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Ugya AY, Yan C, Chen H, Wang Q. Unravelling the eco-monitoring potential of phytoplankton towards a sustainable aquatic ecosystem. MARINE POLLUTION BULLETIN 2025; 216:118021. [PMID: 40253974 DOI: 10.1016/j.marpolbul.2025.118021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2025] [Revised: 04/17/2025] [Accepted: 04/17/2025] [Indexed: 04/22/2025]
Abstract
Phytoplankton play an integral role in primary production in aquatic ecosystems, thus butressing its function as an important tool for pollution indication and water quality assessment. Their response mechanism towards the changes in nutrient levels and environmental conditions makes them valuable indicators of ecosystem health. The driver of this response is a complex molecular mechanism involving gene expression and metabolic pathways that allow microalgae to adapt and thrive in varying conditions. The current study shows how phytoplankton population and functional trait dynamics can serve as early signs of potential environmental stressors impacting aquatic ecosystems. This study is highly significant because it highlights the role of phytoplankton as sensitive and reliable bioindicators of aquatic ecosystem health. Thus, providing valuable information for monitoring and managing water quality in marine environments. Also, the study will provide a unique insight into understanding the impact of pollution on phytoplankton, which can also help inform conservation efforts to protect vulnerable species and ecosystems. The study linked the bioindicator role of phytoplankton to a complex molecular mechanisms involving alterations in gene expression, activation of stress-related signalling pathways, and shifts in metabolic profiles. These responses are often characterised by the production of reactive oxygen species (ROS), the upregulation of antioxidant defence systems, and modifications in lipid, protein, and pigment synthesis. The progress of the application of phytoplankton for biomonitoring has been hindered by issues such as sensitivity to multiple environmental variables, diversity of phytoplankton species, and complexity of community interactions. This challenge can be averted through the development of advanced monitoring techniques that can accurately detect and quantify toxins in real time.
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Affiliation(s)
- Adamu Yunusa Ugya
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China; Henan Key Laboratory of Synthetic Biology and Biomanufacturing, Henan University, Kaifeng, China; Department of Environmental Management, Kaduna State University, Kaduna State, Nigeria
| | - Chunlei Yan
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China; Henan Key Laboratory of Synthetic Biology and Biomanufacturing, Henan University, Kaifeng, China
| | - Hui Chen
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China; Henan Key Laboratory of Synthetic Biology and Biomanufacturing, Henan University, Kaifeng, China.
| | - Qiang Wang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China; Henan Key Laboratory of Synthetic Biology and Biomanufacturing, Henan University, Kaifeng, China.
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2
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Wei N, Hu C, Dittmann E, Song L, Gan N. The biological functions of microcystins. WATER RESEARCH 2024; 262:122119. [PMID: 39059200 DOI: 10.1016/j.watres.2024.122119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 07/16/2024] [Accepted: 07/17/2024] [Indexed: 07/28/2024]
Abstract
Microcystins are potent hepatotoxins predominantly produced by bloom-forming freshwater cyanobacteria (e.g., Microcystis, Planktothrix, Dolichospermum). Microcystin biosynthesis involves large multienzyme complexes and tailoring enzymes encoded by the mcy gene cluster. Mutation, recombination, and deletion events have shaped the mcy gene cluster in the course of evolution, resulting in a large diversity of microcystin congeners and the natural coexistence of toxic and non-toxic strains. The biological functions of microcystins and their association with algal bloom formation have been extensively investigated over the past decades. This review synthesizes recent advances in decoding the biological role of microcystins in carbon/nitrogen metabolism, antioxidation, colony formation, and cell-to-cell communication. Microcystins appear to adopt multifunctional roles in cyanobacteria that reflect the adaptive plasticity of toxic cyanobacteria to changing environments.
