1
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Jiang J, Zeng J, Wang J, Zuo J, Wei N, Song L, Shan K, Gan N. Changes in CO 2 concentration drive a succession of toxic and non-toxic strains of Microcystis blooms. WATER RESEARCH 2024; 250:121056. [PMID: 38171175 DOI: 10.1016/j.watres.2023.121056] [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: 09/25/2023] [Revised: 11/30/2023] [Accepted: 12/21/2023] [Indexed: 01/05/2024]
Abstract
The dynamic changes between toxic and non-toxic strains of Microcystis blooms have always been a hot topic. Previous studies have found that low CO2 favors toxic strains, but how changing dissolved CO2 (CO2 [aq]) in water body influences the succession of toxic and non-toxic strains in Microcystis blooms remains uncertain. Here, we combined laboratory competition experiments, field observations, and a machine learning model to reveal the links between CO2 changes and the succession. Laboratory experiments showed that under low CO2 conditions (100-150 ppm), the toxic strains could make better use of CO2 (aq) and be dominant. The non-toxic strains demonstrated a growth advantage as CO2 concentration increased (400-1000 ppm). Field observations from June to November in Lake Taihu showed that the percentage of toxic strains increased as CO2 (aq) decreased. Machine learning highlighted links between the inorganic carbon concentration and the proportion of advantageous strains. Our findings provide new insights for cyanoHABs prediction and prevention.
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Affiliation(s)
- Jingyu Jiang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China,; University of Chinese Academy of Sciences, Beijing, China
| | - Jiaying Zeng
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China,; University of Chinese Academy of Sciences, Beijing, China
| | - Jingkai Wang
- University of Chinese Academy of Sciences, Beijing, China,; Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China
| | - Jun Zuo
- National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Zhejiang Provincial Key Lab for Water Environment and Marine Biological Resources Protection, Institute for Eco-Environmental Research of Sanyang Wetland, Wenzhou University, Wenzhou 325035, China
| | - Nian Wei
- Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China
| | - Lirong Song
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China,; University of Chinese Academy of Sciences, Beijing, China
| | - Kun Shan
- University of Chinese Academy of Sciences, Beijing, China,; Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China,.
| | - Nanqin Gan
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China,; University of Chinese Academy of Sciences, Beijing, China,.
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2
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Stark GF, Martin RM, Smith LE, Wei B, Hellweger FL, Bullerjahn GS, McKay RML, Boyer GL, Wilhelm SW. Microcystin aids in cold temperature acclimation: Differences between a toxic Microcystis wildtype and non-toxic mutant. HARMFUL ALGAE 2023; 129:102531. [PMID: 37951605 PMCID: PMC10640677 DOI: 10.1016/j.hal.2023.102531] [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: 08/31/2023] [Revised: 10/20/2023] [Accepted: 10/20/2023] [Indexed: 11/14/2023]
Abstract
For Microcystis aeruginosa PCC 7806, temperature decreases from 26 °C to 19 °C double the microcystin quota per cell during growth in continuous culture. Here we tested whether this increase in microcystin provided M. aeruginosa PCC 7806 with a fitness advantage during colder-temperature growth by comparing cell concentration, cellular physiology, reactive oxygen species damage, and the transcriptomics-inferred metabolism to a non-toxigenic mutant strain M. aeruginosa PCC 7806 ΔmcyB. Photo-physiological data combined with transcriptomic data revealed metabolic changes in the mutant strain during growth at 19 °C, which included increased electron sinks and non-photochemical quenching. Increased gene expression was observed for a glutathione-dependent peroxiredoxin during cold treatment, suggesting compensatory mechanisms to defend against reactive oxygen species are employed in the absence of microcystin in the mutant. Our observations highlight the potential selective advantages of a longer-term defensive strategy in management of oxidative stress (i.e., making microcystin) vs the shorter-term proactive strategy of producing cellular components to actively dissipate or degrade oxidative stress agents.
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Affiliation(s)
- Gwendolyn F Stark
- Department of Microbiology, The University of Tennessee, Knoxville, TN, USA
| | - Robbie M Martin
- Department of Microbiology, The University of Tennessee, Knoxville, TN, USA
| | - Laura E Smith
- Department of Microbiology, The University of Tennessee, Knoxville, TN, USA
| | - Bofan Wei
- Department of Chemistry, State University of New York College of Environmental Science and Forestry, Syracuse, NY, USA
| | - Ferdi L Hellweger
- Water Quality Engineering, Technical University of Berlin, Berlin, Germany
| | - George S Bullerjahn
- Department of Biological Sciences, Bowling Green State University, Bowling Green, OH, USA
| | - R Michael L McKay
- Great Lakes Institute for Environmental Research, The University of Windsor, Windsor, ON, Canada
| | - Gregory L Boyer
- Department of Chemistry, State University of New York College of Environmental Science and Forestry, Syracuse, NY, USA
| | - Steven W Wilhelm
- Department of Microbiology, The University of Tennessee, Knoxville, TN, USA.
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3
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Stark GF, Martin RM, Smith LE, Wei B, Hellweger FL, Bullerjahn GS, McKay RML, Boyer GL, Wilhelm SW. Cool temperature acclimation in toxigenic Microcystis aeruginosa PCC 7806 and its non-toxigenic mutant. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.28.555099. [PMID: 37693631 PMCID: PMC10491114 DOI: 10.1101/2023.08.28.555099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
For Microcystis aeruginosa PCC 7806, temperature decreases from 26° C to 19° C double the microcystin quota per cell during growth in continuous culture. Here we tested whether this increase in microcystin provided M. aeruginosa PCC 7806 with a fitness advantage during colder-temperature growth by comparing cell concentration, cellular physiology, and the transcriptomics-inferred metabolism to a non-toxigenic mutant strain M. aeruginosa PCC 7806 ΔmcyB. Photo-physiological data combined with transcriptomic data revealed metabolic changes in the mutant strain during growth at 19° C, which included increased electron sinks and non-photochemical quenching. Increased gene expression was observed for a glutathione-dependent peroxiredoxin during cold treatment, suggesting compensatory mechanisms to defend against reactive oxygen species are employed in the absence of microcystin in the mutant. Our observations highlight the potential selective advantages of a longer-term defensive strategy in management of oxidative stress (i.e., making microcystin) vs the shorter-term proactive strategy of producing cellular components to actively dissipate or degrade oxidative stress agents.
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Affiliation(s)
- Gwendolyn F Stark
- Department of Microbiology, The University of Tennessee, Knoxville, TN, USA
| | - Robbie M Martin
- Department of Microbiology, The University of Tennessee, Knoxville, TN, USA
| | - Laura E Smith
- Department of Microbiology, The University of Tennessee, Knoxville, TN, USA
| | - Bofan Wei
- Department of Chemistry, State University of New York College of Environmental Science and Forestry, Syracuse, NY, USA
| | - Ferdi L Hellweger
- Water Quality Engineering, Technical University of Berlin, Berlin, Germany
| | - George S Bullerjahn
- Department of Biological Sciences, Bowling Green State University, Bowling Green, OH, USA
| | - R Michael L McKay
- Great Lakes Institute for Environmental Research, The University of Windsor, Windsor, ON, Canada
| | - Gregory L Boyer
- Department of Chemistry, State University of New York College of Environmental Science and Forestry, Syracuse, NY, USA
| | - Steven W Wilhelm
- Department of Microbiology, The University of Tennessee, Knoxville, TN, USA
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4
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Heterotrophic Bacteria Dominate Catalase Expression during Microcystis Blooms. Appl Environ Microbiol 2022; 88:e0254421. [PMID: 35862723 PMCID: PMC9328184 DOI: 10.1128/aem.02544-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
In the oligotrophic oceans, key autotrophs depend on "helper" bacteria to reduce oxidative stress from hydrogen peroxide (H2O2) in the extracellular environment. H2O2 is also a ubiquitous stressor in freshwaters, but the effects of H2O2 on autotrophs and their interactions with bacteria are less well understood in freshwaters. Naturally occurring H2O2 in freshwater systems is proposed to impact the proportion of microcystin-producing (toxic) and non-microcystin-producing (nontoxic) Microcystis in blooms, which influences toxin concentrations and human health impacts. However, how different strains of Microcystis respond to naturally occurring H2O2 concentrations and the microbes responsible for H2O2 decomposition in freshwater cyanobacterial blooms are unknown. To address these knowledge gaps, we used metagenomics and metatranscriptomics to track the presence and expression of genes for H2O2 decomposition by microbes during a cyanobacterial bloom in western Lake Erie in the summer of 2014. katG encodes the key enzyme for decomposing extracellular H2O2 but was absent in most Microcystis cells. katG transcript relative abundance was dominated by heterotrophic bacteria. In axenic Microcystis cultures, an H2O2 scavenger (pyruvate) significantly improved growth rates of one toxic strain while other toxic and nontoxic strains were unaffected. These results indicate that heterotrophic bacteria play a key role in H2O2 decomposition in Microcystis blooms and suggest that their activity may affect the fitness of some Microcystis strains and thus the strain composition of Microcystis blooms but not along a toxic versus nontoxic dichotomy. IMPORTANCE Cyanobacterial harmful algal blooms (CHABs) threaten freshwater ecosystems globally through the production of toxins. Toxin production by cyanobacterial species and strains during CHABs varies widely over time and space, but the ecological drivers of the succession of toxin-producing species remain unclear. Hydrogen peroxide (H2O2) is ubiquitous in natural waters, inhibits microbial growth, and may determine the relative proportions of Microcystis strains during blooms. However, the mechanisms and organismal interactions involved in H2O2 decomposition are unexplored in CHABs. This study shows that some strains of bloom-forming freshwater cyanobacteria benefit from detoxification of H2O2 by associated heterotrophic bacteria, which may impact bloom development.
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5
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Dick GJ, Duhaime MB, Evans JT, Errera RM, Godwin CM, Kharbush JJ, Nitschky HS, Powers MA, Vanderploeg HA, Schmidt KC, Smith DJ, Yancey CE, Zwiers CC, Denef VJ. The genetic and ecophysiological diversity of Microcystis. Environ Microbiol 2021; 23:7278-7313. [PMID: 34056822 DOI: 10.1111/1462-2920.15615] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 05/24/2021] [Accepted: 05/27/2021] [Indexed: 01/30/2023]
Abstract
Microcystis is a cyanobacterium that forms toxic blooms in freshwater ecosystems around the world. Biological variation among taxa within the genus is apparent through genetic and phenotypic differences between strains and via the spatial and temporal distribution of strains in the environment, and this fine-scale diversity exerts strong influence over bloom toxicity. Yet we do not know how varying traits of Microcystis strains govern their environmental distribution, the tradeoffs and links between these traits, or how they are encoded at the genomic level. Here we synthesize current knowledge on the importance of diversity within Microcystis and on the genes and traits that likely underpin ecological differentiation of taxa. We briefly review spatial and environmental patterns of Microcystis diversity in the field and genetic evidence for cohesive groups within Microcystis. We then compile data on strain-level diversity regarding growth responses to environmental conditions and explore evidence for variation of community interactions across Microcystis strains. Potential links and tradeoffs between traits are identified and discussed. The resulting picture, while incomplete, highlights key knowledge gaps that need to be filled to enable new models for predicting strain-level dynamics, which influence the development, toxicity and cosmopolitan nature of Microcystis blooms.
