated with intense cumulative precipitation events of 40 to 100 mm within 7 days prior to sampling. Despite the high concentrations of nutrients in the spring and early summer, the cyanobacterial blooms appeared in mid to late summer as the water temperature increased. Dolichospermum sp. was the major bloom-forming cyanobacterium during both summers. A second intense bloom event of Microcystis was also observed in the fall (October and November) for both years. Variation in the cyanobacteria population was strongly associated with inorganic and readily available fractions of N and P such as nitrites and nitrates (NOx), ammonia (NH₃) and dissolved organic phosphorus (DOP). During blooms, total Kjeldahl nitrogen (TKN) and total particulate phosphorus (TPP) fractions had a substantial influence on total nitrogen (TN) and total phosphorus (TP) concentrations, respectively. The abundance of bacteria involved in the metabolism of nitrogen compared to that of phosphorus revealed the importance of nitrogen on overall microbial dynamics as well as CB formation in the bay. Our findings emphasize the combined influence of precipitation events, temperature and several bioavailable fractions of nitrogen and phosphorus on cyanobacterial bloom episodes. Full article

(This article belongs to the Special Issue Global Intensification of Cyanobacterial Blooms: The Driving Forces and Mitigation Approaches)

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20 pages, 2863 KiB

Open AccessArticle

Remediation Strategies to Control Toxic Cyanobacterial Blooms: Effects of Macrophyte Aqueous Extracts on Microcystis aeruginosa (Growth, Toxin Production and Oxidative Stress Response) and on Bacterial Ectoenzymatic Activities

by Zakaria Tazart, Maura Manganelli, Simona Scardala, Franca Maria Buratti, Federica Nigro Di Gregorio, Mountasser Douma, Khadija Mouhri, Emanuela Testai and Mohammed Loudiki

Microorganisms 2021, 9(8), 1782; https://doi.org/10.3390/microorganisms9081782 - 23 Aug 2021

Cited by 7 | Viewed by 2583

Abstract

Increasing toxic cyanobacterial blooms in freshwater demand environmentally friendly solutions to control their growth and toxicity, especially in arid countries, where most drinking water is produced from surface reservoirs. We tested the effects of macrophyte allelochemicals on Microcystis aeruginosa and on the fundamental [...] Read more.

Increasing toxic cyanobacterial blooms in freshwater demand environmentally friendly solutions to control their growth and toxicity, especially in arid countries, where most drinking water is produced from surface reservoirs. We tested the effects of macrophyte allelochemicals on Microcystis aeruginosa and on the fundamental role of bacteria in nutrient recycling. The effects of Ranunculus aquatilis aqueous extract, the most bioactive of four Moroccan macrophyte extracts, were tested in batch systems on M. aeruginosa growth, toxin production and oxidative stress response and on the ectoenzymatic activity associated with the bacterial community. M. aeruginosa density was reduced by 82.18%, and a significant increase in oxidative stress markers was evidenced in cyanobacterial cells. Microcystin concentration significantly decreased, and they were detected only intracellularly, an important aspect in managing toxic blooms. R. aquatilis extract had no negative effects on associated bacteria. These results confirm a promising use of macrophyte extracts, but they cannot be generalized. The use of the extract on other toxic strains, such as Planktothrix rubescens, Raphidiopsis raciborskii and Chrysosporum ovalisporum, caused a reduction in growth rate but not in cyanotoxin content, increasing toxicity. The need to assess species-specific cyanobacteria responses to verify the efficacy and safety of the extracts for human health and the environment is highlighted. Full article

(This article belongs to the Special Issue Global Intensification of Cyanobacterial Blooms: The Driving Forces and Mitigation Approaches)

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17 pages, 6439 KiB

Open AccessArticle

Depth-Dependent Spatiotemporal Dynamics of Overwintering Pelagic Microcystis in a Temperate Water Body

by Haolun Tian, Junjie Jin, Bojian Chen, Daniel D. Lefebvre, Stephen C. Lougheed and Yuxiang Wang

Microorganisms 2021, 9(8), 1718; https://doi.org/10.3390/microorganisms9081718 - 12 Aug 2021

Viewed by 2377

Abstract

Cyanobacteria in the genus Microcystis are dominant components of many harmful algal blooms worldwide. Their pelagic–benthic life cycle helps them survive periods of adverse conditions and contributes greatly to their ecological success. Many studies on Microcystis overwintering have focused on benthic colonies and [...] Read more.