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Affiliation(s)
- Nian Wei
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China
| | - Chenlin Hu
- College of Pharmacy, University of Houston, Houston, TX 77204, USA
| | - Elke Dittmann
- Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam-Golm, Germany
| | - Lirong Song
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Nanqin Gan
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
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Mugani R, El Khalloufi F, Redouane EM, Haida M, Aba RP, Essadki Y, El Amrani Zerrifi S, Hejjaj A, Ouazzani N, Campos A, Grossart HP, Mandi L, Vasconcelos V, Oudra B. Unlocking the potential of bacterioplankton-mediated microcystin degradation and removal: A bibliometric analysis of sustainable water treatment strategies. WATER RESEARCH 2024; 255:121497. [PMID: 38555787 DOI: 10.1016/j.watres.2024.121497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 01/31/2024] [Accepted: 03/19/2024] [Indexed: 04/02/2024]
Abstract
Microcystins (MCs) constitute a significant threat to human and environmental health, urging the development of effective removal methods for these toxins. In this review, we explore the potential of MC-degrading bacteria as a solution for the removal of MCs from water. The review insights into the mechanisms of action employed by these bacteria, elucidating their ability to degrade and thus remove MCs. After, the review points out the influence of the structural conformation of MCs on their removal, particularly their stability at different water depths within different water bodies. Then, we review the crucial role played by the production of MCs in ensuring the survival and safeguarding of the enzymatic activities of Microcystis cells. This justifies the need for developing effective and sustainable methods for removing MCs from aquatic ecosystems, given their critical ecological function and potential toxicity to humans and animals. Thereafter, challenges and limitations associated with using MC-degrading bacteria in water treatment are discussed, emphasizing the need for further research to optimize the selection of bacterial strains used for MCs biodegradation. The interaction of MCs-degrading bacteria with sediment particles is also crucial for their toxin removal potential and its efficiency. By presenting critical information, this review is a valuable resource for researchers, policymakers, and stakeholders involved in developing sustainable and practical approaches to remove MCs. Our review highlights the potential of various applications of MC-degrading bacteria, including multi-soil-layering (MSL) technologies. It emphasizes the need for ongoing research to optimize the utilization of MC-degrading bacteria in water treatment, ultimately ensuring the safety and quality of water sources. Moreover, this review highlights the value of bibliometric analyses in revealing research gaps and trends, providing detailed insights for further investigations. Specifically, we discuss the importance of employing advanced genomics, especially combining various OMICS approaches to identify and optimize the potential of MCs-degrading bacteria.
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Affiliation(s)
- Richard Mugani
- Water, Biodiversity and Climate Change Laboratory, Faculty of Sciences Semlalia, Cadi Ayyad University, Av. Prince My Abdellah, P.O. Box 2390, Marrakech 40000, Morocco; National Center for Studies and Research on Water and Energy, Cadi Ayyad University, P.O. Box: 511, 40000 Marrakech, Morocco; Department of Plankton and Microbial Ecology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Zur alten Fischerhuette 2, 14775 Stechlin, Germany
| | - Fatima El Khalloufi
- Natural Resources Engineering and Environmental Impacts Team, Multidisciplinary Research and Innovation Laboratory, Polydisciplinary Faculty of Khouribga, Sultan Moulay Slimane University of Beni Mellal, B.P.: 145, 25000, Khouribga, Morocco
| | - El Mahdi Redouane
- Water, Biodiversity and Climate Change Laboratory, Faculty of Sciences Semlalia, Cadi Ayyad University, Av. Prince My Abdellah, P.O. Box 2390, Marrakech 40000, Morocco
| | - Mohammed Haida
- Water, Biodiversity and Climate Change Laboratory, Faculty of Sciences Semlalia, Cadi Ayyad University, Av. Prince My Abdellah, P.O. Box 2390, Marrakech 40000, Morocco
| | - Roseline Prisca Aba
- Water, Biodiversity and Climate Change Laboratory, Faculty of Sciences Semlalia, Cadi Ayyad University, Av. Prince My Abdellah, P.O. Box 2390, Marrakech 40000, Morocco; National Center for Studies and Research on Water and Energy, Cadi Ayyad University, P.O. Box: 511, 40000 Marrakech, Morocco
| | - Yasser Essadki
- Water, Biodiversity and Climate Change Laboratory, Faculty of Sciences Semlalia, Cadi Ayyad University, Av. Prince My Abdellah, P.O. Box 2390, Marrakech 40000, Morocco
| | - Soukaina El Amrani Zerrifi
- Water, Biodiversity and Climate Change Laboratory, Faculty of Sciences Semlalia, Cadi Ayyad University, Av. Prince My Abdellah, P.O. Box 2390, Marrakech 40000, Morocco; Higher Institute of Nurses Professions and Health Techniques of Guelmim, Guelmim, Morocco
| | - Abdessamad Hejjaj
- National Center for Studies and Research on Water and Energy, Cadi Ayyad University, P.O. Box: 511, 40000 Marrakech, Morocco.
