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Chen Y, Jiang Y, He Z, Gao J, Li R, Yu G. First report of PST-producing Microseira wollei from China reveals its novel toxin profile. HARMFUL ALGAE 2024; 137:102655. [PMID: 39003021 DOI: 10.1016/j.hal.2024.102655] [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: 01/16/2024] [Revised: 04/26/2024] [Accepted: 05/21/2024] [Indexed: 07/15/2024]
Abstract
Microseira wollei, a globally distributed freshwater bloom-forming benthic cyanobacterium, is known for its production of cyanotoxins and taste and odor (T&O). While CYN (Cylindrospermopsin)-producing populations of M. wollei are confined to Australia, PST (Paralytic shellfish toxins)-producing populations have been exclusively documented in North America. In this study, four benthic cyanobacterial strains, isolated from West Lake in China, were identified as M. wollei based on morphological and phylogenetic analyses. Detection of sxtA gene and UPLC-MS/MS analysis conclusively confirmed the PST-producing capability of M. wollei CHAB5998. In the phylogenetic tree of 16S rDNA, M. wollei strains formed a monophyletic group with two subclades. Notably, non-PST-producing Chinese strains clustered with Australian strains in Clade II, while all other strains, including PST-producing ones, clustered in Clade I. Additionally, CHAB5998 contains ten PST variants, of which STX, NEO, GTX2, GTX3, GTX5 and C1 were identified for the first time in M. wollei. Sequence analysis of PST biosynthetic gene cluster (sxt) genes indicated potential base variations, gene rearrangements, insertions, and deletions in the strain CHAB5998. Also, sxt gene has a longer evolutionary history in M. wollei than that in cyanobacteria from Nostocales. Multiple recombination breakpoints detected in sxt genes and the inconsistency in the topology of the phylogenetic trees between sxt and 16S rDNA suggested that multiple horizontal gene transfers (HGT) have occurred. Overall, the present study marks the first documented occurrence of PST-producing M. wollei outside of North America and identifies it as the first toxic freshwater benthic cyanobacterium in China. This revelation implies that benthic cyanobacteria may pose a higher environmental risk in China than previously acknowledged.
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Affiliation(s)
- Youxin Chen
- CAS Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Yongguang Jiang
- Department of Biological Sciences and Technology, School of Environmental Studies, China University of Geosciences, Wuhan, 430074, China
| | - Zhongshi He
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, Baltimore, MD, 21202, USA
| | - Jin Gao
- CAS Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Renhui Li
- Zhejiang Provincial Key Laboratory for Subtropical Water Environment and Marine Biological Resources Protection, Wenzhou University, Wenzhou, 325035, China; National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Wenzhou, Zhejiang, 325035, China
| | - Gongliang Yu
- CAS Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.
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2
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Li H, Li R, Kang J, Hii KS, Mohamed HF, Xu X, Luo Z. Okeanomitos corallinicola gen. and sp. nov. (Nostocales, Cyanobacteria), a new toxic marine heterocyte-forming Cyanobacterium from a coral reef. JOURNAL OF PHYCOLOGY 2024; 60:908-927. [PMID: 38943258 DOI: 10.1111/jpy.13473] [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: 01/03/2024] [Revised: 05/05/2024] [Accepted: 05/11/2024] [Indexed: 07/01/2024]
Abstract
Cyanobacterial mats supplanting coral and spreading coral diseases in tropical reefs, intensified by environmental shifts caused by human-induced pressures, nutrient enrichment, and global climate change, pose grave risks to the survival of coral ecosystems. In this study, we characterized Okeanomitos corallinicola gen. and sp. nov., a newly discovered toxic marine heterocyte-forming cyanobacterium isolated from a coral reef ecosystem of the South China Sea. Phylogenetic analysis, based on the 16S rRNA gene and the secondary structure of the 16S-23S rRNA intergenic region, placed this species in a clade distinct from closely related genera, that is, Sphaerospermopsis stricto sensu, Raphidiopsis, and Amphiheterocytum. The O. corallinicola is a marine benthic species lacking gas vesicles, distinguishing it from other members of the Aphanizomenonaceae family. The genome of O. corallinicola is large and exhibits diverse functional capabilities, potentially contributing to the resilience and adaptability of coral reef ecosystems. In vitro assays revealed that O. corallinicola demonstrates notable cytotoxic activity against various cancer cell lines, suggesting its potential as a source of novel anticancer compounds. Furthermore, the identification of residual saxitoxin biosynthesis function in the genome of O. corallinicola, a marine cyanobacteria, supports the theory that saxitoxin genes in cyanobacteria and dinoflagellates may have been horizontally transferred between them or may have originated from a shared ancestor. Overall, the identification and characterization of O. corallinicola provides valuable contributions to cyanobacterial taxonomy, offering novel perspectives on complex interactions within coral reef ecosystems.