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Affiliation(s)
- Gregory J Dick
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA.,Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Melissa B Duhaime
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Jacob T Evans
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Reagan M Errera
- National Oceanographic and Atmospheric Administration Great Lakes Environmental Research Lab, Ann Arbor, MI, USA
| | - Casey M Godwin
- School for Environment and Sustainability, Cooperative Institute for Great Lakes Research, University of Michigan, Ann Arbor, MI, USA
| | - Jenan J Kharbush
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Helena S Nitschky
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - McKenzie A Powers
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Henry A Vanderploeg
- National Oceanographic and Atmospheric Administration Great Lakes Environmental Research Lab, Ann Arbor, MI, USA
| | - Kathryn C Schmidt
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Derek J Smith
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Colleen E Yancey
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Claire C Zwiers
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Vincent J Denef
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
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6
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D'Agostino PM, Yeung ACY, Poljak A, David Waite T, Neilan BA. Comparative proteomics of the toxigenic diazotroph Raphidiopsis raciborskii (cyanobacteria) in response to iron. Environ Microbiol 2020; 23:405-414. [PMID: 33200490 DOI: 10.1111/1462-2920.15328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 11/13/2020] [Indexed: 11/30/2022]
Abstract
Raphidiopsis raciborskii is an invasive bloom-forming cyanobacteria with the flexibility to utilize atmospheric and fixed nitrogen. Since nitrogen-fixation has a high requirement for iron as an ezyme cofactor, we hypothesize that iron availability would determine the success of the species under nitrogen-fixing conditions. This study compares the proteomic response of cylindrospermopsin-producing and non-toxic strains of R. racibroskii to reduced iron concentrations, under nitrogen-fixing conditions, to examine any strain-specific adaptations that might increase fitness under these conditions. We also compared their proteomic responses at exponential and stationary growth phases to capture the changes throughout the growth cycle. Overall, the toxic strain was more competitive under Fe-starved conditions during exponential phase, with upregulated growth and transport-related proteins. The non-toxic strain showed reduced protein expression across multiple primary metabolism pathways. We propose that the increased expression of porin proteins during the exponential growth phase enables toxic strains to persist under Fe-starved conditions with this ability providing a potential explanation for the increased fitness of cylindrospermoipsin-producing strains during unfavourable environmental conditions.
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Affiliation(s)
- Paul M D'Agostino
- School of Biotechnology and Biomolecular Sciences, UNSW, Sydney, NSW, Australia.,Chair of Technical Biochemistry, Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Dresden, Germany
| | - Anna C Y Yeung
- School of Biotechnology and Biomolecular Sciences, UNSW, Sydney, NSW, Australia.,School of Civil and Environmental Engineering, UNSW, Sydney, NSW, Australia
| | - Anne Poljak
- Bioanalytical Mass Spectrometry Facility, UNSW, Sydney, NSW, Australia
| | - Trevor David Waite
- School of Civil and Environmental Engineering, UNSW, Sydney, NSW, Australia
| | - Brett A Neilan
- School of Biotechnology and Biomolecular Sciences, UNSW, Sydney, NSW, Australia.,School of Environmental and Life Sciences, University of Newcastle, Newcastle, NSW, Australia
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7
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Rao NRH, Granville AM, Wich PR, Henderson RK. Detailed algal extracellular carbohydrate-protein characterisation lends insight into algal solid-liquid separation process outcomes. WATER RESEARCH 2020; 178:115833. [PMID: 32339864 DOI: 10.1016/j.watres.2020.115833] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 04/04/2020] [Accepted: 04/13/2020] [Indexed: 06/11/2023]
Abstract
The effectiveness of algal solid-liquid separation processes has been impacted by the strong influence of algal extracellular organic matter (EOM), where the composition of proteins and carbohydrates and their associated interactions have been implicated. However, despite this, no studies have analysed the detailed protein and carbohydrate composition in EOM in relation to their impacts on separation. Hence, the aim of this study was to explore the relationship between the variety of carbohydrates and proteins present in the EOM of select algal and cyanobacterial samples and the associated separation performance to better understand the influence of specific biopolymers. The protein and carbohydrate composition of the EOM of three species - Microcystis aeruginosa CS-555/1, Chlorella vulgaris CS-42/7 and Microcystis aeruginosa CS-564/01, previously observed to result in variable treatment performance were investigated. The carbohydrates were analysed via high-performance anion-exchange chromatography (HPAEC) with pulsed amperometric detection (PAD) while the proteins were analysed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) combined with liquid chromatography-mass spectrometry (LC-MS). Ten unique monosaccharides were identified; of these, the greatest proportion of charged uronic acid carbohydrates were present in the EOM of M. aeruginosa CS-564/01. The protein profiling revealed that M. aeruginosa CS-564/01 had a greater proportion and concentration of proteins >75 kDa when compared to M. aeruginosa CS-555/1 or C. vulgaris CS-42/7. It was determined that three serine- and two threonine-based proteins, detected in greater concentrations in M. aeruginosa CS-564/01 than CS-555/1, could covalently interact with carbohydrates (OHenderson et al., 2010a, 2010b-linked glycosylation). These proteins have the ability to form numerous localised networks with carbohydrates and cells in the presence of coagulant molecules, thereby providing a good hypothesis to explain the excellent treatment performance observed for M. aeruginosa CS-564/01 previously. It is proposed that the uronic acids in M. aeruginosa CS-564/01 could interact with proteins via glycosylation, explaining why the coagulant demand for this strain remained low despite the high charged carbohydrate concentration. Overall, it is proposed that process performance could be impacted by: (a) physicochemical characteristics and (b) carbohydrate-protein interactions.
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Affiliation(s)
- N R H Rao
- Algae and Organic Matter Laboratory (AOM Lab), School of Chemical Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia; Centre for Advanced Macromolecular Design (CAMD), School of Chemical Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - A M Granville
- Centre for Advanced Macromolecular Design (CAMD), School of Chemical Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - P R Wich
- Centre for Advanced Macromolecular Design (CAMD), School of Chemical Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - R K Henderson
- Algae and Organic Matter Laboratory (AOM Lab), School of Chemical Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia.
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8
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Romeu MJL, Domínguez-Pérez D, Almeida D, Morais J, Campos A, Vasconcelos V, Mergulhão FJM. Characterization of planktonic and biofilm cells from two filamentous cyanobacteria using a shotgun proteomic approach. BIOFOULING 2020; 36:631-645. [PMID: 32715767 DOI: 10.1080/08927014.2020.1795141] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 07/02/2020] [Accepted: 07/06/2020] [Indexed: 06/11/2023]
Abstract
Cyanobacteria promote marine biofouling with significant impacts. A qualitative proteomic analysis, by LC-MS/MS, of planktonic and biofilm cells from two cyanobacteria was performed. Biofilms were formed on glass and perspex at two relevant hydrodynamic conditions for marine environments (average shear rates of 4 s-1 and 40 s-1). For both strains and surfaces, biofilm development was higher at 4 s-1. Biofilm development of Nodosilinea sp. LEGE 06145 was substantially higher than Nodosilinea sp. LEGE 06119, but no significant differences were found between surfaces. Overall, 377 and 301 different proteins were identified for Nodosilinea sp. LEGE 06145 and Nodosilinea sp. LEGE 06119. Differences in protein composition were more noticeable in biofilms formed under different hydrodynamic conditions than in those formed on different surfaces. Ribosomal and photosynthetic proteins were identified in most conditions. The characterization performed gives new insights into how shear rate and surface affect the planktonic to biofilm transition, from a structural and proteomics perspective.
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Affiliation(s)
- Maria João Leal Romeu
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, Porto, Portugal
| | - Dany Domínguez-Pérez
- CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Matosinhos, Portugal
| | - Daniela Almeida
- CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Matosinhos, Portugal
| | - João Morais
- CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Matosinhos, Portugal
| | - Alexandre Campos
- CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Matosinhos, Portugal
| | - Vítor Vasconcelos
- CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Matosinhos, Portugal
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, Porto, Portugal
| | - Filipe J M Mergulhão
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, Porto, Portugal
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9
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Weiss G, Kovalerchick D, Lieman-Hurwitz J, Murik O, De Philippis R, Carmeli S, Sukenik A, Kaplan A. Increased algicidal activity of Aeromonas veronii in response to Microcystis aeruginosa: interspecies crosstalk and secondary metabolites synergism. Environ Microbiol 2020; 21:1140-1150. [PMID: 30761715 DOI: 10.1111/1462-2920.14561] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Revised: 01/31/2019] [Accepted: 02/09/2019] [Indexed: 12/16/2022]
Abstract
Toxic Microcystis spp. blooms constitute a serious threat to water quality worldwide. Aeromonas veronii was isolated from Microcystis sp. colonies collected in Lake Kinneret. Spent Aeromonas media inhibits the growth of Microcystis aeruginosa MGK isolated from Lake Kinneret. The inhibition was much stronger when Aeromonas growth medium contained spent media from MGK suggesting that Aeromonas recognized its presence and produced secondary metabolites that inhibit Microcystis growth. Fractionations of the crude extract and analyses of the active fractions identified several secondary metabolites including lumichrome in Aeromonas media. Application of lumichrome at concentrations as low as 4 nM severely inhibited Microcystis growth. Inactivation of aviH in the lumichrome biosynthetic pathway altered the lumichrome level in Aeromonas and the extent of MGK growth inhibition. Conversely, the initial lag in Aeromonas growth was significantly longer when provided with Microcystis spent media but Aeromonas was able to resume normal growth. The longer was pre-exposure to Microcystis spent media the shorter was the lag phase in Aeromonas growth indicating the presence of, and acclimation to, secondary MGK metabolite(s) the nature of which was not revealed. Our study may help to control toxic Microcystis blooms taking advantage of chemical languages used in the interspecies communication.