| | - Naaila Ouazzani
- Water, Biodiversity and Climate Change Laboratory, Faculty of Sciences Semlalia, Cadi Ayyad University, Av. Prince My Abdellah, P.O. Box 2390, Marrakech 40000, Morocco; National Center for Studies and Research on Water and Energy, Cadi Ayyad University, P.O. Box: 511, 40000 Marrakech, Morocco
| | - Alexandre Campos
- CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos, s/n, 4450-208 Porto, Portugal
| | - Hans-Peter Grossart
- Department of Plankton and Microbial Ecology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Zur alten Fischerhuette 2, 14775 Stechlin, Germany; Institute of Biochemistry and Biology, University of Potsdam, Maulbeeralle 2, 14469 Potsdam, Germany
| | - Laila Mandi
- Water, Biodiversity and Climate Change Laboratory, Faculty of Sciences Semlalia, Cadi Ayyad University, Av. Prince My Abdellah, P.O. Box 2390, Marrakech 40000, Morocco; National Center for Studies and Research on Water and Energy, Cadi Ayyad University, P.O. Box: 511, 40000 Marrakech, Morocco
| | - Vitor Vasconcelos
- CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos, s/n, 4450-208 Porto, Portugal; Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal.
| | - Brahim Oudra
- Water, Biodiversity and Climate Change Laboratory, Faculty of Sciences Semlalia, Cadi Ayyad University, Av. Prince My Abdellah, P.O. Box 2390, Marrakech 40000, Morocco
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Banerji A, Bagley MJ, Shoemaker JA, Tettenhorst DR, Nietch CT, Allen HJ, Santo Domingo JW. Evaluating putative ecological drivers of microcystin spatiotemporal dynamics using metabarcoding and environmental data. HARMFUL ALGAE 2019; 86:84-95. [PMID: 31358280 PMCID: PMC7877229 DOI: 10.1016/j.hal.2019.05.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 04/19/2019] [Accepted: 05/07/2019] [Indexed: 05/03/2023]
Abstract
Microcystin is a cyanobacterial hepatotoxin of global concern. Understanding the environmental factors that cause high concentrations of microcystin is crucial to the development of lake management strategies that minimize harmful exposures. While the literature is replete with studies linking cyanobacterial production of microcystin to changes in various nutrients, abiotic stressors, grazers, and competitors, no single biotic or abiotic factor has been shown to be reliably predictive of microcystin concentrations in complex ecosystems. We performed random forest regression analyses with 16S and 18S rRNA gene sequencing data and environmental data to determine which putative ecological drivers best explained spatiotemporal variation in total microcystin and several individual congeners in a eutrophic freshwater reservoir. Model performance was best for predicting concentrations of the congener MC-LR, with ca. 88% of spatiotemporal variance explained. Most of the variance was associated with changes in the relative abundance of the cyanobacterial genus Microcystis. Follow-up RF regression analyses revealed that factors that were the most important in predicting MC-LR were also the most important in predicting Microcystis population dynamics. We discuss how these results relate to prevailing ecological hypotheses regarding the function of microcystin.