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Affiliation(s)
- Haiyan Li
- Key Laboratory of Marine Ecological Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China
- Institute of Marine Drugs/Guangxi Key Laboratory of Marine Drugs, Guangxi University of Chinese Medicine, Nanning, China
| | - Renhui Li
- College of Life and Environmental Sciences, Wenzhou University, Wenzhou, China
| | - Jianhua Kang
- Key Laboratory of Marine Ecological Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China
| | - Kieng Soon Hii
- Bachok Marine Research Station, Institute of Ocean and Earth Sciences, University of Malaya, Bachok, Kelantan, Malaysia
| | - Hala F Mohamed
- Botany & Microbiology Department, Faculty of Science, Al-Azhar University (Girls Branch), Cairo, Egypt
| | - Xinya Xu
- Institute of Marine Drugs/Guangxi Key Laboratory of Marine Drugs, Guangxi University of Chinese Medicine, Nanning, China
| | - Zhaohe Luo
- Key Laboratory of Marine Ecological Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China
- Observation and Research Station of Coastal Wetland Ecosystem in Beibu Gulf, Ministry of Natural Resources, Beihai, China
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Hu W, Su S, Mohamed HF, Xiao J, Kang J, Krock B, Xie B, Luo Z, Chen B. Assessing the global distribution and risk of harmful microalgae: A focus on three toxic Alexandrium dinoflagellates. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 948:174767. [PMID: 39004369 DOI: 10.1016/j.scitotenv.2024.174767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Revised: 06/18/2024] [Accepted: 07/11/2024] [Indexed: 07/16/2024]
Abstract
Harmful dinoflagellates and their resulting blooms pose a threat to marine life and human health. However, to date, global maps of marine life often overlook harmful microorganisms. As harmful algal blooms (HABs) increase in frequency, severity, and extent, understanding the distribution of harmful dinoflagellates and their drivers is crucial for their management. We used MaxEnt, random forest, and ensemble models to map the habitats of the representative HABs species in the genus Alexandrium, including A. catenella, A. minutum, and A. pacificum. Since species occurrence records used in previous studies were solely morphology-based, potentially leading to misidentifications, we corrected these species' distribution records using molecular criteria. The results showed that the key environmental drivers included the distance to the coastline, bathymetry, sea surface temperature (SST), and dissolved oxygen. Alexandrium catenella thrives in temperate to cold zones and is driven by low SST and high oxygen levels. Alexandrium pacificum mainly inhabits the Temperate Northern Pacific and prefers warmer SST and lower oxygen levels. Alexandrium minutum thrives universally and adapts widely to SST and oxygen. By analyzing the habitat suitability of locations with recorded HAB occurrences, we found that high habitat suitability could serve as a reference indicator for bloom risk. Therefore, we have proposed a qualitative method to spatially assess the harmful algae risk according to the habitat suitability. On the global risk map, coastal temperate seas, such as the Mediterranean, Northwest Pacific, and Southern Australia, faced higher risks. Although HABs currently have restricted geographic distributions, our study found these harmful algae possess high environmental tolerance and can thrive across diverse habitats. HAB impacts could increase if climate changes or ocean conditions became more favorable. Marine transportation may also spread the harmful algae to new unaffected ecosystems. This study has pioneered the assessment of harmful algal risk based on habitat suitability.
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Affiliation(s)
- Wenjia Hu
- Key Laboratory of Marine Ecological Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
| | - Shangke Su
- Key Laboratory of Marine Ecological Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
| | - Hala F Mohamed
- Botany & Microbiology Department, Faculty of Science, Al-Azhar University (Girls Branch), Cairo 11751, Egypt
| | - Jiamei Xiao
- College of Ocean and Earth Sciences, Xiamen University, Xiamen 361005, China
| | - Jianhua Kang
- Key Laboratory of Marine Ecological Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
| | - Bernd Krock
- Helmholtz Center for Polar and Marine Research, Alfred Wegener Institute, Am Handelshafen 12, D-27570 Bremerhaven, Germany
| | - Bin Xie
- Key Laboratory of Marine Ecological Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China
| | - Zhaohe Luo
- Key Laboratory of Marine Ecological Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China.
| | - Bin Chen
- Key Laboratory of Marine Ecological Conservation and Restoration, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China.
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Li J, Wang J, He X, Gu H, Xu X, Liang C, Wang Y, Xu X, Jia L, Chen J, Jiang M, Chen J. The ciliate Euplotes balteatus is resistant to Paralytic Shellfish Toxins from Alexandrium minutum (Dinophyceae). WATER RESEARCH X 2024; 23:100229. [PMID: 39099803 PMCID: PMC11294722 DOI: 10.1016/j.wroa.2024.100229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2024] [Revised: 05/30/2024] [Accepted: 06/08/2024] [Indexed: 08/06/2024]
Abstract
Research on interactions between grazers and toxigenic algae is fundamental for understanding toxin dynamics within aquatic ecosystems and developing biotic approaches to mitigate harmful algal blooms. The dinoflagellate Alexandrium minutum is a well-known microalga responsible for paralytic shellfish toxins (PSTs) contamination in many coastal regions worldwide. This study investigated the impact of the ciliate Euplotes balteatus on cell density and PSTs transfer in simulated A. minutum blooms under controlled conditions. E. balteatus exhibited resistance to the PSTs produced by A. minutum with a density of up to 10,000 cells/mL, sustaining growth and reproduction while eliminating algal cells within a few days. The cellular PSTs content of A. minutum increased in response to the grazing pressure from E. balteatus. However, due to the substantial reduction in density, the overall toxicity of the algal population decreased to a negligible level. Most PSTs contained within algal cells were temporarily accumulated in E. balteatus before being released into the water column, suggesting unclear mechanisms for PSTs excretion in unicellular grazers. In principle, the grazing of E. balteatus on A. minutum promotes the transfer of the majority of intracellular PSTs into extracellular portions, thereby mitigating the risk of their accumulation and contamination through marine trophic pathways. However, this process also introduces an increase in the potential environmental hazards posed by extracellular PSTs to some extent.
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Affiliation(s)
- Jing Li
- Fujian Key Laboratory on Conservation and Sustainable Utilization of Marine Biodiversity, Fuzhou Institute of Oceanography, College of Geography and Oceanography, Minjiang University, Fuzhou, 350108, China
| | - Jinrong Wang
- The Second Geological Institute, China Metallurgical Geology Bureau, Fuzhou, 350108, China
| | - Xiuping He
- Key Laboratory for Marine Bioactive Substances and Modern Analytical Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266071, China
| | - Haifeng Gu
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, China
| | - Xin Xu
- Fujian Key Laboratory on Conservation and Sustainable Utilization of Marine Biodiversity, Fuzhou Institute of Oceanography, College of Geography and Oceanography, Minjiang University, Fuzhou, 350108, China
| | - Chen Liang