Cyanobacteria in the genus Microcystis are dominant components of many harmful algal blooms worldwide. Their pelagic–benthic life cycle helps them survive periods of adverse conditions and contributes greatly to their ecological success. Many studies on Microcystis overwintering have focused on benthic colonies and suggest that sediment serves as the major inoculum for subsequent summer blooms. However, the contemporaneous overwintering pelagic population may be important as well but is understudied. In this study, we investigated near-surface and near-bottom pelagic population dynamics of both microcystin-producing Microcystis and total Microcystis over six weeks in winter at Dog Lake (South Frontenac, ON, Canada). We quantified relative Microcystis concentrations using real-time PCR. Our results showed that the spatiotemporal distribution of overwintering pelagic Microcystis was depth dependent. The abundance of near-bottom pelagic Microcystis declined with increased depth with no influence of depth on near-surface Microcystis abundance. In the shallow region of the lake (<10 m), most pelagic Microcystis was found near the lake bottom (>90%). However, the proportion of near-surface Microcystis rose sharply to over 60% as the depth increased to approximately 18 m. The depth-dependent distribution pattern was found to be similar in both microcystin-producing Microcystis and total Microcystis. Our results suggest the top of the water column may be a more significant contributor of Microcystis recruitment inoculum than previously thought and merits more attention in early CHAB characterization and remediation. Full article

(This article belongs to the Special Issue Global Intensification of Cyanobacterial Blooms: The Driving Forces and Mitigation Approaches)

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17 pages, 3029 KiB

Open AccessArticle

Simultaneous Removal of the Freshwater Bloom-Forming Cyanobacterium Microcystis and Cyanotoxin Microcystins via Combined Use of Algicidal Bacterial Filtrate and the Microcystin-Degrading Enzymatic Agent, MlrA

by Suqin Wang, Siyu Yang, Jun Zuo, Chenlin Hu, Lirong Song, Nanqin Gan and Peng Chen

Microorganisms 2021, 9(8), 1594; https://doi.org/10.3390/microorganisms9081594 - 27 Jul 2021

Cited by 8 | Viewed by 2494

Abstract

Freshwater cyanobacterial blooms (e.g., Microcystis blooms) constitute a major global environmental problem because of their risks to public health and aquatic ecological systems. Current physicochemical treatments of toxic cyanobacteria cause the significant release of cyanotoxin microcystins from damaged cells. Biological control is a [...] Read more.

Freshwater cyanobacterial blooms (e.g., Microcystis blooms) constitute a major global environmental problem because of their risks to public health and aquatic ecological systems. Current physicochemical treatments of toxic cyanobacteria cause the significant release of cyanotoxin microcystins from damaged cells. Biological control is a promising eco-friendly technology to manage harmful cyanobacteria and cyanotoxins. Here, we demonstrated an efficient biological control strategy at the laboratory scale to simultaneously remove Microcystis and microcystins via the combined use of the algicidal bacterial filtrate and the microcystin-degrading enzymatic agent. The algicidal indigenous bacterium Paenibacillus sp. SJ-73 was isolated from the sediment of northern Lake Taihu, China, and the microcystin-degrading enzymatic agent (MlrA) was prepared via the heterologous expression of the mlrA gene in the indigenous microcystin-degrading bacterium Sphingopyxis sp. HW isolated from Lake Taihu. The single use of a fermentation filtrate (5%, v/v) of Paenibacillus sp. SJ-73 for seven days removed the unicellular Microcystis aeruginosa PCC 7806 and the native colonial Microcystis strain TH1701 in Lake Taihu by 84% and 92%, respectively, whereas the single use of MlrA removed 85% of microcystins. Used in combination, the fermentation filtrate and MlrA removed Microcystis TH1701 and microcystins by 92% and 79%, respectively. The present biological control thus provides an important technical basis for the further development of safe, efficient, and effective measures to manage Microcystis blooms and microcystins in natural waterbodies. Full article