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Affiliation(s)
- A Banerji
- US Environmental Protection Agency, Cincinnati, OH, 45268, USA
| | - M J Bagley
- US Environmental Protection Agency, Cincinnati, OH, 45268, USA
| | - J A Shoemaker
- US Environmental Protection Agency, Cincinnati, OH, 45268, USA
| | - D R Tettenhorst
- US Environmental Protection Agency, Cincinnati, OH, 45268, USA
| | - C T Nietch
- US Environmental Protection Agency, Cincinnati, OH, 45268, USA
| | - H J Allen
- US Environmental Protection Agency, Cincinnati, OH, 45268, USA
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5
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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: 10] [Impact Index Per Article: 1.7] [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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6
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Surup F, Viehrig K, Rachid S, Plaza A, Maurer CK, Hartmann RW, Müller R. Crocadepsins-Depsipeptides from the Myxobacterium Chondromyces crocatus Found by a Genome Mining Approach. ACS Chem Biol 2018; 13:267-272. [PMID: 29220569 DOI: 10.1021/acschembio.7b00900] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Analysis of the genome sequence of the myxobacterium Chondromyces crocatus Cm c5 revealed the presence of numerous cryptic megasynthetase gene clusters, one of which we here assign to two previously unknown chlorinated metabolites by a comparative gene inactivation and secondary metabolomics approach. Structure elucidation of these compounds revealed a unique cyclic depsipeptide skeleton featuring β- and δ-amide bonds of aspartic acid and 3-methyl ornithine moieties, respectively. Insights into their biosynthesis were obtained by targeted gene inactivation and feeding experiments employing isotope-labeled precursors. The compounds were produced ubiquitously by the species Chondromyces crocatus and were found to inhibit the carbon storage regulator-RNA interaction.
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Affiliation(s)
- Frank Surup
- Helmholtz Center
for Infection Research (HZI), Department Microbial Drugs, Inhoffenstraβe
7, 38124 Braunschweig, Germany
- German Centre for Infection Research Association (DZIF), partner site Hannover-Braunschweig, Inhoffenstraβe 7, 38124 Braunschweig, Germany
| | - Konrad Viehrig
- Helmholtz Institute for Pharmaceutical
Research Saarland (HIPS), Helmholtz Center for Infection Research
and Pharmaceutical Biotechnology, Saarland University, Campus, Building C2.3, 66123 Saarbrücken, Germany
| | - Shwan Rachid
- Helmholtz Institute for Pharmaceutical
Research Saarland (HIPS), Helmholtz Center for Infection Research
and Pharmaceutical Biotechnology, Saarland University, Campus, Building C2.3, 66123 Saarbrücken, Germany
| | - Alberto Plaza
- Helmholtz Institute for Pharmaceutical
Research Saarland (HIPS), Helmholtz Center for Infection Research
and Pharmaceutical Biotechnology, Saarland University, Campus, Building C2.3, 66123 Saarbrücken, Germany
| | - Christine K. Maurer
- Department of Drug Design & Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarland University, Campus E8.1, 66123 Saarbrücken, Germany
- German Centre for Infection Research Association (DZIF), partner site Hannover-Braunschweig, Inhoffenstraβe 7, 38124 Braunschweig, Germany
| | - Rolf W. Hartmann
- Department of Drug Design & Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarland University, Campus E8.1, 66123 Saarbrücken, Germany
- German Centre for Infection Research Association (DZIF), partner site Hannover-Braunschweig, Inhoffenstraβe 7, 38124 Braunschweig, Germany
| | - Rolf Müller
- Helmholtz Center
for Infection Research (HZI), Department Microbial Drugs, Inhoffenstraβe
7, 38124 Braunschweig, Germany
- Helmholtz Institute for Pharmaceutical
Research Saarland (HIPS), Helmholtz Center for Infection Research
and Pharmaceutical Biotechnology, Saarland University, Campus, Building C2.3, 66123 Saarbrücken, Germany
- German Centre for Infection Research Association (DZIF), partner site Hannover-Braunschweig, Inhoffenstraβe 7, 38124 Braunschweig, Germany
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Graça AP, Calisto R, Lage OM. Planctomycetes as Novel Source of Bioactive Molecules. Front Microbiol 2016; 7:1241. [PMID: 27570520 PMCID: PMC4982196 DOI: 10.3389/fmicb.2016.01241] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 07/26/2016] [Indexed: 11/13/2022] Open
Abstract