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Affiliation(s)
- Gad Weiss
- Plants and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 9190401, Israel
| | - Dimitry Kovalerchick
- Raymond and Beverly Sackler School of Chemistry and Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, 69978, Israel.,Plants and Environmental Sciences, Metabomed Ltd, Yavne, 81220, Israel
| | - Judy Lieman-Hurwitz
- Plants and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 9190401, Israel
| | - Omer Murik
- Plants and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 9190401, Israel
| | - Roberto De Philippis
- Department of Agricultural, Food, Environmental and Forestry Sciences and Technologies (DAGRI), University of Florence, 50144, Florence, Italy
| | - Shmuel Carmeli
- Raymond and Beverly Sackler School of Chemistry and Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Assaf Sukenik
- Plants and Environmental Sciences, The Yigal Allon Kinneret Limnological Laboratory, Israel Oceanographic and Limnological Research, Migdal, Israel
| | - Aaron Kaplan
- Plants and Environmental Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 9190401, Israel
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10
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Jacinavicius FR, Pacheco ABF, Chow F, Verissimo da Costa GC, Kalume DE, Rigonato J, Schmidt EC, Sant'Anna CL. Different ecophysiological and structural strategies of toxic and non-toxic Microcystis aeruginosa (cyanobacteria) strains assessed under culture conditions. ALGAL RES 2019. [DOI: 10.1016/j.algal.2019.101548] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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11
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Guedes IA, Pacheco ABF, Vilar MCP, Mello MM, Marinho MM, Lurling M, Azevedo SMFO. Intraspecific variability in response to phosphorus depleted conditions in the cyanobacteria Microcystis aeruginosa and Raphidiopsis raciborskii. HARMFUL ALGAE 2019; 86:96-105. [PMID: 31358281 DOI: 10.1016/j.hal.2019.03.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 02/18/2019] [Accepted: 03/14/2019] [Indexed: 06/10/2023]
Abstract
Phosphorus loading plays an important role in the occurrence of cyanobacterial blooms and understanding how this nutrient affects the physiology of cyanobacteria is imperative to manage these phenomena. Microcystis aeruginosa and Raphidiopsis raciborskii are cyanobacterial species that form potentially toxic blooms in freshwater ecosystems worldwide. Blooms comprise numerous strains with high trait variability, which can contribute to the widespread distribution of these species. Here, we explored the intraspecific variability in response to phosphorus depleted conditions (P-) testing five strains of each species. Strains could be differentiated by cell volume or genetic profiles except for those of the same species, sampling location and date, though these presented differences in their response to (P-). Although differently affected by (P-) over 10 days, all strains were able to grow and maintain photosynthetic activity. For most M. aeruginosa and R. raciborskii strains growth rates were not significantly different comparing (P+) and (P-) conditions. After ten days in (P-), only one M. aeruginosa strain and two R. raciborskii strains showed reduction in biovolume yield as compared to (P+) but in most strains chlorophyll-a concentrations were lower in (P-) than in (P+). Reduced photosystem II efficiency was found for only one R. raciborskii strain while all M. aeruginosa strains were affected. Only two M. aeruginosa and one R. raciborskii strain increased alkaline phosphatase activity under (P-) as compared to (P+). Variation in P-uptake was also observed but comparison among strains yielded homogeneous groups comprised of representatives of both species. Comparing the response of each species as a whole, the (P-) condition affected growth rate, biovolume yield and chlorophyll yield. However, these parameters revealed variation among strains of the same species to the extent that differences between M. aeruginosa and R. raciborskii were not significant. Taken together, these results do not support the idea that R. raciborskii, as a species, can withstand phosphorus limitation better than M. aeruginosa and also point that the level of intraspecific variation may preclude generalizations based on studies that use only one or few strains.
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Affiliation(s)
- Iame Alves Guedes
- Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro 21949-902, Brazil
| | - Ana Beatriz F Pacheco
- Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro 21949-902, Brazil
| | - Mauro C P Vilar
- Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro 21949-902, Brazil
| | - Mariana M Mello
- Federal University of Juiz de Fora, Juiz de Fora, MG 36036-900, Brazil
| | - Marcelo Manzi Marinho
- Laboratory of Ecology and Physiology of Phytoplankton, Department of Plant Biology, University of Rio de Janeiro State, Rua São Francisco Xavier 524-PHLC Sala 511a, 20550-900, Rio de Janeiro, Brazil
| | - Miquel Lurling
- Aquatic Ecology & Water Quality Management Group, Department of Environmental Sciences, Wageningen University, P.O. Box 47, 6700 AA, Wageningen, the Netherlands; Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6700 AB, Wageningen, the Netherlands
| | - Sandra M F O Azevedo
- Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro 21949-902, Brazil.
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12
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Liu T, Mazmouz R, Pearson LA, Neilan BA. Mutagenesis of the Microcystin Tailoring and Transport Proteins in a Heterologous Cyanotoxin Expression System. ACS Synth Biol 2019; 8:1187-1194. [PMID: 31042359 DOI: 10.1021/acssynbio.9b00068] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The microcystins are a large group of cyclic peptide hepatotoxins produced by several genera of freshwater cyanobacteria. The genes responsible for microcystin biosynthesis are encoded within a large (∼55 kbp) gene cluster, mcyA-J. The recent establishment of a cyanotoxin heterologous expression system in Escherichia coli has provided the means to study microcystin biosynthesis in a genetically tractable, rapidly growing host. Using this system, we demonstrate that deletion of the ABC-transporter, mcyH, and dehydrogenase, mcyI, abolishes microcystin production, while deletion of the O-methyltransferase, mcyJ, results in the production of the demethylated (DM) toxin [d-Asp3, DMAdda5]microcystin-LR. Both methylated and DM toxin variants were heterologously produced at high titers and efficiently exported into the extracellular medium, enabling easy purification. The results show that the mcy gene cluster can be engineered in E. coli to study the function of its individual components and direct the synthesis of particular microcystin variants. This technology could potentially be applied to other natural products of ecological and biomedical significance.
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Affiliation(s)
- Tianzhe Liu
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, NSW 2052, Sydney, Australia
| | - Rabia Mazmouz
- School of Environmental and Life Sciences, The University of Newcastle, NSW 2308, Callaghan, Australia
| | - Leanne A. Pearson
- School of Environmental and Life Sciences, The University of Newcastle, NSW 2308, Callaghan, Australia
| | - Brett A. Neilan
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, NSW 2052, Sydney, Australia
- School of Environmental and Life Sciences, The University of Newcastle, NSW 2308, Callaghan, Australia
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13
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Shishido TK, Jokela J, Humisto A, Suurnäkki S, Wahlsten M, Alvarenga DO, Sivonen K, Fewer DP. The Biosynthesis of Rare Homo-Amino Acid Containing Variants of Microcystin by a Benthic Cyanobacterium. Mar Drugs 2019; 17:md17050271. [PMID: 31067786 PMCID: PMC6562525 DOI: 10.3390/md17050271] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/02/2019] [Accepted: 05/05/2019] [Indexed: 02/05/2023] Open
Abstract
Microcystins are a family of chemically diverse hepatotoxins produced by distantly related cyanobacteria and are potent inhibitors of eukaryotic protein phosphatases 1 and 2A. Here we provide evidence for the biosynthesis of rare variants of microcystin that contain a selection of homo-amino acids by the benthic cyanobacterium Phormidium sp. LP904c. This strain produces at least 16 microcystin chemical variants many of which contain homophenylalanine or homotyrosine. We retrieved the complete 54.2 kb microcystin (mcy) gene cluster from a draft genome assembly. Analysis of the substrate specificity of McyB1 and McyC adenylation domain binding pockets revealed divergent substrate specificity sequences, which could explain the activation of homo-amino acids which were present in 31% of the microcystins detected and included variants such as MC-LHty, MC-HphHty, MC-LHph and MC-HphHph. The mcy gene cluster did not encode enzymes for the synthesis of homo-amino acids but may instead activate homo-amino acids produced during the synthesis of anabaenopeptins. We observed the loss of microcystin during cultivation of a closely related strain, Phormidium sp. DVL1003c. This study increases the knowledge of benthic cyanobacterial strains that produce microcystin variants and broadens the structural diversity of known microcystins.
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Affiliation(s)
- Tânia Keiko Shishido
- Department of Microbiology, University of Helsinki, Viikinkaari 9, FI-0014 Helsinki, Finland.
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Viikinkaari 5D, FI-0014 Helsinki, Finland.
| | - Jouni Jokela
- Department of Microbiology, University of Helsinki, Viikinkaari 9, FI-0014 Helsinki, Finland.
| | - Anu Humisto
- Department of Microbiology, University of Helsinki, Viikinkaari 9, FI-0014 Helsinki, Finland.
| | - Suvi Suurnäkki
- Department of Microbiology, University of Helsinki, Viikinkaari 9, FI-0014 Helsinki, Finland.
- Department of Biological and Environmental Science, University of Jyväskylä, FI-40014 Jyväskylä, Finland.
| | - Matti Wahlsten
- Department of Microbiology, University of Helsinki, Viikinkaari 9, FI-0014 Helsinki, Finland.
| | - Danillo O Alvarenga
- Department of Microbiology, University of Helsinki, Viikinkaari 9, FI-0014 Helsinki, Finland.
| | - Kaarina Sivonen
- Department of Microbiology, University of Helsinki, Viikinkaari 9, FI-0014 Helsinki, Finland.
| | - David P Fewer
- Department of Microbiology, University of Helsinki, Viikinkaari 9, FI-0014 Helsinki, Finland.
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14
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Zhou Y, Zhang X, Li X, Jia P, Dai R. Evaluation of changes in Microcystis aeruginosa growth and microcystin production by urea via transcriptomic surveys. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 655:181-187. [PMID: 30469064 DOI: 10.1016/j.scitotenv.2018.11.100] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 11/02/2018] [Accepted: 11/07/2018] [Indexed: 06/09/2023]
Abstract
The freshwater cyanobacteria, Microcystis aeruginosa (M. aeruginosa), is well known to produce microcystins (MCs) and induce the formation of harmful algal blooms (HABs) in aquatic environments, but the effects that urea fertilizer has on cyanobacterial growth and toxin production from a molecular biology perspective remain poorly understood. We evaluated changes in the growth and toxicity of M. aeruginosa cultured under different conditions of nitrogen (N) starvation (NN), low nitrogen (LN), and high nitrogen (HN). Cell density and chlorophyll-a concentrations decreased in cyanobacteria exposed to N starvation and increased following the addition of urea, whereas MCs content increased to a peak and then decreased after urea addition. Transcriptomic analysis confirmed that most genes encoding MCs and genes involved in N metabolic pathways were upregulated under N starvation and LN conditions, whereas these genes were downregulated under HN conditions. Our results offer important insights into the exploring N in controlling the formation of HABs and toxin production based on both physiological and molecular response.
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Affiliation(s)
- Yanping Zhou
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Xufeng Zhang
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Xuan Li
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Peili Jia
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Ruihua Dai
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China.
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15
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Qu J, Shen L, Zhao M, Li W, Jia C, Zhu H, Zhang Q. Determination of the Role of Microcystis aeruginosa in Toxin Generation Based on Phosphoproteomic Profiles. Toxins (Basel) 2018; 10:toxins10070304. [PMID: 30041444 PMCID: PMC6070999 DOI: 10.3390/toxins10070304] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 07/12/2018] [Accepted: 07/17/2018] [Indexed: 01/06/2023] Open
Abstract
Microcystis aeruginosa is the most common species responsible for toxic cyanobacterial blooms and is considered a significant contributor to the production of cyanotoxins, particularly the potent liver toxins called microcystins. Numerous studies investigating Microcystis spp. blooms have revealed their deleterious effects in freshwater environments. However, the available knowledge regarding the global phosphoproteomics of M. aeruginosa and their regulatory roles in toxin generation is limited. In this study, we conducted comparative phosphoproteomic profiling of non-toxic and toxin-producing strains of M. aeruginosa. We identified 59 phosphorylation sites in 37 proteins in a non-toxic strain and 26 phosphorylation sites in 18 proteins in a toxin-producing strain. The analysis of protein phosphorylation abundances and functions in redox homeostasis, energy metabolism, light absorption and photosynthesis showed marked differences between the non-toxic and toxin-producing strains of M. aeruginosa, indicating that these processes are strongly related to toxin generation. Moreover, the protein-protein interaction results indicated that BJ0JVG8 can directly interact with the PemK-like toxin protein B0JQN8. Thus, the phosphorylation of B0JQN8 appears to be associated with the regulatory roles of toxins in physiological activity.