- Fujian Key Laboratory on Conservation and Sustainable Utilization of Marine Biodiversity, Fuzhou Institute of Oceanography, College of Geography and Oceanography, Minjiang University, Fuzhou, 350108, China
- Technology Innovation Center for Monitoring and Restoration Engineering of Ecological Fragile Zone in Southeast China, Ministry of Natural Resources, Fuzhou, 350001, China
| | - Yongchao Wang
- The Second Geological Institute, China Metallurgical Geology Bureau, Fuzhou, 350108, China
| | - Xiao Xu
- Fujian Key Laboratory on Conservation and Sustainable Utilization of Marine Biodiversity, Fuzhou Institute of Oceanography, College of Geography and Oceanography, Minjiang University, Fuzhou, 350108, China
| | - Linxuan Jia
- Fujian Key Laboratory on Conservation and Sustainable Utilization of Marine Biodiversity, Fuzhou Institute of Oceanography, College of Geography and Oceanography, Minjiang University, Fuzhou, 350108, China
| | - Junhui Chen
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, China
| | - Miaohua Jiang
- Fujian Key Laboratory on Conservation and Sustainable Utilization of Marine Biodiversity, Fuzhou Institute of Oceanography, College of Geography and Oceanography, Minjiang University, Fuzhou, 350108, China
| | - Jianming Chen
- Fujian Key Laboratory on Conservation and Sustainable Utilization of Marine Biodiversity, Fuzhou Institute of Oceanography, College of Geography and Oceanography, Minjiang University, Fuzhou, 350108, China
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5
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Bui QTN, Pradhan B, Kim HS, Ki JS. Environmental Factors Modulate Saxitoxins (STXs) Production in Toxic Dinoflagellate Alexandrium: An Updated Review of STXs and Synthesis Gene Aspects. Toxins (Basel) 2024; 16:210. [PMID: 38787062 PMCID: PMC11125744 DOI: 10.3390/toxins16050210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 04/23/2024] [Accepted: 04/28/2024] [Indexed: 05/25/2024] Open
Abstract
The marine dinoflagellate Alexandrium is known to form harmful algal blooms (HABs) and produces saxitoxin (STX) and its derivatives (STXs) that cause paralytic shellfish poisoning (PSP) in humans. Cell growth and cellular metabolism are affected by environmental conditions, including nutrients, temperature, light, and the salinity of aquatic systems. Abiotic factors not only engage in photosynthesis, but also modulate the production of toxic secondary metabolites, such as STXs, in dinoflagellates. STXs production is influenced by a variety of abiotic factors; however, the relationship between the regulation of these abiotic variables and STXs accumulation seems not to be consistent, and sometimes it is controversial. Few studies have suggested that abiotic factors may influence toxicity and STXs-biosynthesis gene (sxt) regulation in toxic Alexandrium, particularly in A. catenella, A. minutum, and A. pacificum. Hence, in this review, we focused on STXs production in toxic Alexandrium with respect to the major abiotic factors, such as temperature, salinity, nutrients, and light intensity. This review informs future research on more sxt genes involved in STXs production in relation to the abiotic factors in toxic dinoflagellates.
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Affiliation(s)
- Quynh Thi Nhu Bui
- Department of Life Science, Sangmyung University, Seoul 03016, Republic of Korea; (Q.T.N.B.); (H.-S.K.)
| | - Biswajita Pradhan
- Department of Biotechnology, Sangmyung University, Seoul 03016, Republic of Korea;
- Department of Botany, Model Degree College, Rayagada 765017, Odisha, India
| | - Han-Sol Kim
- Department of Life Science, Sangmyung University, Seoul 03016, Republic of Korea; (Q.T.N.B.); (H.-S.K.)
| | - Jang-Seu Ki
- Department of Life Science, Sangmyung University, Seoul 03016, Republic of Korea; (Q.T.N.B.); (H.-S.K.)
- Department of Biotechnology, Sangmyung University, Seoul 03016, Republic of Korea;
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6
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Bui QTN, Kim HS, Ki JS. Polyphyletic origin of saxitoxin biosynthesis genes in the marine dinoflagellate Alexandrium revealed by comparative transcriptomics. HARMFUL ALGAE 2024; 134:102620. [PMID: 38705616 DOI: 10.1016/j.hal.2024.102620] [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: 09/20/2023] [Revised: 02/26/2024] [Accepted: 03/15/2024] [Indexed: 05/07/2024]
Abstract
The marine dinoflagellate Alexandrium is known to form harmful algal blooms, and at least 14 species within the genus can produce saxitoxins (STXs). STX biosynthesis genes (sxt) are individually revealed in toxic dinoflagellates; however, the evolutionary history remains controversial. Herein, we determined the transcriptome sequences of toxic Alexandrium (A. catenella and A. pacificum) and non-toxic Alexandrium (A. fraterculus and A. fragae) and characterized their sxt by focusing on evolutionary events and STX production. Comparative transcriptome analysis revealed higher homology of the sxt in toxic Alexandrium than in non-toxic species. Notably, non-toxic Alexandrium spp. were found to have lost two sxt core genes, namely sxtA4 and sxtG. Expression levels of 28 transcripts related to eight sxt core genes showed that sxtA, sxtG, and sxtI were relatively high (>1.5) in the toxic group compared to the non-toxic group. In contrast, the non-toxic group showed high expression levels in sxtU (1.9) and sxtD (1.7). Phylogenetic tree comparisons revealed distinct evolutionary patterns between 28S rDNA and sxtA, sxtB, sxtI, sxtD, and sxtU. However, similar topology was observed between 28S rDNA, sxtS, and sxtH/T. In the sxtB and sxtI phylogeny trees, toxic Alexandrium and cyanobacteria were clustered together, separating from non-toxic species. These suggest that Alexandrium may acquire sxt genes independently via horizontal gene transfer from toxic cyanobacteria and other multiple sources, demonstrating monocistronic transcripts of sxt in dinoflagellates.
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Affiliation(s)
- Quynh Thi Nhu Bui
- Department of Life Science, Sangmyung University, Seoul 03016, South Korea
| | - Han-Sol Kim
- Department of Life Science, Sangmyung University, Seoul 03016, South Korea
| | - Jang-Seu Ki
- Department of Life Science, Sangmyung University, Seoul 03016, South Korea.
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Yu Z, Wang Z, Liu L. Electrophysiological techniques in marine microalgae study: A new perspective for harmful algal bloom (HAB) research. HARMFUL ALGAE 2024; 134:102629. [PMID: 38705615 DOI: 10.1016/j.hal.2024.102629] [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: 01/07/2024] [Revised: 04/11/2024] [Accepted: 04/15/2024] [Indexed: 05/07/2024]
Abstract
Electrophysiological techniques, by measuring bioelectrical signals and ion channel activities in tissues and cells, are now widely utilized to study ion channel-related physiological functions and their underlying mechanisms. Electrophysiological techniques have been extensively employed in the investigation of animals, plants, and microorganisms; however, their application in marine algae lags behind that in other organisms. In this paper, we present an overview of current electrophysiological techniques applicable to algae while reviewing the historical usage of such techniques in this field. Furthermore, we explore the potential specific applications of electrophysiological technology in harmful algal bloom (HAB) research. The application prospects in the studies of stress tolerance, competitive advantage, nutrient absorption, toxin synthesis and secretion by HAB microalgae are discussed and anticipated herein with the aim of providing novel perspectives on HAB investigations.