(This article belongs to the Special Issue Global Intensification of Cyanobacterial Blooms: The Driving Forces and Mitigation Approaches)

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19 pages, 2514 KiB

Open AccessArticle

Differential Labeling of Chemically Modified Peptides and Lipids among Cyanobacteria Planktothrix and Microcystis

by Rubén Morón-Asensio, David Schuler, Anneliese Wiedlroither, Martin Offterdinger and Rainer Kurmayer

Microorganisms 2021, 9(8), 1578; https://doi.org/10.3390/microorganisms9081578 - 24 Jul 2021

Cited by 2 | Viewed by 2667 | Correction

Abstract

The cyanoHAB forming cyanobacteria Microcystis and Planktothrix frequently produce high intracellular amounts of microcystins (MCs) or anabaenopeptins (APs). In this study, chemically modified MCs and APs have been localized on a subcellular level in Microcystis and Planktothrix applying copper-catalyzed alkyne-azide cycloaddition (CuACC). For [...] Read more.

The cyanoHAB forming cyanobacteria Microcystis and Planktothrix frequently produce high intracellular amounts of microcystins (MCs) or anabaenopeptins (APs). In this study, chemically modified MCs and APs have been localized on a subcellular level in Microcystis and Planktothrix applying copper-catalyzed alkyne-azide cycloaddition (CuACC). For this purpose, three different non-natural amino acids carrying alkyne or azide moieties were fed to individual P. agardhii strains No371/1 and CYA126/8 as well as to M. aeruginosa strain Hofbauer showing promiscuous incorporation of various amino acid substrates during non-ribosomal peptide synthesis (NRPS). Moreover, CYA126/8 peptide knock-out mutants and non-toxic strain Synechocystis PCC6803 were processed under identical conditions. Simultaneous labeling of modified peptides with ALEXA405 and ALEXA488 and lipid staining with BODIPY 505/515 were performed to investigate the intracellular location of the modified peptides. Pearson correlation coefficients (PCC) obtained from confocal images were calculated between the different fluorophores and the natural autofluorescence (AF), and between labeled modified peptides and dyed lipids to investigate the spatial overlap between peptides and the photosynthetic complex, and between peptides and lipids. Overall, labeling of modified MCs (M. aeruginosa) and APs (P. agardhii) using both fluorophores revealed increased intensity in MC/AP producing strains. For Synechocystis lacking NRPS, no labeling using either ALEXA405 or ALEXA488 was observed. Lipid staining in M. aeruginosa and Synechocystis was intense while in Planktothrix it was more variable. When compared with AF, both modified peptides and lipids showed a heterologous distribution. In comparison, the correlation between stained lipids and labeled peptides was not increased suggesting a reduced spatial overlap. Full article

(This article belongs to the Special Issue Global Intensification of Cyanobacterial Blooms: The Driving Forces and Mitigation Approaches)

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28 pages, 3734 KiB

Open AccessEditor’s ChoiceArticle

Resilience of Microbial Communities after Hydrogen Peroxide Treatment of a Eutrophic Lake to Suppress Harmful Cyanobacterial Blooms

by Tim Piel, Giovanni Sandrini, Gerard Muyzer, Corina P. D. Brussaard, Pieter C. Slot, Maria J. van Herk, Jef Huisman and Petra M. Visser

Microorganisms 2021, 9(7), 1495; https://doi.org/10.3390/microorganisms9071495 - 13 Jul 2021

Cited by 19 | Viewed by 5141

Abstract

Applying low concentrations of hydrogen peroxide (H₂O₂) to lakes is an emerging method to mitigate harmful cyanobacterial blooms. While cyanobacteria are very sensitive to H₂O₂, little is known about the impacts of these H₂ [...] Read more.