Marine environments are a fruitful source of bioactive compounds some of which are the newest leading drugs in medicinal therapeutics. Of particular importance are organisms like sponges and macroalgae and their associated microbiome. Planctomycetes, abundant in macroalgae biofilms, are promising producers of bioactive compounds since they share characteristics, like large genomes and complex life cycles, with the most bioactive bacteria, the Actinobacteria. Furthermore, genome mining revealed the presence of secondary metabolite pathway genes or clusters in 13 analyzed Planctomycetes genomes. In order to assess the antimicrobial production of a large and diverse collection of Planctomycetes isolated from macroalgae from the Portuguese coast, molecular, and bioactivity assays were performed in 40 bacteria from several taxa. Two genes commonly associated with the production of bioactive compounds, nonribosomal peptide synthetases (NRPS), and polyketide synthases (PKS) genes were screened. Molecular analysis revealed that 95% of the planctomycetes potentially have one or both secondary bioactive genes; 85% amplified with PKS-I primers and 55% with NRPS primers. Some of the amplified genes were confirmed to be involved in secondary metabolite pathways. Using bioinformatic tools their biosynthetic pathways were predicted. The secondary metabolite genomic potential of strains LF1, UC8, and FC18 was assessed using in silico analysis of their genomes. Aqueous and organic extracts of the Planctomycetes were evaluated for their antimicrobial activity against an environmental Escherichia coli, E. coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 6633, and a clinical isolate of Candida albicans. The screening assays showed a high number of planctomycetes with bioactive extracts revealing antifungal (43%) and antibacterial (54%) activity against C. albicans and B. subtilis, respectively. Bioactivity was observed in strains from Rhodopirellula lusitana, R. rubra, R. baltica, Roseimaritima ulvae, and Planctomyces brasiliensis. This study confirms the bioactive capacity of Planctomycetes to produce antimicrobial compounds and encourages further studies envisaging molecule isolation and characterization for the possible discovery of new drugs.
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Affiliation(s)
- Ana P Graça
- Departamento de Biologia, Faculdade de Ciências, Universidade do PortoPorto, Portugal; CIIMAR-Centro Interdisciplinar de Investigação Marinha e Ambiental-Universidade do PortoPorto, Portugal
| | - Rita Calisto
- Departamento de Biologia, Faculdade de Ciências, Universidade do PortoPorto, Portugal; CIIMAR-Centro Interdisciplinar de Investigação Marinha e Ambiental-Universidade do PortoPorto, Portugal
| | - Olga M Lage
- Departamento de Biologia, Faculdade de Ciências, Universidade do PortoPorto, Portugal; CIIMAR-Centro Interdisciplinar de Investigação Marinha e Ambiental-Universidade do PortoPorto, Portugal
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O'Neill EC, Trick M, Hill L, Rejzek M, Dusi RG, Hamilton CJ, Zimba PV, Henrissat B, Field RA. The transcriptome of Euglena gracilis reveals unexpected metabolic capabilities for carbohydrate and natural product biochemistry. MOLECULAR BIOSYSTEMS 2016; 11:2808-20. [PMID: 26289754 DOI: 10.1039/c5mb00319a] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Euglena gracilis is a highly complex alga belonging to the green plant line that shows characteristics of both plants and animals, while in evolutionary terms it is most closely related to the protozoan parasites Trypanosoma and Leishmania. This well-studied organism has long been known as a rich source of vitamins A, C and E, as well as amino acids that are essential for the human diet. Here we present de novo transcriptome sequencing and preliminary analysis, providing a basis for the molecular and functional genomics studies that will be required to direct metabolic engineering efforts aimed at enhancing the quality and quantity of high value products from E. gracilis. The transcriptome contains over 30,000 protein-encoding genes, supporting metabolic pathways for lipids, amino acids, carbohydrates and vitamins, along with capabilities for polyketide and non-ribosomal peptide biosynthesis. The metabolic and environmental robustness of Euglena is supported by a substantial capacity for responding to biotic and abiotic stress: it has the capacity to deploy three separate pathways for vitamin C (ascorbate) production, as well as producing vitamin E (α-tocopherol) and, in addition to glutathione, the redox-active thiols nor-trypanothione and ovothiol.
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Affiliation(s)
- Ellis C O'Neill
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.