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Affiliation(s)
- Zhiming Yu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Laboratory of Marine Ecology and Environmental Science, Laoshan Laboratory, Qingdao, 266237, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China.
| | - Zhongshi Wang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Laboratory of Marine Ecology and Environmental Science, Laoshan Laboratory, Qingdao, 266237, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Lidong Liu
- The Djavad Mowafaghian Centre for Brian Health and Department of Medicine, University of British Columbia, Vancouver, BC, Canada
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Odehnalová K, Přibilová P, Maršálek B, Babica P. A fast and reliable LC-MS-MS method for the quantification of saxitoxin in blood plasma samples. J Anal Toxicol 2024; 48:119-125. [PMID: 38175940 DOI: 10.1093/jat/bkad092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 12/09/2023] [Accepted: 01/03/2024] [Indexed: 01/06/2024] Open
Abstract
Saxitoxins (STXs) are potent neurotoxins produced by marine dinoflagellates or freshwater cyanobacteria known to cause acute and eventually fatal human intoxications, which are classified as paralytic shellfish poisonings (PSPs). Rapid analysis of STXs in blood plasma can be used for a timely diagnosis and confirmation of PSPs. We developed a fast and simple method of STX extraction based on plasma sample acidification and precipitation by acetonitrile, followed by quantification using liquid chromatography-tandem mass spectrometry (LC-MS-MS). Our approach provides the results ≤30 min, with a limit of detection of 2.8 ng/mL and a lower limit of quantification of 5.0 ng/mL. Within-run and between-run precision experiments showed good reproducibility with ≤15% values. Standard curves for calibration were linear with correlation coefficients ≥0.98 across the assay calibration range (5-200 ng/mL). In an interlaboratory analytical exercise, the method was found to be 100% accurate in determining the presence or absence of STX in human plasma specimens, with recovery values of 86-99%. This simple method for STX determination in animal or human plasma can quickly and reliably diagnose STX exposures and confirm suspected PSP cases to facilitate patient treatment or expedite necessary public health or security actions.
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Affiliation(s)
- Klára Odehnalová
- Department of Experimental Phycology and Ecotoxicology, Institute of Botany, Czech Academy of Sciences, Lidická 25/27, Brno 60200, Czech Republic
| | - Petra Přibilová
- Department of Experimental Phycology and Ecotoxicology, Institute of Botany, Czech Academy of Sciences, Lidická 25/27, Brno 60200, Czech Republic
| | - Blahoslav Maršálek
- Department of Experimental Phycology and Ecotoxicology, Institute of Botany, Czech Academy of Sciences, Lidická 25/27, Brno 60200, Czech Republic
| | - Pavel Babica
- Department of Experimental Phycology and Ecotoxicology, Institute of Botany, Czech Academy of Sciences, Lidická 25/27, Brno 60200, Czech Republic
- RECETOX, Faculty of Science, Masaryk University, Kotlářská 2, Brno 61137, Czech Republic
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Huang D, Cheng CQ, Qiu JB, Huang Y, Zhang HY, Xu ZH, Wu SW, Huang YT, Chen J, Zou LG, Yang WD, Zheng XF, Li HY, Li DW. Mechanistic insights into the effects of diuron exposure on Alexandrium pacificum. WATER RESEARCH 2024; 250:120987. [PMID: 38113594 DOI: 10.1016/j.watres.2023.120987] [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: 09/20/2023] [Revised: 12/03/2023] [Accepted: 12/06/2023] [Indexed: 12/21/2023]
Abstract
Diuron (N-(3,4-dichlorophenyl)-N,N‑dimethylurea, DCMU), a ureic herbicide, is extensively used in agriculture to boost crop productivity; however, its extensive application culminates in notable environmental pollution, especially in aquatic habitats. Therefore, the present study investigated the effect of diuron on the dinoflagellate Alexandrium pacificum, which is known to induce harmful algal blooms (HAB), and its potential to biodegrade DCMU. Following a four-day DCMU exposure, our results revealed that A. pacificum proficiently assimilated DCMU at concentrations of 0.05 mg/L and 0.1 mg/L in seawater, attaining a complete reduction (100 % efficiency) after 96 h for both concentrations. Moreover, evaluations of paralytic shellfish toxins content indicated that cells subjected to higher DCMU concentrations (0.1 mg/L) exhibited reductions of 73.4 %, 86.7 %, and 75 % in GTX1, GTX4, and NEO, respectively. Exposure to DCMU led to a notable decrease in A. pacificum's photosynthetic efficacy, accompanied by increased levels of reactive oxygen species (ROS) and suppressed cell growth, with a growth inhibition rate of 41.1 % at 72 h. Proteomic investigations pinpointed the diminished expression levels of specific proteins like SxtV and SxtW, linked to paralytic shellfish toxins (PSTs) synthesis, as well as key proteins associated with Photosystem II, namely PsbA, PsbD, PsbO, and PsbU. Conversely, proteins central to the cysteine biosynthesis pathways exhibited enhanced expression. In summary, our results preliminarily resolved the molecular mechanisms underlying the response of A. pacificum to DCMU and revealed that DCMU affected the synthesis of PSTs. Meanwhile, our data suggested that A. pacificum has great potential in scavenging DCMU.