Applying low concentrations of hydrogen peroxide (H₂O₂) to lakes is an emerging method to mitigate harmful cyanobacterial blooms. While cyanobacteria are very sensitive to H₂O₂, little is known about the impacts of these H₂O₂ treatments on other members of the microbial community. In this study, we investigated changes in microbial community composition during two lake treatments with low H₂O₂ concentrations (target: 2.5 mg L⁻¹) and in two series of controlled lake incubations. The results show that the H₂O₂ treatments effectively suppressed the dominant cyanobacteria Aphanizomenon klebahnii, Dolichospermum sp. and, to a lesser extent, Planktothrix agardhii. Microbial community analysis revealed that several Proteobacteria (e.g., Alteromonadales, Pseudomonadales, Rhodobacterales) profited from the treatments, whereas some bacterial taxa declined (e.g., Verrucomicrobia). In particular, the taxa known to be resistant to oxidative stress (e.g., Rheinheimera) strongly increased in relative abundance during the first 24 h after H₂O₂ addition, but subsequently declined again. Alpha and beta diversity showed a temporary decline but recovered within a few days, demonstrating resilience of the microbial community. The predicted functionality of the microbial community revealed a temporary increase of anti-ROS defenses and glycoside hydrolases but otherwise remained stable throughout the treatments. We conclude that the use of low concentrations of H₂O₂ to suppress cyanobacterial blooms provides a short-term pulse disturbance but is not detrimental to lake microbial communities and their ecosystem functioning. Full article

(This article belongs to the Special Issue Global Intensification of Cyanobacterial Blooms: The Driving Forces and Mitigation Approaches)

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14 pages, 29430 KiB

Open AccessArticle

Diel Variations of Extracellular Microcystin Influence the Subcellular Dynamics of RubisCO in Microcystis aeruginosa PCC 7806

by Arthur Guljamow, Tino Barchewitz, Rebecca Große, Stefan Timm, Martin Hagemann and Elke Dittmann

Microorganisms 2021, 9(6), 1265; https://doi.org/10.3390/microorganisms9061265 - 10 Jun 2021

Cited by 7 | Viewed by 2696

Abstract

The ubiquitous freshwater cyanobacterium Microcystis is remarkably successful, showing a high tolerance against fluctuations in environmental conditions. It frequently forms dense blooms which can accumulate significant amounts of the hepatotoxin microcystin, which plays an extracellular role as an infochemical but also acts intracellularly [...] Read more.

The ubiquitous freshwater cyanobacterium Microcystis is remarkably successful, showing a high tolerance against fluctuations in environmental conditions. It frequently forms dense blooms which can accumulate significant amounts of the hepatotoxin microcystin, which plays an extracellular role as an infochemical but also acts intracellularly by interacting with proteins of the carbon metabolism, notably with the CO₂ fixing enzyme RubisCO. Here we demonstrate a direct link between external microcystin and its intracellular targets. Monitoring liquid cultures of Microcystis in a diel experiment revealed fluctuations in the extracellular microcystin content that correlate with an increase in the binding of microcystin to intracellular proteins. Concomitantly, reversible relocation of RubisCO from the cytoplasm to the cell’s periphery was observed. These variations in RubisCO localization were especially pronounced with cultures grown at higher cell densities. We replicated these effects by adding microcystin externally to cultures grown under continuous light. Thus, we propose that microcystin may be part of a fast response to conditions of high light and low carbon that contribute to the metabolic flexibility and the success of Microcystis in the field. Full article

(This article belongs to the Special Issue Global Intensification of Cyanobacterial Blooms: The Driving Forces and Mitigation Approaches)

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19 pages, 4086 KiB

Open AccessArticle

Quantitative Proteomic and Microcystin Production Response of Microcystis aeruginosa to Phosphorus Depletion

by Nian Wei, Lirong Song and Nanqin Gan

Microorganisms 2021, 9(6), 1183; https://doi.org/10.3390/microorganisms9061183 - 31 May 2021

Cited by 16 | Viewed by 2487

Abstract

Microcystis blooms are the most widely distributed and frequently occurring cyanobacterial blooms in freshwater. Reducing phosphorus is suggested to be effective in mitigating cyanobacterial blooms, while the underlying molecular mechanisms are yet to be elucidated. In the present study, isobaric tags for relative [...] Read more.