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Nishizawa T, Neagari Y, Miura T, Asayama M, Murata K, Harada KI, Shirai M. Molecular Analysis of the Cyanobacterial Community in Gastric Contents of Egrets with Symptoms of Steatitis. Open Microbiol J 2015; 9:160-6. [PMID: 26668668 PMCID: PMC4676040 DOI: 10.2174/1874285801509010160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 05/03/2015] [Accepted: 08/01/2015] [Indexed: 11/22/2022] Open
Abstract
Many deaths of wild birds that have drunk water contaminated with hepatotoxic microcystin-producing cyanobacteria have been reported. A mass death of egrets and herons with steatitis were found at the agricultural reservoir occurring cyanobacterial waterblooms. This study aimed to verify a hypothesis that the egrets and herons which died in the reservoir drink microcystin-producing cyanobacteria and microcystin involves in the cause of death as well as the symptoms of steatitis. The cyanobacterial community in gastric contents of egrets and herons that died from steatitis was assessed using cyanobacterial 16S rRNA-based terminal-restriction fragment length polymorphism (T-RFLP) profiling and a cyanobacterial 16S rRNA-based clone library analysis. In addition, PCR amplification of the mcyB-C region and the mcyG gene, involved in microcystin biosynthesis, was examined. The cyanobacterial community in the gastric contents of two birds showed a simplistic composition. A comparison of cyanobacterial T-RFLP profiling and cloned sequences suggested that the genus Microcystis predominated in both samples of egrets died. Although we confirmed that two egrets which died in the reservoir have taken in cyanobacterial waterblooms containing the genus Microcystis, no mcy gene was detected in both samples according to the mcy gene-based PCR analysis. This study is the first to show the profiling and traceability of a cyanobacterial community in the gastric contents of wild birds by molecular analysis. Additionally, we consider causing symptoms of steatitis in the dead egrets.
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Affiliation(s)
| | - Yasuko Neagari
- Laboratory for Intellectual Fundamentals for Environmental Studies, National Institute for Environmental Studies, Ibaraki 305-8506, Japan
| | - Takamasa Miura
- College of Agriculture, Ibaraki University, Ibaraki 300-0393, Japan
| | - Munehiko Asayama
- College of Agriculture, Ibaraki University, Ibaraki 300-0393, Japan
| | - Koichi Murata
- College of Bioresource Sciences, Nihon University, Kanagawa 252-0880, Japan
| | - Ken-Ichi Harada
- Graduate School of Environmental and Human Science and Faculty of Pharmacy, Meijo University, Aichi 468-8503, Japan
| | - Makoto Shirai
- College of Agriculture, Ibaraki University, Ibaraki 300-0393, Japan
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Elucidation of insertion elements carried on plasmids and in vitro construction of shuttle vectors from the toxic cyanobacterium Planktothrix. Appl Environ Microbiol 2014; 80:4887-97. [PMID: 24907328 DOI: 10.1128/aem.01188-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Several gene clusters that are responsible for toxin synthesis in bloom-forming cyanobacteria have been found to be associated with transposable elements (TEs). In particular, insertion sequence (IS) elements were shown to play a role in the inactivation or recombination of the genes responsible for cyanotoxin synthesis. Plasmids have been considered important vectors of IS element distribution to the host. In this study, we aimed to elucidate the IS elements propagated on the plasmids and the chromosome of the toxic cyanobacterium Planktothrix agardhii NIVA-CYA126/8 by means of high-throughput sequencing. In total, five plasmids (pPA5.5, pPA14, pPA50, pPA79, and pPA115, of 5, 6, 50, 79, and 120 kbp, respectively) were elucidated, and two plasmids (pPA5.5, pPA115) were found to propagate full IS element copies. Large stretches of shared DNA information between plasmids were constituted of TEs. Two plasmids (pPA5.5, pPA14) were used as candidates to engineer shuttle vectors (named pPA5.5SV and pPA14SV, respectively) in vitro by PCR amplification and the subsequent transposition of the Tn5 cat transposon containing the R6Kγ origin of replication of Escherichia coli. While pPA5.5SV was found to be fully segregated, pPA14SV consistently co-occurred with its wild-type plasmid even under the highest selective pressure. Interestingly, the Tn5 cat transposon became transferred by homologous recombination into another plasmid, pPA50. The availability of shuttle vectors is considered to be of relevance in investigating genome plasticity as a consequence of homologous recombination events. Combining the potential of high-throughput sequencing and in vitro production of shuttle vectors makes it simple to produce species-specific shuttle vectors for many cultivable prokaryotes.