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Affiliation(s)
- Dan Huang
- Department of Sports Medicine, The First Affiliated Hospital, Guangdong Provincial Key Laboratory of Speed Capability, The Guangzhou Key Laboratory of Precision Orthopedics and Regenerative Medicine, Jinan University, Guangzhou 510630, China
| | - Cai-Qin Cheng
- Department of Sports Medicine, The First Affiliated Hospital, Guangdong Provincial Key Laboratory of Speed Capability, The Guangzhou Key Laboratory of Precision Orthopedics and Regenerative Medicine, Jinan University, Guangzhou 510630, China
| | - Jiang-Bing Qiu
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Yun Huang
- Department of Sports Medicine, The First Affiliated Hospital, Guangdong Provincial Key Laboratory of Speed Capability, The Guangzhou Key Laboratory of Precision Orthopedics and Regenerative Medicine, Jinan University, Guangzhou 510630, China
| | - Hao-Yun Zhang
- Department of Sports Medicine, The First Affiliated Hospital, Guangdong Provincial Key Laboratory of Speed Capability, The Guangzhou Key Laboratory of Precision Orthopedics and Regenerative Medicine, Jinan University, Guangzhou 510630, China
| | - Zhen-Hao Xu
- Department of Sports Medicine, The First Affiliated Hospital, Guangdong Provincial Key Laboratory of Speed Capability, The Guangzhou Key Laboratory of Precision Orthopedics and Regenerative Medicine, Jinan University, Guangzhou 510630, China
| | - Si-Wei Wu
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Yi-Tong Huang
- Department of Sports Medicine, The First Affiliated Hospital, Guangdong Provincial Key Laboratory of Speed Capability, The Guangzhou Key Laboratory of Precision Orthopedics and Regenerative Medicine, Jinan University, Guangzhou 510630, China
| | - Jian Chen
- State Key Laboratory of Medical Vector Surveillance, Zhuhai International Travel Healthcare Center, Zhuhai, Guangdong 519020, China
| | - Li-Gong Zou
- Department of Sports Medicine, The First Affiliated Hospital, Guangdong Provincial Key Laboratory of Speed Capability, The Guangzhou Key Laboratory of Precision Orthopedics and Regenerative Medicine, Jinan University, Guangzhou 510630, China
| | - Wei-Dong Yang
- Department of Sports Medicine, The First Affiliated Hospital, Guangdong Provincial Key Laboratory of Speed Capability, The Guangzhou Key Laboratory of Precision Orthopedics and Regenerative Medicine, Jinan University, Guangzhou 510630, China
| | - Xiao-Fei Zheng
- Department of Sports Medicine, The First Affiliated Hospital, Guangdong Provincial Key Laboratory of Speed Capability, The Guangzhou Key Laboratory of Precision Orthopedics and Regenerative Medicine, Jinan University, Guangzhou 510630, China
| | - Hong-Ye Li
- Department of Sports Medicine, The First Affiliated Hospital, Guangdong Provincial Key Laboratory of Speed Capability, The Guangzhou Key Laboratory of Precision Orthopedics and Regenerative Medicine, Jinan University, Guangzhou 510630, China
| | - Da-Wei Li
- Department of Sports Medicine, The First Affiliated Hospital, Guangdong Provincial Key Laboratory of Speed Capability, The Guangzhou Key Laboratory of Precision Orthopedics and Regenerative Medicine, Jinan University, Guangzhou 510630, China.
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10
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Zheng G, Xu X, Wu H, Fan L, Wang Q, Peng J, Guo M, Yang D, Tan Z. Contamination Status and Risk Assessment of Paralytic Shellfish Toxins in Shellfish along the Coastal Areas of China. Mar Drugs 2024; 22:64. [PMID: 38393035 PMCID: PMC10890588 DOI: 10.3390/md22020064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 01/19/2024] [Accepted: 01/24/2024] [Indexed: 02/25/2024] Open
Abstract
Paralytic shellfish toxins (PSTs) are widely distributed in shellfish along the coast of China, causing a serious threat to consumer health; however, there is still a lack of large-scale systematic investigations and risk assessments. Herein, 641 shellfish samples were collected from March to November 2020, and the PSTs' toxicity was detected via liquid chromatography-tandem mass spectrometry. Furthermore, the contamination status and potential dietary risks of PSTs were discussed. PSTs were detected in 241 shellfish samples with a detection rate of 37.60%. The average PST toxicities in mussels and ark shells were considerably higher than those in other shellfish. The PSTs mainly included N-sulfonylcarbamoyl toxins (class C) and carbamoyl toxins (class GTX), and the highest PST toxicity was 546.09 μg STX eq. kg-1. The PST toxicity in spring was significantly higher than those in summer and autumn (p < 0.05). Hebei Province had the highest average PST toxicity in spring. An acute exposure assessment showed that consumers in Hebei Province had a higher dietary risk, with mussels posing a significantly higher dietary risk to consumers. This research provides reference for the green and sustainable development of the shellfish industry and the establishment of a shellfish toxin prevention and control system.
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Affiliation(s)
- Guanchao Zheng
- Key Laboratory of Testing and Evaluation for Aquatic Product Safety and Quality, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; (G.Z.); (X.X.); (L.F.)
| | - Xizhen Xu
- Key Laboratory of Testing and Evaluation for Aquatic Product Safety and Quality, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; (G.Z.); (X.X.); (L.F.)
- Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Haiyan Wu
- Key Laboratory of Testing and Evaluation for Aquatic Product Safety and Quality, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; (G.Z.); (X.X.); (L.F.)
| | - Liqiang Fan
- Key Laboratory of Testing and Evaluation for Aquatic Product Safety and Quality, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; (G.Z.); (X.X.); (L.F.)
| | - Qianrui Wang
- China National Center for Food Safety Risk Assessment, Beijing 100000, China; (Q.W.); (D.Y.)
| | - Jixing Peng
- Key Laboratory of Testing and Evaluation for Aquatic Product Safety and Quality, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; (G.Z.); (X.X.); (L.F.)
| | - Mengmeng Guo
- Key Laboratory of Testing and Evaluation for Aquatic Product Safety and Quality, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; (G.Z.); (X.X.); (L.F.)
| | - Dajin Yang
- China National Center for Food Safety Risk Assessment, Beijing 100000, China; (Q.W.); (D.Y.)
| | - Zhijun Tan
- Key Laboratory of Testing and Evaluation for Aquatic Product Safety and Quality, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; (G.Z.); (X.X.); (L.F.)
- State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China
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11
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Flores-Holguín N, Salas-Leiva JS, Núñez-Vázquez EJ, Tovar-Ramírez D, Glossman-Mitnik D. Marine Toxins as Pharmaceutical Treasure Troves: A Focus on Saxitoxin Derivatives from a Computational Point of View. Molecules 2024; 29:275. [PMID: 38202857 PMCID: PMC10780485 DOI: 10.3390/molecules29010275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 12/30/2023] [Accepted: 12/31/2023] [Indexed: 01/12/2024] Open
Abstract
This work highlights the significant potential of marine toxins, particularly saxitoxin (STX) and its derivatives, in the exploration of novel pharmaceuticals. These toxins, produced by aquatic microorganisms and collected by bivalve mollusks and other filter-feeding organisms, offer a vast reservoir of chemical and biological diversity. They interact with sodium channels in physiological processes, affecting various functions in organisms. Exposure to these toxins can lead to symptoms ranging from tingling sensations to respiratory failure and cardiovascular shock, with STX being one of the most potent. The structural diversity of STX derivatives, categorized into carbamate, N-sulfocarbamoyl, decarbamoyl, and deoxydecarbamoyl toxins, offers potential for drug development. The research described in this work aimed to computationally characterize 18 STX derivatives, exploring their reactivity properties within marine sponges using conceptual density functional theory (CDFT) techniques. Additionally, their pharmacokinetic properties, bioavailability, and drug-likeness scores were assessed. The outcomes of this research were the chemical reactivity parameters calculated via CDFT as well as the estimated pharmacokinetic and ADME properties derived using computational tools. While they may not align directly, the integration of these distinct datasets enriches our comprehensive understanding of the compound's properties and potential applications. Thus, this study holds promise for uncovering new pharmaceutical candidates from the considered marine toxins.