Microcystis blooms are the most widely distributed and frequently occurring cyanobacterial blooms in freshwater. Reducing phosphorus is suggested to be effective in mitigating cyanobacterial blooms, while the underlying molecular mechanisms are yet to be elucidated. In the present study, isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomics was employed to study the effects of phosphorus depletion on Microcystis aeruginosa FACHB-905. The production of microcystins (MCs), a severe hazard of Microcystis blooms, was also analyzed. In total, 230 proteins were found to be differentially abundant, with 136 downregulated proteins. The results revealed that, upon phosphorus limitation stress, Microcystis aeruginosa FACHB-905 raised the availability of phosphorus primarily by upregulating the expression of orthophosphate transport system proteins, with no alkaline phosphatase producing ability. Phosphorus depletion remarkably inhibited cell growth and the primary metabolic processes of Microcystis, including transcription, translation and photosynthesis, with structures of photosystems remaining intact. Moreover, expression of nitrogen assimilation proteins was downregulated, while proteins involved in carbon catabolism were significantly upregulated, which was considered beneficial for the intracellular balance among carbon, nitrogen and phosphorus. The expression of MC synthetase was not significantly different upon phosphorus depletion, while MC content was significantly suppressed. It is assumed that phosphorus depletion indirectly regulates the production of MC by the inhibition of metabolic processes and energy production. These results contribute to further understanding of the influence mechanisms of phosphorus depletion on both biological processes and MC production in Microcystis cells. Full article

(This article belongs to the Special Issue Global Intensification of Cyanobacterial Blooms: The Driving Forces and Mitigation Approaches)

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24 pages, 2916 KiB

Open AccessArticle

Does the Kis-Balaton Water Protection System (KBWPS) Effectively Safeguard Lake Balaton from Toxic Cyanobacterial Blooms?

by Zoran Marinović, Nada Tokodi, Damjana Drobac Backović, Ilija Šćekić, Nevena Kitanović, Snežana B. Simić, Nevena B. Đorđević, Árpád Ferincz, Ádám Staszny, Tamara Dulić, Jussi Meriluoto, Béla Urbányi, Jelena Lujić and Zorica Svirčev

Microorganisms 2021, 9(5), 960; https://doi.org/10.3390/microorganisms9050960 - 29 Apr 2021

Cited by 4 | Viewed by 2404

Abstract

Lake Balaton is the largest shallow lake in Central Europe. Its water quality is affected by its biggest inflow, the Zala River. During late 20th century, a wetland area named the Kis-Balaton Water Protection System (KBWPS) was constructed in the hopes that it [...] Read more.

Lake Balaton is the largest shallow lake in Central Europe. Its water quality is affected by its biggest inflow, the Zala River. During late 20th century, a wetland area named the Kis-Balaton Water Protection System (KBWPS) was constructed in the hopes that it would act as a filter zone and thus ameliorate the water quality of Lake Balaton. The aim of the present study was to test whether the KBWPS effectively safeguards Lake Balaton against toxic cyanobacterial blooms. During April, May, July and September 2018, severe cyanobacterial blooming was observed in the KBWPS with numbers reaching up to 13 million cells/mL at the peak of the bloom (July 2018). MC- and STX-coding genes were detected in the cyanobacterial biomass. Five out of nine tested microcystin congeners were detected at the peak of the bloom with the concentrations of MC-LR reaching 1.29 µg/L; however, accumulation of MCs was not detected in fish tissues. Histopathological analyses displayed severe hepatopancreas, kidney and gill alterations in fish obtained throughout the investigated period. In Lake Balaton, on the other hand, cyanobacterial numbers were much lower; more than 400-fold fewer cells/mL were detected during June 2018 and cyanotoxins were not detected in the water. Hepatic, kidney and gill tissue displayed few alterations and resembled the structure of control fish. We can conclude that the KBWPS acts as a significant buffering zone, thus protecting the water quality of Lake Balaton. However, as MC- and STX-coding genes in the cyanobacterial biomass were detected at both sites, regular monitoring of this valuable ecosystem for the presence of cyanobacteria and cyanotoxins is of paramount importance. Full article

(This article belongs to the Special Issue Global Intensification of Cyanobacterial Blooms: The Driving Forces and Mitigation Approaches)

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Review

Jump to: Research, Other

25 pages, 1162 KiB

Open AccessReview

Reviewing Interspecies Interactions as a Driving Force Affecting the Community Structure in Lakes via Cyanotoxins

by Azam Omidi, Stephan Pflugmacher, Aaron Kaplan, Young Jun Kim and Maranda Esterhuizen

Microorganisms 2021, 9(8), 1583; https://doi.org/10.3390/microorganisms9081583 - 25 Jul 2021

Cited by 11 | Viewed by 3220

Abstract

The escalating occurrence of toxic cyanobacterial blooms worldwide is a matter of concern. Global warming and eutrophication play a major role in the regularity of cyanobacterial blooms, which has noticeably shifted towards the predomination of toxic populations. Therefore, understanding the effects of cyanobacterial [...] Read more.