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11
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Dittmann E, Fewer DP, Neilan BA. Cyanobacterial toxins: biosynthetic routes and evolutionary roots. FEMS Microbiol Rev 2013; 37:23-43. [DOI: 10.1111/j.1574-6976.2012.12000.x] [Citation(s) in RCA: 239] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 08/22/2012] [Accepted: 08/24/2012] [Indexed: 11/27/2022] Open
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Fewer DP, Halinen K, Sipari H, Bernardová K, Mänttäri M, Eronen E, Sivonen K. Non-autonomous transposable elements associated with inactivation of microcystin gene clusters in strains of the genus Anabaena isolated from the Baltic Sea. ENVIRONMENTAL MICROBIOLOGY REPORTS 2011; 3:189-194. [PMID: 23761251 DOI: 10.1111/j.1758-2229.2010.00207.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Microcystins are potent peptide toxins produced by a range of distantly related cyanobacteria. They are assembled on a large enzyme complex encoded by the 55 kb microcystin synthetase (mcy) gene cluster. Here we report two strains of the genus Anabaena isolated from the Baltic Sea, which contain the entire mcy gene cluster but do not produce microcystins. Transcription analysis demonstrated that mcy genes were not expressed in these strains. We identified short insertion elements interrupting the mcyA, mcyD and mcyE genes in the two strains isolated in different years from different parts of the Baltic Sea. The 126-207 bp insertion elements encoded both terminal inverted repeats and direct repeats but lacked transposases. However, we found evidence for transposition of these elements despite the absence of genes encoding transposases, suggesting that they are non-autonomous mobile miniature inverted-repeat transposable elements (MITEs) recently described from cyanobacteria. The MITE insertion elements were present in mcyD genes amplified directly from the cyanobacterial community present in the Baltic Sea blooms from 2005. The results demonstrate that mcy gene cluster mutants can make up a stable proportion of the mcy gene pool in the Baltic Sea population.
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Affiliation(s)
- David P Fewer
- Department of Food and Environmental Sciences, University of Helsinki, Viikki Biocenter, PO Box 56, 00014 Helsinki, Finland
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Nishizawa T, Ueda A, Nakano T, Nishizawa A, Miura T, Asayama M, Fujii K, Harada KI, Shirai M. Characterization of the locus of genes encoding enzymes producing heptadepsipeptide micropeptin in the unicellular cyanobacterium Microcystis. J Biochem 2011; 149:475-85. [PMID: 21212071 DOI: 10.1093/jb/mvq150] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The gene cluster involved in producing the cyclic heptadepsipeptide micropeptin was cloned from the genome of the unicellular cyanobacterium Microcystis aeruginosa K-139. Sequencing revealed four genes encoding non-ribosomal peptide synthetases (NRPSs) that are highly similar to the gene cluster involved in cyanopeptolins biosynthesis. According to predictions based on the non-ribosomal consensus code, the order of the mcnABCE NPRS modules was well consistent with that of the biosynthetic assembly of cyclic peptides. The biochemical analysis of a McnB(K-139) adenylation domain and the knock-out of mcnC in a micropeptin-producing strain, M. viridis S-70, revealed that the mcn gene clusters were responsible for the production of heptadepsipeptide micropeptins. A detailed comparison of nucleotide sequences also showed that the regions between the mcnC and mcnE genes of M. aeruginosa K-139 retained short stretches of DNA homologous to halogenase genes involved in the synthesis of halogenated cyclic peptides of the cyanopeptolin class including anabaenopeptilides. This suggests that the mcn clusters of M. aeruginosa K-139 have lost the halogenase genes during evolution. Finally, a comparative bioinformatics analysis of the congenial gene cluster for depsipetide biosynthesis suggested the diversification and propagation of the NRPS genes in cyanobacteria.
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Affiliation(s)
- Tomoyasu Nishizawa
- Laboratory of Molecular Genetics, College of Agriculture, Ibaraki University, Ami, Ibaraki 300-0393, Japan.