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Affiliation(s)
- Norma Flores-Holguín
- Centro de Investigación en Materiales Avanzados, Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua 31136, Chih, Mexico; (J.S.S.-L.); (D.G.-M.)
| | - Joan S. Salas-Leiva
- Centro de Investigación en Materiales Avanzados, Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua 31136, Chih, Mexico; (J.S.S.-L.); (D.G.-M.)
| | - Erick J. Núñez-Vázquez
- Centro de Investigaciones Biológicas del Noroeste, Av. Instituto Politécnico Nacional 195, Col. Playa Palo de Santa Rita Sur, La Paz 23096, BCS, Mexico; (E.J.N.-V.); (D.T.-R.)
| | - Dariel Tovar-Ramírez
- Centro de Investigaciones Biológicas del Noroeste, Av. Instituto Politécnico Nacional 195, Col. Playa Palo de Santa Rita Sur, La Paz 23096, BCS, Mexico; (E.J.N.-V.); (D.T.-R.)
| | - Daniel Glossman-Mitnik
- Centro de Investigación en Materiales Avanzados, Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua 31136, Chih, Mexico; (J.S.S.-L.); (D.G.-M.)
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12
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Pichardo-Velarde JG, Estrada N, Alonso-Rodríguez R, Ascencio F. Growth and paralytic shellfish poisoning toxin production by a Mexican dinoflagellate strain of Alexandrium tamiyavanichii Balech (1994) under different nutrient conditions. MARINE POLLUTION BULLETIN 2024; 198:115802. [PMID: 37995589 DOI: 10.1016/j.marpolbul.2023.115802] [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: 05/04/2023] [Revised: 10/31/2023] [Accepted: 11/14/2023] [Indexed: 11/25/2023]
Abstract
Alexandrium tamiyavanichii is a marine dinoflagellate known to produce Paralytic Shellfish Poisoning (PSP) toxin. Thus, a strain was isolated from La Paz Bay, Baja California Sur, Mexico and used to explore whether stress conditions, such as phosphorus limitation (PL) and nitrogen enrichment (NE) modulate population growth and PSP toxin production in the GSe medium. Growth kinetics showed that the PL treatment produced a 3.4-fold increase in cell density versus control at day 30 of the culture cycle. The highest PSP concentration was found in the control culture (309 fmol cell-1) on day 21. Saxitoxin (STX) was the main analog in all the treatments (> 40 % mol). In conclusion, PL and NE treatments promoted growth kinetics in the species studied but did not affect the PSP toxin production. For the first time, the present research describes A. tamiyavanichii high toxicity strain isolated from Mexican coasts relative to the South-Atlantic strains.
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Affiliation(s)
- Jorge-Gerardo Pichardo-Velarde
- Centro de Investigaciones Biológicas del Noroeste, S.C. (CIBNOR), Av. I.P.N. 195, Col. Playa Palo de Santa Rita Sur, La Paz, Baja California Sur 23096, Mexico
| | - Norma Estrada
- Programa Cátedras CONAHCYT, Centro de Investigaciones Biológicas del Noroeste, S.C. (CIBNOR), Av. I.P.N. 195, Col. Playa Palo de Santa Rita Sur, La Paz, Baja California Sur 23096, Mexico
| | - Rosalba Alonso-Rodríguez
- Unidad Académica Mazatlán, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, P. O. Box 811, Mazatlán, Sinaloa 82040, Mexico.
| | - Felipe Ascencio
- Centro de Investigaciones Biológicas del Noroeste, S.C. (CIBNOR), Av. I.P.N. 195, Col. Playa Palo de Santa Rita Sur, La Paz, Baja California Sur 23096, Mexico
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Montuori E, De Luca D, Penna A, Stalberga D, Lauritano C. Alexandrium spp.: From Toxicity to Potential Biotechnological Benefits. Mar Drugs 2023; 22:31. [PMID: 38248656 PMCID: PMC10821459 DOI: 10.3390/md22010031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/27/2023] [Accepted: 12/28/2023] [Indexed: 01/23/2024] Open
Abstract
Many dinoflagellates of the genus Alexandrium are well known for being responsible for harmful algal blooms (HABs), producing potent toxins that cause damages to other marine organisms, aquaculture, fishery, tourism, as well as induce human intoxications and even death after consumption of contaminated shellfish or fish. In this review, we summarize potential bioprospecting associated to the genus Alexandrium, including which Alexandrium spp. produce metabolites with anticancer, antimicrobial, antiviral, as well as anti-Alzheimer applications. When available, we report their mechanisms of action and targets. We also discuss recent progress on the identification of secondary metabolites with biological properties favorable to human health and aquaculture. Altogether, this information highlights the importance of studying which culturing conditions induce the activation of enzymatic pathways responsible for the synthesis of bioactive metabolites. It also suggests considering and comparing clones collected in different locations for toxin monitoring and marine bioprospecting. This review can be of interest not only for the scientific community, but also for the entire population and industries.