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Affiliation(s)
- Jiangqi Qu
- Beijing Key Laboratory of Fishery Biotechnology, Beijing Fisheries Research Institute, Beijing 100068, China.
| | - Liping Shen
- State key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China.
| | - Meng Zhao
- Beijing Key Laboratory of Fishery Biotechnology, Beijing Fisheries Research Institute, Beijing 100068, China.
| | - Wentong Li
- Beijing Key Laboratory of Fishery Biotechnology, Beijing Fisheries Research Institute, Beijing 100068, China.
| | - Chengxia Jia
- Beijing Key Laboratory of Fishery Biotechnology, Beijing Fisheries Research Institute, Beijing 100068, China.
| | - Hua Zhu
- Beijing Key Laboratory of Fishery Biotechnology, Beijing Fisheries Research Institute, Beijing 100068, China.
| | - Qingjing Zhang
- Beijing Key Laboratory of Fishery Biotechnology, Beijing Fisheries Research Institute, Beijing 100068, China.
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16
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Nitrogen limitation, toxin synthesis potential, and toxicity of cyanobacterial populations in Lake Okeechobee and the St. Lucie River Estuary, Florida, during the 2016 state of emergency event. PLoS One 2018; 13:e0196278. [PMID: 29791446 PMCID: PMC5965861 DOI: 10.1371/journal.pone.0196278] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 04/10/2018] [Indexed: 11/19/2022] Open
Abstract
Lake Okeechobee, FL, USA, has been subjected to intensifying cyanobacterial blooms that can spread to the adjacent St. Lucie River and Estuary via natural and anthropogenically-induced flooding events. In July 2016, a large, toxic cyanobacterial bloom occurred in Lake Okeechobee and throughout the St. Lucie River and Estuary, leading Florida to declare a state of emergency. This study reports on measurements and nutrient amendment experiments performed in this freshwater-estuarine ecosystem (salinity 0–25 PSU) during and after the bloom. In July, all sites along the bloom exhibited dissolved inorganic nitrogen-to-phosphorus ratios < 6, while Microcystis dominated (> 95%) phytoplankton inventories from the lake to the central part of the estuary. Chlorophyll a and microcystin concentrations peaked (100 and 34 μg L-1, respectively) within Lake Okeechobee and decreased eastwards. Metagenomic analyses indicated that genes associated with the production of microcystin (mcyE) and the algal neurotoxin saxitoxin (sxtA) originated from Microcystis and multiple diazotrophic genera, respectively. There were highly significant correlations between levels of total nitrogen, microcystin, and microcystin synthesis gene abundance across all surveyed sites (p < 0.001), suggesting high levels of nitrogen supported the production of microcystin during this event. Consistent with this, experiments performed with low salinity water from the St. Lucie River during the event indicated that algal biomass was nitrogen-limited. In the fall, densities of Microcystis and concentrations of microcystin were significantly lower, green algae co-dominated with cyanobacteria, and multiple algal groups displayed nitrogen-limitation. These results indicate that monitoring and regulatory strategies in Lake Okeechobee and the St. Lucie River and Estuary should consider managing loads of nitrogen to control future algal and microcystin-producing cyanobacterial blooms.
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17
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Banerjee S, Subramanian A, Chattopadhyay J, Sarkar RR. Exploring the role of GS-GOGAT cycle in microcystin synthesis and regulation - a model based analysis. MOLECULAR BIOSYSTEMS 2017; 13:2603-2614. [PMID: 29034927 DOI: 10.1039/c7mb00342k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Toxic cyanobacteria blooms populate water bodies by consuming external nutrients and releasing cyanotoxins that are detrimental for other aquatic species, producing a significant impact on the plankton ecosystem and food web. To exercise population-level control of toxin production, understanding the biochemical mechanisms that explain cyanotoxin regulation within a bacterial cell is of utmost importance. In this study, we explore the mechanistic events to investigate the dependence of toxin microcystin on external nitrogen, a known regulator of the toxin, and for the first time, propose a kinetic model that analyzes the intracellular conditions required to ensure nitrogen dependence on microcystin. We hypothesize that the GS-GOGAT cycle is manipulated by variable influx of different intracellular metabolites that can either disturb or promote the balance between the enzyme microcystin synthetase and substrate glutamate to produce variable microcystin levels. As opposed to the popular notion that nitrogen starvation increases microcystin synthesis, our analyses suggest that under certain intracellular metabolite regimes, this relationship can either be completely lost or reversed. External nitrogen can only complement the conditions fixed by intracellular glutamate, glutamine and 2-oxoglutarate. This mechanistic understanding can provide an experimentally testable hypothesis for exploring the less-known biology of microcystin synthesis and designing specific interventions.
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Affiliation(s)
- Swarnendu Banerjee
- Agricultural and Ecological Research Unit, Indian Statistical Institute, 203, B. T. Road, Kolkata 700108, India
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18
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Park JH, Jin JH, Ji IJ, An HJ, Kim JW, Lee GM. Proteomic analysis of host cell protein dynamics in the supernatant of Fc-fusion protein-producing CHO DG44 and DUKX-B11 cell lines in batch and fed-batch cultures. Biotechnol Bioeng 2017. [DOI: 10.1002/bit.26360] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Jin Hyoung Park
- Department of Biological Sciences; KAIST; 291 Daehak-ro, Yuseong-gu Daejeon 34141 Republic of Korea
| | - Jong Hwa Jin
- New Drug Development Center; Cheongju-si Chungbuk Republic of Korea
| | - In Jung Ji
- Graduate School of Analytical Science & Technology; Chungnam National University; Daejon Republic of Korea
| | - Hyun Joo An
- Graduate School of Analytical Science & Technology; Chungnam National University; Daejon Republic of Korea
| | - Jong Won Kim
- New Drug Development Center; Cheongju-si Chungbuk Republic of Korea
| | - Gyun Min Lee
- Department of Biological Sciences; KAIST; 291 Daehak-ro, Yuseong-gu Daejeon 34141 Republic of Korea
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19
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Ceballos-Laita L, Marcuello C, Lostao A, Calvo-Begueria L, Velazquez-Campoy A, Bes MT, Fillat MF, Peleato ML. Microcystin-LR Binds Iron, and Iron Promotes Self-Assembly. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:4841-4850. [PMID: 28368104 DOI: 10.1021/acs.est.6b05939] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The microcystin-producing Microcystis aeruginosa PCC 7806 and its close strain, the nonproducing Microcystis aeruginosa PCC 7005, grow similarly in the presence of 17 μM iron. Under severe iron deficient conditions (0.05 μM), the toxigenic strain grows slightly less than in iron-replete conditions, while the nonproducing microcystin strain is not able to grow. Isothermal titration calorimetry performed at cyanobacterial cytosol or meaningful environmental pHs values shows a microcystin-LR dissociaton constant for Fe2+ and Fe3+ of 2.4 μM. Using atomic force microscopy, 40% of microcystin-LR dimers were observed, and the presence of iron promoted its oligomerization up to six units. Microcystin-LR binds also Mo6+, Cu2+, and Mn2+. Polymeric microcystin binding iron may be related with a toxic cell colony advantage, providing enhanced iron bioavailability and perhaps affecting the structure of the gelatinous sheath. Inside cells, with microcystin implicated in the fitness of the photosynthetic machinery under stress conditions, the toxin would be involved in avoiding metal-dependent Fenton reactions when photooxidation causes disassembly of the iron-rich photosystems. Additionally, it could be hypothesized that polymerization-depolymerization dynamics may be an additional signal that could trigger changes (for example, in the binding of microcystin to proteins).
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Affiliation(s)
- Laura Ceballos-Laita
- Institute for Biocomputation and Physics of Complex Systems (BIFI)-Joint Unit BIFI-IQFR (CSIC) , Aragón 50018, Spain
| | | | | | - Laura Calvo-Begueria
- Institute for Biocomputation and Physics of Complex Systems (BIFI)-Joint Unit BIFI-IQFR (CSIC) , Aragón 50018, Spain
| | - Adrián Velazquez-Campoy
- Institute for Biocomputation and Physics of Complex Systems (BIFI)-Joint Unit BIFI-IQFR (CSIC) , Aragón 50018, Spain
| | - María Teresa Bes
- Institute for Biocomputation and Physics of Complex Systems (BIFI)-Joint Unit BIFI-IQFR (CSIC) , Aragón 50018, Spain
| | - María F Fillat
- Institute for Biocomputation and Physics of Complex Systems (BIFI)-Joint Unit BIFI-IQFR (CSIC) , Aragón 50018, Spain
| | - María-Luisa Peleato
- Institute for Biocomputation and Physics of Complex Systems (BIFI)-Joint Unit BIFI-IQFR (CSIC) , Aragón 50018, Spain
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20
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Park JH, Jin JH, Lim MS, An HJ, Kim JW, Lee GM. Proteomic Analysis of Host Cell Protein Dynamics in the Culture Supernatants of Antibody-Producing CHO Cells. Sci Rep 2017; 7:44246. [PMID: 28281648 PMCID: PMC5345005 DOI: 10.1038/srep44246] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 02/06/2017] [Indexed: 12/21/2022] Open
Abstract
Chinese hamster ovary (CHO) cells are the most common cell line used for the production of therapeutic proteins including monoclonal antibodies (mAbs). Host cell proteins (HCPs), secreted and released from lysed cells, accumulate extracellularly during the cultures of recombinant CHO (rCHO) cells, potentially impairing product quality. In an effort to maintain good mAb quality during the cultures, HCPs accumulated extracellularly in batch and fed-batch cultures of a mAb-producing rCHO cell line were identified and quantified by nanoflow liquid chromatography-tandem mass spectrometry, followed by their gene ontology and functional analysis. Due to higher cell concentration and longer culture duration, more HCPs were identified and quantitated in fed-batch culture (2145 proteins identified and 1673 proteins quantified) than in batch culture (1934 proteins identified and 1486 proteins quantified). Clustering analysis of HCPs showed that the concentration profiles of HCPs affecting mAb quality (Lgmn, Ctsd, Gbl1, and B4galt1) correlated with changes in mAb quality attributes such as aggregation, charge variants, and N-glycosylation during the cultures. Taken together, the dataset of HCPs obtained in this study provides insights into determining the appropriate target proteins to be removed during both the cultures and purification steps for ensuring good mAb quality.