The escalating occurrence of toxic cyanobacterial blooms worldwide is a matter of concern. Global warming and eutrophication play a major role in the regularity of cyanobacterial blooms, which has noticeably shifted towards the predomination of toxic populations. Therefore, understanding the effects of cyanobacterial toxins in aquatic ecosystems and their advantages to the producers are of growing interest. In this paper, the current literature is critically reviewed to provide further insights into the ecological contribution of cyanotoxins in the variation of the lake community diversity and structure through interspecies interplay. The most commonly detected and studied cyanobacterial toxins, namely the microcystins, anatoxins, saxitoxins, cylindrospermopsins and β-N-methylamino-L-alanine, and their ecotoxicity on various trophic levels are discussed. This work addresses the environmental characterization of pure toxins, toxin-containing crude extracts and filtrates of single and mixed cultures in interspecies interactions by inducing different physiological and metabolic responses. More data on these interactions under natural conditions and laboratory-based studies using direct co-cultivation approaches will provide more substantial information on the consequences of cyanotoxins in the natural ecosystem. This review is beneficial for understanding cyanotoxin-mediated interspecies interactions, developing bloom mitigation technologies and robustly assessing the hazards posed by toxin-producing cyanobacteria to humans and other organisms. Full article

(This article belongs to the Special Issue Global Intensification of Cyanobacterial Blooms: The Driving Forces and Mitigation Approaches)

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24 pages, 1857 KiB

Open AccessReview

Cyanobacterial Harmful Algal Blooms in Aquatic Ecosystems: A Comprehensive Outlook on Current and Emerging Mitigation and Control Approaches

by Assaf Sukenik and Aaron Kaplan

Microorganisms 2021, 9(7), 1472; https://doi.org/10.3390/microorganisms9071472 - 09 Jul 2021

Cited by 67 | Viewed by 7489

Abstract

An intensification of toxic cyanobacteria blooms has occurred over the last three decades, severely affecting coastal and lake water quality in many parts of the world. Extensive research is being conducted in an attempt to gain a better understanding of the driving forces [...] Read more.

An intensification of toxic cyanobacteria blooms has occurred over the last three decades, severely affecting coastal and lake water quality in many parts of the world. Extensive research is being conducted in an attempt to gain a better understanding of the driving forces that alter the ecological balance in water bodies and of the biological role of the secondary metabolites, toxins included, produced by the cyanobacteria. In the long-term, such knowledge may help to develop the needed procedures to restore the phytoplankton community to the pre-toxic blooms era. In the short-term, the mission of the scientific community is to develop novel approaches to mitigate the blooms and thereby restore the ability of affected communities to enjoy coastal and lake waters. Here, we critically review some of the recently proposed, currently leading, and potentially emerging mitigation approaches in-lake novel methodologies and applications relevant to drinking-water treatment. Full article

(This article belongs to the Special Issue Global Intensification of Cyanobacterial Blooms: The Driving Forces and Mitigation Approaches)

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Other

Jump to: Research, Review

5 pages, 1487 KiB

Open AccessCorrection

Correction: Morón-Asensio et al. Differential Labeling of Chemically Modified Peptides and Lipids among Cyanobacteria Planktothrix and Microcystis. Microorganisms 2021, 9, 1578

by Rubén Morón-Asensio, David Schuler, Anneliese Wiedlroither, Martin Offterdinger and Rainer Kurmayer

Microorganisms 2022, 10(4), 695; https://doi.org/10.3390/microorganisms10040695 - 24 Mar 2022

Viewed by 1195

Abstract

The authors wish to make the following corrections to this paper [...] Full article

(This article belongs to the Special Issue Global Intensification of Cyanobacterial Blooms: The Driving Forces and Mitigation Approaches)

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