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Affiliation(s)
- Eleonora Montuori
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale F. Stagno d’Alcontres 31, 98166 Messina, Italy;
- Department of Ecosustainable Marine Biotechnology, Stazione Zoologica Anton Dohrn, Via Acton 55, 80133 Napoli, Italy
| | - Daniele De Luca
- Research Infrastructure for Marine Biological Resources Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy;
| | - Antonella Penna
- Department of Biomolecular Sciences, University of Urbino, Campus E. Mattei, 61029 Urbino, Italy;
| | - Darta Stalberga
- Department of Biomedical and Clinical Sciences, Division of Clinical Chemistry and Pharmacology, Linköping University, SE-58183 Linköping, Sweden;
| | - Chiara Lauritano
- Department of Ecosustainable Marine Biotechnology, Stazione Zoologica Anton Dohrn, Via Acton 55, 80133 Napoli, Italy
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Song W, Song X, Chi L, Zhu J, Cao X, Yu Z. Novel insights into toxin changes associated with the growth of Alexandrium pacificum: Revealing active toxin-secretion ability and toxin cell quota variation. HARMFUL ALGAE 2023; 129:102516. [PMID: 37951610 DOI: 10.1016/j.hal.2023.102516] [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: 05/15/2023] [Revised: 08/13/2023] [Accepted: 09/25/2023] [Indexed: 11/14/2023]
Abstract
Paralytic shellfish toxins (PSTs) are widely distributed globally and are produced by Alexandrium pacificum in marine system. However, the characteristics of toxins producing and secreting associated with growth phases are still unclear, especially whether A. pacificum has the ability to actively secrete PSTs is controversial. In this study, variation characteristics of intracellular and extracellular PSTs contents associated with A. pacificum growth phases were investigated thoroughly. The results showed that intracellular and extracellular PSTs contents increased sharply during the exponential phase. But during the stationary phase, the intracellular PSTs content increased by only 26 %, and the extracellular PSTs content did not increase significantly. Since the increase in extracellular PSTs content mainly occurred at the exponential phase, when most cells were living, we speculated that active PSTs secretion of living cells might be an important production pathway of extracellular toxins besides leakage from dead cells. Furthermore, toxin cell quota variation associated with the growth phase was analysed. In the exponential phase, the toxin cell quota first increased and then decreased, with a maximum of 19.02 ± 1.80 fmol/cell at 6 d. However, after entering the stationary phase, this value slowly increased again, suggesting that vigilance should be raised for the plateau of Alexandrium blooms. In addition, cells in the exponential phase mainly produced O-sulfated components such as GTX1&4, cells in the stationary phase mainly produced O-sulfate-free components such as GTX5. In this study, the toxigenic rules of A. pacificum were comprehensively uncovered, which provided theoretical guidance for the prevention and mitigation of A. pacificum blooms.
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Affiliation(s)
- Weijia Song
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Xiuxian Song
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China.
| | - Lianbao Chi
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Jianan Zhu
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Xihua Cao
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Zhiming Yu
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
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15
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Akbar MA, Mohd Yusof NY, Usup G, Ahmad A, Baharum SN, Bunawan H. Nutrient Deficiencies Impact on the Cellular and Metabolic Responses of Saxitoxin Producing Alexandrium minutum: A Transcriptomic Perspective. Mar Drugs 2023; 21:497. [PMID: 37755110 PMCID: PMC10532982 DOI: 10.3390/md21090497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 07/11/2023] [Accepted: 07/12/2023] [Indexed: 09/28/2023] Open
Abstract
Dinoflagellate Alexandrium minutum Halim is commonly associated with harmful algal blooms (HABs) in tropical marine waters due to its saxitoxin production. However, limited information is available regarding the cellular and metabolic changes of A. minutum in nutrient-deficient environments. To fill this gap, our study aimed to investigate the transcriptomic responses of A. minutum under nitrogen and phosphorus deficiency. The induction of nitrogen and phosphorus deficiency resulted in the identification of 1049 and 763 differently expressed genes (DEGs), respectively. Further analysis using gene set enrichment analysis (GSEA) revealed 702 and 1251 enriched gene ontology (GO) terms associated with nitrogen and phosphorus deficiency, respectively. Our results indicate that in laboratory cultures, nitrogen deficiency primarily affects meiosis, carbohydrate catabolism, ammonium assimilation, ion homeostasis, and protein kinase activity. On the other hand, phosphorus deficiency primarily affects the carbon metabolic response, cellular ion transfer, actin-dependent cell movement, signalling pathways, and protein recycling. Our study provides valuable insights into biological processes and genes regulating A. minutum's response to nutrient deficiencies, furthering our understanding of the ecophysiological response of HABs to environmental change.
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Affiliation(s)
- Muhamad Afiq Akbar
- Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia
- Aquatic Animal Health and Therapeutics Laboratory, Institute of Bioscience, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia
- Institute of System Biology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia;
| | - Nurul Yuziana Mohd Yusof
- Department of Earth Science and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia; (N.Y.M.Y.); (G.U.)
| | - Gires Usup
- Department of Earth Science and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia; (N.Y.M.Y.); (G.U.)
| | - Asmat Ahmad
- Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia;
| | - Syarul Nataqain Baharum
- Institute of System Biology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia;
| | - Hamidun Bunawan
- Institute of System Biology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia;
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16
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Abassi S, Kim HS, Bui QTN, Ki JS. Effects of nitrate on the saxitoxins biosynthesis revealed by sxt genes in the toxic dinoflagellate Alexandrium pacificum (group IV). HARMFUL ALGAE 2023; 127:102473. [PMID: 37544673 DOI: 10.1016/j.hal.2023.102473] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 06/09/2023] [Accepted: 06/10/2023] [Indexed: 08/08/2023]
Abstract
The dinoflagellate Alexandrium pacificum (group IV) is of particular interest because of its involvement in harmful algal blooms and production of saxitoxin (STX), which causes paralytic shellfish poisoning. The toxicity from STX and its analogues (STXs) is suspected to be affected by nitrogen (N) availability. However, the toxicity-associated behavior and STX-biosynthesis gene responses of the toxic A. pacificum under N fluctuations have not been sufficiently investigated. In the present study, we identified the sxtI gene involved in sxt biosynthesis pathway and evaluated the effects of nitrate (NO3-) on STXs production and the expression of four sxt core genes (sxtA4, sxtG, sxtB, and sxtI). Quantification of total STXs levels in the cultures under different NO3- regimes showed that NO3- concentration influenced STXs production. In addition, the proportion and concentration of STXs varied depending on the NO3- concentration. Core sxt transcript abundance was also influenced by available NO3- in a time-dependent manner. Expressional levels and patterns of sxtI were correlated with those of sxtA and sxtB. The relationship between the toxins and sxt responses in A. pacificum under various NO3- regimes suggests the direct involvement of N in the STXs biosynthesis pathway. Understanding this link would provide a tool to understand the toxin dynamics of dinoflagellates following N shifts in marine environments.
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Affiliation(s)
- Sofia Abassi
- Department of Biotechnology, Sangmyung University, Seoul, 03016, Republic of Korea
| | - Han-Sol Kim
- Department of Biotechnology, Sangmyung University, Seoul, 03016, Republic of Korea
| | - Quynh Thi Nhu Bui
- Department of Biotechnology, Sangmyung University, Seoul, 03016, Republic of Korea
| | - Jang-Seu Ki
- Department of Biotechnology, Sangmyung University, Seoul, 03016, Republic of Korea.