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Sainis I, Fokas D, Vareli K, Tzakos AG, Kounnis V, Briasoulis E. Cyanobacterial cyclopeptides as lead compounds to novel targeted cancer drugs. Mar Drugs 2010; 8:629-57. [PMID: 20411119 PMCID: PMC2857373 DOI: 10.3390/md8030629] [Citation(s) in RCA: 42] [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: 01/04/2010] [Revised: 02/10/2010] [Accepted: 02/26/2010] [Indexed: 12/22/2022] Open
Abstract
Cyanobacterial cyclopeptides, including microcystins and nodularins, are considered a health hazard to humans due to the possible toxic effects of high consumption. From a pharmacological standpoint, microcystins are stable hydrophilic cyclic heptapeptides with a potential to cause cellular damage following uptake via organic anion-transporting polypeptides (OATP). Their intracellular biological effects involve inhibition of catalytic subunits of protein phosphatase 1 (PP1) and PP2, glutathione depletion and generation of reactive oxygen species (ROS). Interestingly, certain OATPs are prominently expressed in cancers as compared to normal tissues, qualifying MC as potential candidates for cancer drug development. In the era of targeted cancer therapy, cyanotoxins comprise a rich source of natural cytotoxic compounds with a potential to target cancers expressing specific uptake transporters. Moreover, their structure offers opportunities for combinatorial engineering to enhance the therapeutic index and resolve organ-specific toxicity issues. In this article, we revisit cyanobacterial cyclopeptides as potential novel targets for anticancer drugs by summarizing existing biomedical evidence, presenting structure-activity data and discussing developmental perspectives.
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Affiliation(s)
- Ioannis Sainis
- Human Cancer Biobank Center, University of Ioannina, Greece; E-Mails:
(I.S.);
(K.V.);
(A.T.)
| | - Demosthenes Fokas
- Department of Materials Science and Engineering, University of Ioannina, Greece; E-Mail:
(D.F.)
| | - Katerina Vareli
- Human Cancer Biobank Center, University of Ioannina, Greece; E-Mails:
(I.S.);
(K.V.);
(A.T.)
- Department of Biological Applications and Technologies, University of Ioannina, Greece
| | - Andreas G. Tzakos
- Human Cancer Biobank Center, University of Ioannina, Greece; E-Mails:
(I.S.);
(K.V.);
(A.T.)
- Department of Chemistry, University of Ioannina, Greece
| | | | - Evangelos Briasoulis
- Human Cancer Biobank Center, University of Ioannina, Greece; E-Mails:
(I.S.);
(K.V.);
(A.T.)
- School of Medicine, University of Ioannina, Greece; E-Mail:
(V.K.)
- * Author to whom correspondence should be addressed; E-Mail:
or
; Tel.: +30-265-100-7713; Fax: +30-265-100-8087
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Méjean A, Mann S, Vassiliadis G, Lombard B, Loew D, Ploux O. In Vitro Reconstitution of the First Steps of Anatoxin-a Biosynthesis in Oscillatoria PCC 6506: From Free l-Proline to Acyl Carrier Protein Bound Dehydroproline. Biochemistry 2009; 49:103-13. [DOI: 10.1021/bi9018785] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Annick Méjean
- Biochimie des micro-organismes, Laboratoire Charles Friedel, UMR CNRS 7223, ENSCP, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05, France
- Université Paris Diderot-Paris 7, 75013 Paris, France
| | - Stéphane Mann
- Biochimie des micro-organismes, Laboratoire Charles Friedel, UMR CNRS 7223, ENSCP, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05, France
| | - Gaëlle Vassiliadis
- Biochimie des micro-organismes, Laboratoire Charles Friedel, UMR CNRS 7223, ENSCP, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05, France
- Université Paris Diderot-Paris 7, 75013 Paris, France
| | - Bérangère Lombard
- Laboratory of Proteomic Mass Spectrometry, Centre de Recherche, Institut Curie, 26 rue d'Ulm, 75248 Paris, France
| | - Damarys Loew
- Laboratory of Proteomic Mass Spectrometry, Centre de Recherche, Institut Curie, 26 rue d'Ulm, 75248 Paris, France
| | - Olivier Ploux
- Biochimie des micro-organismes, Laboratoire Charles Friedel, UMR CNRS 7223, ENSCP, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05, France
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