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Affiliation(s)
- Jin Hyoung Park
- Department of Biological Sciences, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Jong Hwa Jin
- New Drug Development Center, 123 Osongsaengmyeng-ro, Cheongju-si, Chungbuk 28160, Republic of Korea
| | - Myung Sin Lim
- New Drug Development Center, 123 Osongsaengmyeng-ro, Cheongju-si, Chungbuk 28160, Republic of Korea
| | - Hyun Joo An
- Graduate School of Analytical Science &Technology, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejon 34134, Republic of Korea
| | - Jong Won Kim
- New Drug Development Center, 123 Osongsaengmyeng-ro, Cheongju-si, Chungbuk 28160, Republic of Korea
| | - Gyun Min Lee
- Department of Biological Sciences, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
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21
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Scherer PI, Raeder U, Geist J, Zwirglmaier K. Influence of temperature, mixing, and addition of microcystin-LR on microcystin gene expression in Microcystis aeruginosa. Microbiologyopen 2017; 6:e00393. [PMID: 27411372 PMCID: PMC5300888 DOI: 10.1002/mbo3.393] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Revised: 06/22/2016] [Accepted: 06/23/2016] [Indexed: 01/01/2023] Open
Abstract
Cyanobacteria, such as the toxin producer Microcystis aeruginosa, are predicted to be favored by global warming both directly, through elevated water temperatures, and indirectly, through factors such as prolonged stratification of waterbodies. M. aeruginosa is able to produce the hepatotoxin microcystin, which causes great concern in freshwater management worldwide. However, little is known about the expression of microcystin synthesis genes in response to climate change-related factors. In this study, a new RT-qPCR assay employing four reference genes (GAPDH, gltA, rpoC1, and rpoD) was developed to assess the expression of two target genes (the microcystin synthesis genes mcyB and mcyD). This assay was used to investigate changes in mcyB and mcyD expression in response to selected environmental factors associated with global warming. A 10°C rise in temperature significantly increased mcyB expression, but not mcyD expression. Neither mixing nor the addition of microcystin-LR (10 μg L-1 or 60 μg L-1 ) significantly altered mcyB and mcyD expression. The expression levels of mcyB and mcyD were correlated but not identical.
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Affiliation(s)
- Pia I. Scherer
- Aquatic Systems Biology UnitLimnological Research Station IffeldorfDepartment of Ecology and Ecosystem ManagementTechnical University of MunichMunichGermany
| | - Uta Raeder
- Aquatic Systems Biology UnitLimnological Research Station IffeldorfDepartment of Ecology and Ecosystem ManagementTechnical University of MunichMunichGermany
| | - Juergen Geist
- Aquatic Systems Biology UnitLimnological Research Station IffeldorfDepartment of Ecology and Ecosystem ManagementTechnical University of MunichMunichGermany
| | - Katrin Zwirglmaier
- Aquatic Systems Biology UnitLimnological Research Station IffeldorfDepartment of Ecology and Ecosystem ManagementTechnical University of MunichMunichGermany
- Present address: Bundeswehr Institute of MicrobiologyMunichGermany
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22
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Microcystin Biosynthesis and mcyA Expression in Geographically Distinct Microcystis Strains under Different Nitrogen, Phosphorus, and Boron Regimes. BIOMED RESEARCH INTERNATIONAL 2016; 2016:5985987. [PMID: 27803926 PMCID: PMC5075592 DOI: 10.1155/2016/5985987] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 09/01/2016] [Indexed: 02/04/2023]
Abstract
Roles of nutrients and other environmental variables in development of cyanobacterial bloom and its toxicity are complex and not well understood. We have monitored the photoautotrophic growth, total microcystin concentration, and microcystins synthetase gene (mcyA) expression in lab-grown strains of Microcystis NIES 843 (reference strain), KW (Wangsong Reservoir, South Korea), and Durgakund (Varanasi, India) under different nutrient regimes (nitrogen, phosphorus, and boron). Higher level of nitrogen and boron resulted in increased growth (avg. 5 and 6.5 Chl a mg/L, resp.), total microcystin concentrations (avg. 1.185 and 7.153 mg/L, resp.), and mcyA transcript but its expression was not directly correlated with total microcystin concentrations in the target strains. Interestingly, Durgakund strain had much lower microcystin content and lacked microcystin-YR variant over NIES 843 and KW. It is inferred that microcystin concentration and its variants are strain specific. We have also examined the heterotrophic bacteria associated with cyanobacterial bloom in Durgakund Pond and Wangsong Reservoir which were found to be enriched in Alpha-, Beta-, and Gammaproteobacteria and that could influence the bloom dynamics.
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23
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Russo DA, Couto N, Beckerman AP, Pandhal J. A Metaproteomic Analysis of the Response of a Freshwater Microbial Community under Nutrient Enrichment. Front Microbiol 2016; 7:1172. [PMID: 27536273 PMCID: PMC4971099 DOI: 10.3389/fmicb.2016.01172] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 07/14/2016] [Indexed: 11/25/2022] Open
Abstract
Eutrophication can lead to an uncontrollable increase in algal biomass, which has repercussions for the entire microbial and pelagic community. Studies have shown how nutrient enrichment affects microbial species succession, however details regarding the impact on community functionality are rare. Here, we applied a metaproteomic approach to investigate the functional changes to algal and bacterial communities, over time, in oligotrophic and eutrophic conditions, in freshwater microcosms. Samples were taken early during algal and cyanobacterial dominance and later under bacterial dominance. 1048 proteins, from the two treatments and two timepoints, were identified and quantified by their exponentially modified protein abundance index. In oligotrophic conditions, Bacteroidetes express extracellular hydrolases and Ton-B dependent receptors to degrade and transport high molecular weight compounds captured while attached to the phycosphere. Alpha- and Beta-proteobacteria were found to capture different substrates from algal exudate (carbohydrates and amino acids, respectively) suggesting resource partitioning to avoid direct competition. In eutrophic conditions, environmental adaptation proteins from cyanobacteria suggested better resilience compared to algae in a low carbon nutrient enriched environment. This study provides insight into differences in functional microbial processes between oligo- and eutrophic conditions at different timepoints and highlights how primary producers control bacterial resources in freshwater environments. The data have been deposited to the ProteomeXchange with identifier PXD004592.
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Affiliation(s)
- David A Russo
- Department of Chemical and Biological Engineering, University of Sheffield Sheffield, UK
| | - Narciso Couto
- Department of Chemical and Biological Engineering, University of Sheffield Sheffield, UK
| | - Andrew P Beckerman
- Department of Animal and Plant Sciences, University of Sheffield Sheffield, UK
| | - Jagroop Pandhal
- Department of Chemical and Biological Engineering, University of Sheffield Sheffield, UK
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24
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Paerl HW, Otten TG, Joyner AR. Moving towards adaptive management of cyanotoxin-impaired water bodies. Microb Biotechnol 2016; 9:641-51. [PMID: 27418325 PMCID: PMC4993183 DOI: 10.1111/1751-7915.12383] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 06/23/2016] [Indexed: 11/30/2022] Open
Abstract
The cyanobacteria are a phylum of bacteria that have played a key role in shaping the Earth's biosphere due to their pioneering ability to perform oxygenic photosynthesis. Throughout their history, cyanobacteria have experienced major biogeochemical changes accompanying Earth's geochemical evolution over the past 2.5+ billion years, including periods of extreme climatic change, hydrologic, nutrient and radiation stress. Today, they remain remarkably successful, exploiting human nutrient over‐enrichment as nuisance “blooms.” Cyanobacteria produce an array of unique metabolites, the functions and biotic ramifications of which are the subject of diverse ecophysiological studies. These metabolites are relevant from organismal and ecosystem function perspectives because some can be toxic and fatal to diverse biota, including zooplankton and fish consumers of algal biomass, and high‐level consumers of aquatic food sources and drinking water, including humans. Given the long history of environmental extremes and selection pressures that cyanobacteria have experienced, it is likely that that these toxins serve ecophysiological functions aimed at optimizing growth and fitness during periods of environmental stress. Here, we explore the molecular and ecophysiological mechanisms underlying cyanotoxin production, with emphasis on key environmental conditions potentially controlling toxin production. Based on this information, we offer potential management strategies for reducing cyanotoxin potentials in natural waters; for cyanotoxins with no clear drivers yet elucidated, we highlight the data gaps and research questions that are still lacking. We focus on the four major classes of toxins (anatoxins, cylindrospermopsins, microcystins and saxitoxins) that have thus far been identified as relevant from environmental health perspectives, but caution there may be other harmful metabolites waiting to be elucidated.
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Affiliation(s)
- Hans W Paerl
- Institute of Marine Sciences, University of North Carolina at Chapel Hill, Morehead City, NC, USA
| | - Timothy G Otten
- Bend Genetics, LLC, 87 Scripps Drive, Ste. 301, Sacramento, CA, USA
| | - Alan R Joyner
- Institute of Marine Sciences, University of North Carolina at Chapel Hill, Morehead City, NC, USA
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25
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Harke MJ, Steffen MM, Gobler CJ, Otten TG, Wilhelm SW, Wood SA, Paerl HW. A review of the global ecology, genomics, and biogeography of the toxic cyanobacterium, Microcystis spp. HARMFUL ALGAE 2016; 54:4-20. [PMID: 28073480 DOI: 10.1016/j.hal.2015.12.007] [Citation(s) in RCA: 514] [Impact Index Per Article: 64.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 12/22/2015] [Indexed: 05/03/2023]
Abstract
This review summarizes the present state of knowledge regarding the toxic, bloom-forming cyanobacterium, Microcystis, with a specific focus on its geographic distribution, toxins, genomics, phylogeny, and ecology. A global analysis found documentation suggesting geographic expansion of Microcystis, with recorded blooms in at least 108 countries, 79 of which have also reported the hepatatoxin microcystin. The production of microcystins (originally "Fast-Death Factor") by Microcystis and factors that control synthesis of this toxin are reviewed, as well as the putative ecophysiological roles of this metabolite. Molecular biological analyses have provided significant insight into the ecology and physiology of Microcystis, as well as revealed the highly dynamic, and potentially unstable, nature of its genome. A genetic sequence analysis of 27 Microcystis species, including 15 complete/draft genomes are presented. Using the strictest biological definition of what constitutes a bacterial species, these analyses indicate that all Microcystis species warrant placement into the same species complex since the average nucleotide identity values were above 95%, 16S rRNA nucleotide identity scores exceeded 99%, and DNA-DNA hybridization was consistently greater than 70%. The review further provides evidence from around the globe for the key role that both nitrogen and phosphorus play in controlling Microcystis bloom dynamics, and the effect of elevated temperature on bloom intensification. Finally, highlighted is the ability of Microcystis assemblages to minimize their mortality losses by resisting grazing by zooplankton and bivalves, as well as viral lysis, and discuss factors facilitating assemblage resilience.
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Affiliation(s)
- Matthew J Harke
- Department of Earth and Environmental Sciences, Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, United States
| | - Morgan M Steffen
- James Madison University, Department of Biology, 951 Carrier Dr., Harrisonburg, VA 22807, United States.
| | - Christopher J Gobler
- Stony Brook University, School of Marine and Atmospheric Sciences, 239 Montauk Hwy, Southampton, NY 11968, United States
| | - Timothy G Otten
- Oregon State University, Department of Microbiology, Nash Hall 226, Corvallis, OR 97331, United States
| | - Steven W Wilhelm
- University of Tennessee, Department of Microbiology, 1414 West Cumberland Ave., Knoxville, TN 37996, United States
| | - Susanna A Wood
- Cawthron Institute, Private Bag 2, Nelson, New Zealand and Environmental Research Institute, University of Waikato, Hamilton, New Zealand
| | - Hans W Paerl
- University of North Carolina at Chapel Hill, Institute of Marine Sciences, 3431 Arendell Street, Morehead City, NC 28557, United States
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26
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D'Agostino PM, Woodhouse JN, Makower AK, Yeung ACY, Ongley SE, Micallef ML, Moffitt MC, Neilan BA. Advances in genomics, transcriptomics and proteomics of toxin-producing cyanobacteria. ENVIRONMENTAL MICROBIOLOGY REPORTS 2016; 8:3-13. [PMID: 26663762 DOI: 10.1111/1758-2229.12366] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 11/10/2015] [Accepted: 12/05/2015] [Indexed: 06/05/2023]
Abstract
A common misconception persists that the genomes of toxic and non-toxic cyanobacterial strains are largely conserved with the exception of the presence or absence of the genes responsible for toxin production. Implementation of -omics era technologies has challenged this paradigm, with comparative analyses providing increased insight into the differences between strains of the same species. The implementation of genomic, transcriptomic and proteomic approaches has revealed distinct profiles between toxin-producing and non-toxic strains. Further, metagenomics and metaproteomics highlight the genomic potential and functional state of toxic bloom events over time. In this review, we highlight how these technologies have shaped our understanding of the complex relationship between these molecules, their producers and the environment at large within which they persist.
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Affiliation(s)
- Paul M D'Agostino
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Biological Sciences Building D26, Sydney, NSW, 2052, Australia
| | - Jason N Woodhouse
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Biological Sciences Building D26, Sydney, NSW, 2052, Australia
| | - A Katharina Makower
- Department of Microbiology, Institute for Biochemistry and Biology, University of Potsdam, Potsdam-Golm, 14476, Germany
| | - Anna C Y Yeung
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Biological Sciences Building D26, Sydney, NSW, 2052, Australia
| | - Sarah E Ongley
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Biological Sciences Building D26, Sydney, NSW, 2052, Australia
| | - Melinda L Micallef
- School of Science and Health, University of Western Sydney, Sydney, NSW, 2571, Australia
| | - Michelle C Moffitt
- School of Science and Health, University of Western Sydney, Sydney, NSW, 2571, Australia
| | - Brett A Neilan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Biological Sciences Building D26, Sydney, NSW, 2052, Australia
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Microbial communities reflect temporal changes in cyanobacterial composition in a shallow ephemeral freshwater lake. ISME JOURNAL 2015; 10:1337-51. [PMID: 26636552 DOI: 10.1038/ismej.2015.218] [Citation(s) in RCA: 128] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 09/28/2015] [Accepted: 10/08/2015] [Indexed: 01/19/2023]
Abstract
The frequency of freshwater cyanobacterial blooms is at risk of increasing as a consequence of climate change and eutrophication of waterways. It is increasingly apparent that abiotic data are insufficient to explain variability within the cyanobacterial community, with biotic factors such as heterotrophic bacterioplankton, viruses and protists emerging as critical drivers. During the Australian summer of 2012-2013, a bloom that occurred in a shallow ephemeral lake over a 6-month period was comprised of 22 distinct cyanobacteria, including Microcystis, Dolichospermum, Oscillatoria and Sphaerospermopsis. Cyanobacterial cell densities, bacterial community composition and abiotic parameters were assessed over this period. Alpha-diversity indices and multivariate analysis were successful at differentiating three distinct bloom phases and the contribution of abiotic parameters to each. Network analysis, assessing correlations between biotic and abiotic variables, reproduced these phases and assessed the relative importance of both abiotic and biotic factors. Variables possessing elevated betweeness centrality included temperature, sodium and operational taxonomic units belonging to the phyla Verrucomicrobia, Planctomyces, Bacteroidetes and Actinobacteria. Species-specific associations between cyanobacteria and bacterioplankton, including the free-living Actinobacteria acI, Bacteroidetes, Betaproteobacteria and Verrucomicrobia, were also identified. We concluded that changes in the abundance and nature of freshwater cyanobacteria are associated with changes in the diversity and composition of lake bacterioplankton. Given this, an increase in the frequency of cyanobacteria blooms has the potential to alter nutrient cycling and contribute to long-term functional perturbation of freshwater systems.
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Alexova R, Dang TC, Fujii M, Raftery MJ, Waite TD, Ferrari BC, Neilan BA. Specific global responses to N and Fe nutrition in toxic and non-toxicMicrocystis aeruginosa. Environ Microbiol 2015; 18:401-13. [DOI: 10.1111/1462-2920.12958] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 06/05/2015] [Accepted: 06/15/2015] [Indexed: 01/03/2023]
Affiliation(s)
- Ralitza Alexova
- School of Biotechnology and Biomolecular Sciences; University of New South Wales; Sydney NSW 2052 Australia
| | - The Cuong Dang
- School of Civil and Environmental Engineering; University of New South Wales; Sydney NSW 2052 Australia
| | - Manabu Fujii
- School of Civil and Environmental Engineering; University of New South Wales; Sydney NSW 2052 Australia
- Department of Civil Engineering; Tokyo Institute of Technology; 2-12-1-M1-4 Ookayama Tokyo 152-8552 Japan
| | - Mark J. Raftery
- Bioanalytical Mass Spectrometry Facility; University of New South Wales; Sydney NSW 2052 Australia
| | - T. David Waite
- School of Civil and Environmental Engineering; University of New South Wales; Sydney NSW 2052 Australia
| | - Belinda C. Ferrari
- School of Biotechnology and Biomolecular Sciences; University of New South Wales; Sydney NSW 2052 Australia
- Australian Centre for Astrobiology; University of New South Wales; Sydney NSW 2052 Australia
| | - Brett A. Neilan
- School of Biotechnology and Biomolecular Sciences; University of New South Wales; Sydney NSW 2052 Australia
- Australian Centre for Astrobiology; University of New South Wales; Sydney NSW 2052 Australia
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Beversdorf LJ, Miller TR, McMahon KD. Long-term monitoring reveals carbon-nitrogen metabolism key to microcystin production in eutrophic lakes. Front Microbiol 2015; 6:456. [PMID: 26029192 PMCID: PMC4428211 DOI: 10.3389/fmicb.2015.00456] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 04/27/2015] [Indexed: 02/04/2023] Open
Abstract
The environmental drivers contributing to cyanobacterial dominance in aquatic systems have been extensively studied. However, understanding of toxic vs. non-toxic cyanobacterial population dynamics and the mechanisms regulating cyanotoxin production remain elusive, both physiologically and ecologically. One reason is the disconnect between laboratory and field-based studies. Here, we combined 3 years of temporal data, including microcystin (MC) concentrations, 16 years of long-term ecological research, and 10 years of molecular data to investigate the potential factors leading to the selection of toxic Microcystis and MC production. Our analysis revealed that nitrogen (N) speciation and inorganic carbon (C) availability might be important drivers of Microcystis population dynamics and that an imbalance in cellular C: N ratios may trigger MC production. More specifically, precipitous declines in ammonium concentrations lead to a transitional period of N stress, even in the presence of high nitrate concentrations, that we call the “toxic phase.” Following the toxic phase, temperature and cyanobacterial abundance remained elevated but MC concentrations drastically declined. Increases in ammonium due to lake turnover may have led to down regulation of MC synthesis or a shift in the community from toxic to non-toxic species. While total phosphorus (P) to total N ratios were relatively low over the time-series, MC concentrations were highest when total N to total P ratios were also highest. Similarly, high C: N ratios were also strongly correlated to the toxic phase. We propose a metabolic model that corroborates molecular studies and reflects our ecological observations that C and N metabolism may regulate MC production physiologically and ecologically. In particular, we hypothesize that an imbalance between 2-oxoglutarate and ammonium in the cell regulates MC synthesis in the environment.
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Affiliation(s)
- Lucas J Beversdorf
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison Madison, WI, USA ; Joseph J. Zilber School of Public Health, University of Wisconsin-Milwaukee Milwaukee, WI, USA
| | - Todd R Miller
- Joseph J. Zilber School of Public Health, University of Wisconsin-Milwaukee Milwaukee, WI, USA
| | - Katherine D McMahon
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison Madison, WI, USA ; Department of Bacteriology, University of Wisconsin-Madison Madison, WI, USA
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Transcriptomics-aided dissection of the intracellular and extracellular roles of microcystin in Microcystis aeruginosa PCC 7806. Appl Environ Microbiol 2014; 81:544-54. [PMID: 25381232 DOI: 10.1128/aem.02601-14] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recent studies have provided evidence for both intracellular and extracellular roles of the potent hepatotoxin microcystin (MC) in the bloom-forming cyanobacterium Microcystis. Here, we surveyed transcriptomes of the wild-type strain M. aeruginosa PCC 7806 and the microcystin-deficient ΔmcyB mutant under low light conditions with and without the addition of external MC of the LR variant (MC-LR). Transcriptomic data acquired by microarray and quantitative PCR revealed substantial differences in the relative expression of genes of the central intermediary metabolism, photosynthesis, and energy metabolism. In particular, the data provide evidence for a lower photosystem I (PSI)-to-photosystem II (PSII) ratio and a more pronounced carbon limitation in the microcystin-deficient mutant. Interestingly, only 6% of the transcriptional differences could be complemented by external microcystin-LR addition. This MC signaling effect was seen exclusively for genes of the secondary metabolism category. The orphan polyketide synthase gene cluster IPF38-51 was specifically downregulated in response to external MC-LR under low light. Our data suggest a hierarchical and light-dependent cross talk of secondary metabolites and support both an intracellular and an extracellular role of MC in Microcystis.
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31
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Microcystin production and regulation under nutrient stress conditions in toxic microcystis strains. Appl Environ Microbiol 2014; 80:5836-43. [PMID: 25038094 DOI: 10.1128/aem.01009-14] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microcystin is a common and well-known cyanobacterial toxin whose intracellular role is still under investigation. Increasing knowledge on microcystin gene expression and regulation can contribute to the understanding of its putative cellular function. In this work, reverse transcription-quantitative PCR (RT-qPCR) was used to investigate the transcriptional response of the mcyD gene to nitrogen (nitrate and ammonium) and phosphorus limitation in two toxic Microcystis strains. The existence of a direct correlation between transcripts of mcyD and ntcA genes was also identified. In previous studies, NtcA (global nitrogen regulator) has been described as a potential component in the control of microcystin biosynthesis. This research showed that stress agents linked to nutrient deprivation could lead to a significant increase of microcystin production in both strains studied. The more toxic strain proved to be more resistant to nutrient limitation. The similar outcomes of mcyD regulation observed for all nutrients suggest that this response can be linked to oxidative stress of cells undergoing adverse growth conditions.
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Boopathi T, Ki JS. Impact of environmental factors on the regulation of cyanotoxin production. Toxins (Basel) 2014; 6:1951-78. [PMID: 24967641 PMCID: PMC4113735 DOI: 10.3390/toxins6071951] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 06/06/2014] [Accepted: 06/17/2014] [Indexed: 11/25/2022] Open
Abstract
Cyanobacteria are capable of thriving in almost all environments. Recent changes in climatic conditions due to increased human activities favor the occurrence and severity of harmful cyanobacterial bloom all over the world. Knowledge of the regulation of cyanotoxins by the various environmental factors is essential for effective management of toxic cyanobacterial bloom. In recent years, progress in the field of molecular mechanisms involved in cyanotoxin production has paved the way for assessing the role of various factors on the cyanotoxin production. In this review, we present an overview of the influence of various environmental factors on the production of major group of cyanotoxins, including microcystins, nodularin, cylindrospermopsin, anatoxins and saxitoxins.
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Affiliation(s)
| | - Jang-Seu Ki
- Department of Life Science, Sangmyung University, Seoul 110-743, Korea.
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33
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Gehringer MM, Wannicke N. Climate change and regulation of hepatotoxin production in Cyanobacteria. FEMS Microbiol Ecol 2014; 88:1-25. [PMID: 24490596 DOI: 10.1111/1574-6941.12291] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 01/20/2014] [Accepted: 01/20/2014] [Indexed: 01/04/2023] Open
Abstract
Harmful, bloom-forming cyanobacteria (CyanoHABs) are occurring with increasing regularity in freshwater and marine ecosystems. The most commonly occurring cyanobacterial toxins are the hepatotoxic microcystin and nodularin. These cyclic hepta- and pentapeptides are synthesised nonribosomally by the gene products of the toxin gene clusters mcy and nda, respectively. Understanding of the regulation of hepatotoxin production is incomplete, although there is strong evidence supporting the roles of iron, light, higher nitrate availability and inorganic carbon in modulating microcystin levels. The majority of these studies have focused on the unicellular freshwater, microcystin-producing strain of Microcystis aeruginosa, with little attention being paid to terrestrial or marine toxin producers. This review intends to investigate the regulation of microcystin and nodularin production in unicellular and filamentous diazotrophic cyanobacteria against the background of changing climate conditions. Special focus is given to diazotrophic filamentous cyanobacteria, for example Nodularia spumigena, capable of regulating their nitrogen levels by actively fixing dinitrogen. By combining data from significant studies, an overall scheme of the regulation of toxin production is presented, focussing specifically on nodularin production in diazotrophs against the background of increasing carbon dioxide concentrations and temperatures envisaged under current climate change models. Furthermore, the risk of sustaining and spreading CyanoHABs in the future ocean is evaluated.
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Affiliation(s)
- Michelle M Gehringer
- Department of Plant Ecology and Systematics, Technical University of Kaiserslautern, Kaiserslautern, Germany
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34
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D'Agostino PM, Song X, Neilan BA, Moffitt MC. Comparative proteomics reveals that a saxitoxin-producing and a nontoxic strain of Anabaena circinalis are two different ecotypes. J Proteome Res 2014; 13:1474-84. [PMID: 24460188 DOI: 10.1021/pr401007k] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
In Australia, saxitoxin production is restricted to the cyanobacterial species Anabaena circinalis and is strain-dependent. We aimed to characterize a saxitoxin-producing and nontoxic strain of A. circinalis at the proteomic level using iTRAQ. Seven proteins putatively involved in saxitoxin biosynthesis were identified within our iTRAQ experiment for the first time. The proteomic profile of the toxic A. circinalis was significantly different from the nontoxic strain, indicating that each is likely to inhabit a unique ecological niche. Under control growth conditions, the saxitoxin-producing A. circinalis displayed a higher abundance of photosynthetic, carbon fixation and nitrogen metabolic proteins. Differential abundance of these proteins suggests a higher intracellular C:N ratio and a higher concentration of intracellular 2-oxoglutarate in our toxic strain compared with the nontoxic strain. This may be a novel site for posttranslational regulation because saxitoxin biosynthesis putatively requires a 2-oxoglutarate-dependent dioxygenase. The nontoxic A. circinalis was more abundant in proteins, indicating cellular stress. Overall, our study has provided the first insight into fundamental differences between a toxic and nontoxic strain of A. circinalis, indicating that they are distinct ecotypes.
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Affiliation(s)
- Paul M D'Agostino
- School of Science and Health, University of Western Sydney , Campbelltown, NSW 2560, Australia
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35
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Sinha R, Pearson LA, Davis TW, Muenchhoff J, Pratama R, Jex A, Burford MA, Neilan BA. Comparative genomics of Cylindrospermopsis raciborskii strains with differential toxicities. BMC Genomics 2014; 15:83. [PMID: 24476316 PMCID: PMC3922686 DOI: 10.1186/1471-2164-15-83] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 01/14/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cylindrospermopsis raciborskii is an invasive filamentous freshwater cyanobacterium, some strains of which produce toxins. Sporadic toxicity may be the result of gene deletion events, the horizontal transfer of toxin biosynthesis gene clusters, or other genomic variables, yet the evolutionary drivers for cyanotoxin production remain a mystery. Through examining the genomes of toxic and non-toxic strains of C. raciborskii, we hoped to gain a better understanding of the degree of similarity between these strains of common geographical origin, and what the primary differences between these strains might be. Additionally, we hoped to ascertain why some cyanobacteria possess the cylindrospermopsin biosynthesis (cyr) gene cluster and produce toxin, while others do not. It has been hypothesised that toxicity or lack thereof might confer a selective advantage to cyanobacteria under certain environmental conditions. RESULTS In order to examine the fundamental differences between toxic and non-toxic C. raciborskii strains, we sequenced the genomes of two closely related isolates, CS-506 (CYN+) and CS-509 (CYN-) sourced from different lakes in tropical Queensland, Australia. These genomes were then compared to a third (reference) genome from C. raciborskii CS-505 (CYN+). Genome sizes were similar across all three strains and their G + C contents were almost identical. At least 2,767 genes were shared among all three strains, including the taxonomically important rpoc1, ssuRNA, lsuRNA, cpcA, cpcB, nifB and nifH, which exhibited 99.8-100% nucleotide identity. Strains CS-506 and CS-509 contained at least 176 and 101 strain-specific (or non-homologous) genes, respectively, most of which were associated with DNA repair and modification, nutrient uptake and transport, or adaptive measures such as osmoregulation. However, the only significant genetic difference observed between the two strains was the presence or absence of the cylindrospermopsin biosynthesis gene cluster. Interestingly, we also identified a cryptic secondary metabolite gene cluster in strain CS-509 (CYN-) and a second cryptic cluster common to CS-509 and the reference strain, CS-505 (CYN+). CONCLUSIONS Our results confirm that the most important factor contributing to toxicity in C. raciborskii is the presence or absence of the cyr gene cluster. We did not identify any other distally encoded genes or gene clusters that correlate with CYN production. The fact that the additional genomic differences between toxic and non-toxic strains were primarily associated with stress and adaptation genes suggests that CYN production may be linked to these physiological processes.
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Affiliation(s)
- Rati Sinha
- School of Biotechnology and Bimolecular Sciences, University of New South Wales, 2052 Sydney, NSW, Australia
| | - Leanne A Pearson
- School of Biotechnology and Bimolecular Sciences, University of New South Wales, 2052 Sydney, NSW, Australia
| | - Timothy W Davis
- Australian Rivers Institute, Griffith University, 4111 Nathan, Queensland, Australia
| | - Julia Muenchhoff
- School of Biotechnology and Bimolecular Sciences, University of New South Wales, 2052 Sydney, NSW, Australia
| | - Ryanbi Pratama
- School of Biotechnology and Bimolecular Sciences, University of New South Wales, 2052 Sydney, NSW, Australia
| | - Aaron Jex
- Faculty of Veterinary Science, University of Melbourne, Melbourne, Victoria, Australia
| | - Michele A Burford
- Australian Rivers Institute, Griffith University, 4111 Nathan, Queensland, Australia
| | - Brett A Neilan
- School of Biotechnology and Bimolecular Sciences, University of New South Wales, 2052 Sydney, NSW, Australia
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Rai S, Agrawal C, Shrivastava AK, Singh PK, Rai LC. Comparative proteomics unveils cross species variations in Anabaena under salt stress. J Proteomics 2014; 98:254-70. [PMID: 24406298 DOI: 10.1016/j.jprot.2013.12.020] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 12/04/2013] [Accepted: 12/12/2013] [Indexed: 11/28/2022]
Abstract
UNLABELLED The present study compares protein diversity within three Anabaena species (Anabaena doliolum, Anabaena sp.PCC 7120 and Anabaena L31). 2-DE based analysis of 256 protein spots in control and 1, 3, 5, and 7days of salt treatment resulted into 96 proteins arching across fourteen functional categories were assigned to biochemical pathways using KOBAS 2.0. While 52.34% of the evaluated protein spots were common across three species, the remaining 47.66% fraction mainly comprised of the hypothetical and unknown proteins. PSORTb, CDD, Motifscan and Pfam revealed function and subcellular localization for 27 of the 31 hypothetical and unknown proteins. The differences in high salt tolerance (LC50) of A. doliolum over A. L31 was reflected by (i) many fold accumulation (as spot volumes) of Alr3090, Alr0803, peptidyl prolyl cis-trans isomerase and modulator of DNA gyrase proteins, and (ii) a better photosynthesis and energy homeostasis as indicated through photosystem activity, respiration, ATP and NADPH contents. Some common noteworthy salt effects include (i) photosystem damage, (ii) DNA damage repair, (iii) upregulated protein synthesis, (iv) enhanced sulphur metabolism, and (v) upregulated pentose phosphate pathway. 34 of the identified protein spots are novel entries to the Anabaena salt proteome. This study reveals the existence of separate strategies even within species to combat stress. BIOLOGICAL SIGNIFICANCE This study for the first time enumerates protein diversity in three Anabaena species employing their presence/absence and relative abundance. Proteomics integrated with physiology and bioinformatics deciphers differential salt tolerance among the studied species and is the first of its kind to predict the function of hypothetical and unknown proteins. Salt-induced proteomic alterations clearly demonstrate significant metabolic shifts and existence of separate molecular phenome among the species investigated. This may be responsible for niche specificity limiting their application as biofertilizer. Of the 96 identified proteins, a large chunk are new entries to the Anabaena salt proteome while some protein genes may be used as potential candidates for engineering salt tolerant cyanobacteria.
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Affiliation(s)
- Snigdha Rai
- Molecular Biology Section, Laboratory of Algal Biology, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi 221005, India
| | - Chhavi Agrawal
- Molecular Biology Section, Laboratory of Algal Biology, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi 221005, India
| | - Alok Kumar Shrivastava
- Molecular Biology Section, Laboratory of Algal Biology, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi 221005, India
| | - Prashant Kumar Singh
- Molecular Biology Section, Laboratory of Algal Biology, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi 221005, India
| | - L C Rai
- Molecular Biology Section, Laboratory of Algal Biology, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi 221005, India.
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Heat shock transcriptional responses in an MC-Producing Cyanobacterium (Planktothrix agardhii) and its MC-deficient mutant under high light conditions. PLoS One 2013; 8:e73198. [PMID: 24023831 PMCID: PMC3762838 DOI: 10.1371/journal.pone.0073198] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 07/17/2013] [Indexed: 01/26/2023] Open
Abstract
Microcystins (MCs) are the most commonly-reported hepatotoxins produced by various cyanobacterial taxa in fresh waters to constitute a potential threat to human and animal health. The biological role of MCs in the producer organisms is not known, and it would be very useful to understand the driving force behind the toxin production. Recent studies have suggested that MCs may have a protective function in cells facing environmental stress. Following this starting premise, we speculate that under adverse conditions the expression of stress-related genes coding for Heat Shock Proteins (Hsp) might be different in an MC-producing strain and its MC-deficient mutant. We therefore used RT-qPCR to compare the expression of 13 hsp genes of an MC-producing strain of Planktothrix agardhii (CYA126/8) and its MC-deficient ΔmcyD mutant over different periods of exposure to high light stress (HL). Three reference genes (RGs) were selected from six candidates to normalize the RT-qPCR data. Of these three RGs (rsh, rpoD, and gltA), gltA is used here for the first time as an RG in prokaryotes. Under HL stress, five genes were found to be strongly up-regulated in both strains (htpG, dnaK, hspA, groES, and groEL). Unexpectedly, we found that the MC-producing wild type strain accumulated higher levels of htpG and dnaK transcripts in response to HL stress than the MC-deficient mutant. In addition, a significant increase in the mcyE transcript was detected in the mutant, suggesting that MCs are required under HL conditions. We discuss several possible roles of MCs in the response to HL stress through their possible involvement in the protective mechanisms of the cells.
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38
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Holland A, Kinnear S. Interpreting the possible ecological role(s) of cyanotoxins: compounds for competitive advantage and/or physiological aide? Mar Drugs 2013; 11:2239-58. [PMID: 23807545 PMCID: PMC3736421 DOI: 10.3390/md11072239] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 05/14/2013] [Accepted: 05/29/2013] [Indexed: 11/26/2022] Open
Abstract
To date, most research on freshwater cyanotoxin(s) has focused on understanding the dynamics of toxin production and decomposition, as well as evaluating the environmental conditions that trigger toxin production, all with the objective of informing management strategies and options for risk reduction. Comparatively few research studies have considered how this information can be used to understand the broader ecological role of cyanotoxin(s), and the possible applications of this knowledge to the management of toxic blooms. This paper explores the ecological, toxicological, and genetic evidence for cyanotoxin production in natural environments. The possible evolutionary advantages of toxin production are grouped into two main themes: That of "competitive advantage" or "physiological aide". The first grouping illustrates how compounds produced by cyanobacteria may have originated from the need for a cellular defence mechanism, in response to grazing pressure and/or resource competition. The second grouping considers the contribution that secondary metabolites make to improved cellular physiology, through benefits to homeostasis, photosynthetic efficiencies, and accelerated growth rates. The discussion also includes other factors in the debate about possible evolutionary roles for toxins, such as different modes of exposures and effects on non-target (i.e., non-competitive) species. The paper demonstrates that complex and multiple factors are at play in driving evolutionary processes in aquatic environments. This information may provide a fresh perspective on managing toxic blooms, including the need to use a "systems approach" to understand how physico-chemical conditions, as well biological stressors, interact to trigger toxin production.
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Affiliation(s)
- Aleicia Holland
- Centre for Environmental Management, Central Queensland University, Bruce Highway, Rockhampton, QLD 4700, Australia.
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Beversdorf LJ, Miller TR, McMahon KD. The role of nitrogen fixation in cyanobacterial bloom toxicity in a temperate, eutrophic lake. PLoS One 2013; 8:e56103. [PMID: 23405255 PMCID: PMC3566065 DOI: 10.1371/journal.pone.0056103] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Accepted: 01/09/2013] [Indexed: 11/26/2022] Open
Abstract
Toxic cyanobacterial blooms threaten freshwaters worldwide but have proven difficult to predict because the mechanisms of bloom formation and toxin production are unknown, especially on weekly time scales. Water quality management continues to focus on aggregated metrics, such as chlorophyll and total nutrients, which may not be sufficient to explain complex community changes and functions such as toxin production. For example, nitrogen (N) speciation and cycling play an important role, on daily time scales, in shaping cyanobacterial communities because declining N has been shown to select for N fixers. In addition, subsequent N pulses from N2 fixation may stimulate and sustain toxic cyanobacterial growth. Herein, we describe how rapid early summer declines in N followed by bursts of N fixation have shaped cyanobacterial communities in a eutrophic lake (Lake Mendota, Wisconsin, USA), possibly driving toxic Microcystis blooms throughout the growing season. On weekly time scales in 2010 and 2011, we monitored the cyanobacterial community in a eutrophic lake using the phycocyanin intergenic spacer (PC-IGS) region to determine population dynamics. In parallel, we measured microcystin concentrations, N2 fixation rates, and potential environmental drivers that contribute to structuring the community. In both years, cyanobacterial community change was strongly correlated with dissolved inorganic nitrogen (DIN) concentrations, and Aphanizomenon and Microcystis alternated dominance throughout the pre-toxic, toxic, and post-toxic phases of the lake. Microcystin concentrations increased a few days after the first significant N2 fixation rates were observed. Then, following large early summer N2 fixation events, Microcystis increased and became most abundant. Maximum microcystin concentrations coincided with Microcystis dominance. In both years, DIN concentrations dropped again in late summer, and N2 fixation rates and Aphanizomenon abundance increased before the lake mixed in the fall. Estimated N inputs from N2 fixation were large enough to supplement, or even support, the toxic Microcystis blooms.
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Affiliation(s)
- Lucas J Beversdorf
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
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Da Rós PC, Silva CS, Silva-Stenico ME, Fiore MF, de Castro HF. Microcystis aeruginosa lipids as feedstock for biodiesel synthesis by enzymatic route. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.molcatb.2012.04.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Fan F, Nie S, Dammer EB, Duong DM, Pan D, Ping L, Zhai L, Wu J, Hong X, Qin L, Xu P, Zhang YH. Protein Profiling of Active Cysteine Cathepsins in Living Cells Using an Activity-Based Probe Containing a Cell-Penetrating Peptide. J Proteome Res 2012; 11:5763-72. [DOI: 10.1021/pr300575u] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Fengkai Fan
- Britton Chance Center for Biomedical
Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology (HUST),
Wuhan, China
- Key Laboratory of Biomedical
Photonics of Ministry of Education, Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan,
China
| | - Si Nie
- Britton Chance Center for Biomedical
Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology (HUST),
Wuhan, China
- Key Laboratory of Biomedical
Photonics of Ministry of Education, Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan,
China
| | - Eric B. Dammer
- Department of Human Genetics,
and Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, United States
| | - Duc M. Duong
- Department of Human Genetics,
and Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, United States
| | - Deng Pan
- Britton Chance Center for Biomedical
Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology (HUST),
Wuhan, China
- Key Laboratory of Biomedical
Photonics of Ministry of Education, Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan,
China
| | - Lingyan Ping
- State Key Laboratory of Proteomics,
Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing, China
- Department of Biochemistry,
School of Medicine, Wuhan University, Wuhan,
China
| | - Linhui Zhai
- State Key Laboratory of Proteomics,
Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing, China
- Key Laboratory of Combinatorial
Biosynthesis and Drug Discovery, Wuhan University, Ministry of Education, and Wuhan University School of Pharmaceutical
Sciences, Wuhan, China
| | - Junzhu Wu
- Department of Biochemistry,
School of Medicine, Wuhan University, Wuhan,
China
| | - Xuechuan Hong
- Key Laboratory of Combinatorial
Biosynthesis and Drug Discovery, Wuhan University, Ministry of Education, and Wuhan University School of Pharmaceutical
Sciences, Wuhan, China
| | - Lingsong Qin
- Britton Chance Center for Biomedical
Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology (HUST),
Wuhan, China
- Key Laboratory of Biomedical
Photonics of Ministry of Education, Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan,
China
| | - Ping Xu
- State Key Laboratory of Proteomics,
Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing, China
- Key Laboratory of Combinatorial
Biosynthesis and Drug Discovery, Wuhan University, Ministry of Education, and Wuhan University School of Pharmaceutical
Sciences, Wuhan, China
| | - Yu-Hui Zhang
- Britton Chance Center for Biomedical
Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology (HUST),
Wuhan, China
- Key Laboratory of Biomedical
Photonics of Ministry of Education, Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan,
China
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Tonietto A, Petriz BA, Araújo WC, Mehta A, Magalhães BS, Franco OL. Comparative proteomics between natural Microcystis isolates with a focus on microcystin synthesis. Proteome Sci 2012; 10:38. [PMID: 22676507 PMCID: PMC3522533 DOI: 10.1186/1477-5956-10-38] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Accepted: 05/09/2012] [Indexed: 11/10/2022] Open
Abstract
UNLABELLED BACKGROUND Microcystis aeruginosa is a species of cyanobacteria commonly found in a number of countries and frequently related to animal poisoning episodes due to its capacity to produce the cyanotoxin known as microcystin. Despite vast literature on microcystin structures and their deleterious effects, little is known about its synthesis by cyanobacteria. Therefore, this study used proteomic tools to compare two M. aeruginosa strains, contrasting them for microcystin production. RESULTS 2-DE gels were performed and 30 differential protein spots were chosen. Among them, 11 protein spots were unique in the toxin producing strain and 8 in the non-toxin producing strain, and 14 protein spots were shown on both 2-DE gels but expressed differently in intensity. Around 57% of the tandem mass spectrometry identified proteins were related to energy metabolism, with these proteins being up-regulated in the toxin producing strain. CONCLUSIONS These data suggest that the presence of higher quantities of metabolic enzymes could be related to microcystin metabolism in comparison to the non-toxin producing strain. Moreover, it was suggested that the production of microcystin could also be related to other proteins than those directly involved in its production, such as the enzymes involved in the Calvin cycle and glycolysis.
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Affiliation(s)
- Angela Tonietto
- Centro de Análises Proteômicas e Bioquímicas, Universidade Católica de Brasília, Pós Graduação em Ciências Genômicas e Biotecnologia, SGAN 916 Norte Av, W5, Brasília, DF, Brazil.
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Kaplan A, Harel M, Kaplan-Levy RN, Hadas O, Sukenik A, Dittmann E. The languages spoken in the water body (or the biological role of cyanobacterial toxins). Front Microbiol 2012; 3:138. [PMID: 22529842 PMCID: PMC3328848 DOI: 10.3389/fmicb.2012.00138] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2012] [Accepted: 03/23/2012] [Indexed: 11/13/2022] Open
Abstract
Although intensification of toxic cyanobacterial blooms over the last decade is a matter of growing concern due to bloom impact on water quality, the biological role of most of the toxins produced is not known. In this critical review we focus primarily on the biological role of two toxins, microcystins and cylindrospermopsin, in inter- and intra-species communication and in nutrient acquisition. We examine the experimental evidence supporting some of the dogmas in the field and raise several open questions to be dealt with in future research. We do not discuss the health and environmental implications of toxin presence in the water body.
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Affiliation(s)
- Aaron Kaplan
- Department of Plant and Environmental Sciences, The Hebrew University of Jerusalem Jerusalem, Israel.
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Neilan BA, Pearson LA, Muenchhoff J, Moffitt MC, Dittmann E. Environmental conditions that influence toxin biosynthesis in cyanobacteria. Environ Microbiol 2012; 15:1239-53. [PMID: 22429476 DOI: 10.1111/j.1462-2920.2012.02729.x] [Citation(s) in RCA: 186] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Over the past 15 years, the genetic basis for production of many cyanobacterial bioactive compounds has been described. This knowledge has enabled investigations into the environmental factors that regulate the production of these toxins at the molecular level. Such molecular or systems level studies are also likely to reveal the physiological role of the toxin and contribute to effective water resource management. This review focuses on the environmental regulation of some of the most relevant cyanotoxins, namely the microcystins, nodularin, cylindrospermopsin, saxitoxins, anatoxins and jamaicamides.
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Affiliation(s)
- Brett A Neilan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia.
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