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17
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Bashir F, Bashir A, Bouaïcha N, Chen L, Codd GA, Neilan B, Xu WL, Ziko L, Rajput VD, Minkina T, Arruda RS, Ganai BA. Cyanotoxins, biosynthetic gene clusters, and factors modulating cyanotoxin biosynthesis. World J Microbiol Biotechnol 2023; 39:241. [PMID: 37394567 DOI: 10.1007/s11274-023-03652-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 05/17/2023] [Indexed: 07/04/2023]
Abstract
Cyanobacterial harmful algal blooms (CHABs) are a global environmental concern that encompasses public health issues, water availability, and water quality owing to the production of various secondary metabolites (SMs), including cyanotoxins in freshwater, brackish water, and marine ecosystems. The frequency, extent, magnitude, and duration of CHABs are increasing globally. Cyanobacterial species traits and changing environmental conditions, including anthropogenic pressure, eutrophication, and global climate change, together allow cyanobacteria to thrive. The cyanotoxins include a diverse range of low molecular weight compounds with varying biochemical properties and modes of action. With the application of modern molecular biology techniques, many important aspects of cyanobacteria are being elucidated, including aspects of their diversity, gene-environment interactions, and genes that express cyanotoxins. The toxicological, environmental, and economic impacts of CHABs strongly advocate the need for continuing, extensive efforts to monitor cyanobacterial growth and to understand the mechanisms regulating species composition and cyanotoxin biosynthesis. In this review, we critically examined the genomic organization of some cyanobacterial species that lead to the production of cyanotoxins and their characteristic properties discovered to date.
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Affiliation(s)
- Fahim Bashir
- Department of Environmental Science, University of Kashmir, Srinagar, Jammu and Kashmir, 190006, India
| | - Arif Bashir
- Department of Clinical Biochemistry and Biotechnology, Government College for Women, Nawa-Kadal, Srinagar, Jammu & Kashmir, India
| | - Noureddine Bouaïcha
- Laboratory Ecology, Systematic, and Evolution, UMR 8079 Univ. Paris-Sud, CNRS, AgroParisTech, University Paris-Saclay, 91190, Gif-sur-Yvette, France.
| | - Liang Chen
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science (SEES), Yunnan University (YNU), 650500, Kunming, China.
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology (IHB), Chinese Academy of Sciences (CAS), Wuhan, 430072, China.
- State Key Laboratory of Eco-Hydraulics in Northwest Arid Region, Faculty of Water Resources and Hydroelectric Engineering, Xi'an University of Technology, Xi'an, 710048, China.
| | - Geoffrey A Codd
- Biological and Environmental Sciences, University of Stirling, Stirling, FK9 4LA, Scotland, UK
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, Scotland, UK
| | - Brett Neilan
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, Australia
| | - Wen-Li Xu
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology (IHB), Chinese Academy of Sciences (CAS), Wuhan, 430072, China
| | - Laila Ziko
- School of Life and Medical Sciences, University of Hertfordshire Hosted By Global Academic Foundation, Cairo, Egypt
- Biology Department, School of Sciences and Engineering, The American University in Cairo, New Cairo, 11835, Egypt
| | - Vishnu D Rajput
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-On-Don, Russia
| | - Tatiana Minkina
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-On-Don, Russia
| | - Renan Silva Arruda
- Laboratory of Ecology and Physiology of Phytoplankton, Department of Plant Biology, University of Rio de Janeiro State, Rio de Janeiro, Brazil
| | - Bashir Ahmad Ganai
- Center of Research for Development (CORD), University of Kashmir, Srinagar, Jammu and Kashmir, 190006, India.
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18
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Song W, Song X, Cheng R, Chi L, Zhu J, Yu Z. Uncovering the regulation effect of modified clay on toxin production in Alexandrium pacificum: From physiological insights. JOURNAL OF HAZARDOUS MATERIALS 2023; 454:131516. [PMID: 37146321 DOI: 10.1016/j.jhazmat.2023.131516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 04/20/2023] [Accepted: 04/25/2023] [Indexed: 05/07/2023]
Abstract
As a common dinoflagellate, Alexandrium pacificum can produce paralytic shellfish toxins (PSTs). It can be removed from water by Polyaluminium chloride modified clay (PAC-MC), but it is unclear whether PAC-MC can prevent PSTs content and toxicity from increasing and whether PAC-MC can stimulate PSTs biosynthesis by A. pacificum. Effect of PAC-MC on PSTs and the physiological mechanism were analysed here. The results showed total PSTs content and toxicity decreased respectively by 34.10 % and 48.59 % in 0.2 g/L PAC-MC group at 12 days compared with control group. And the restriction of total PSTs by PAC-MC was mainly achieved via inhibition of algal cell proliferation, by affecting A. pacificum physiological processes and changing phycosphere microbial community. Meanwhile, single-cell PSTs toxicity did not increase significantly throughout the experiment. Moreover, A. pacificum treated with PAC-MC tended to synthesize sulfated PSTs such as C1&2. Mechanistic analysis showed that PAC-MC induced upregulation of sulfotransferase sxtN (related to PSTs sulfation), and functional prediction of bacterial community also showed significant enrichment of "sulfur relay system" after PAC-MC treatment, which might also promote PSTs sulfation. The results will provide theoretical guidance for the application of PAC-MC to field control of toxic Alexandrium blooms.
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Affiliation(s)
- Weijia Song
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Xiuxian Song
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China.
| | - Ruihong Cheng
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Lianbao Chi
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Jianan Zhu
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Zhiming Yu
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
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19
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Song W, Song X, Shen H, Ding Y, Cheng R, Yu Z. Degradation of paralytic shellfish toxins during flocculation of Alexandrium pacificum by an oxidized modified clay: A laboratory experiment. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 253:114667. [PMID: 36822061 DOI: 10.1016/j.ecoenv.2023.114667] [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: 10/24/2022] [Revised: 02/07/2023] [Accepted: 02/17/2023] [Indexed: 06/18/2023]
Abstract
Paralytic shellfish toxins (PSTs), produced by Alexandrium pacificum in the marine environment, are a group of potent neurotoxins which specifically block voltage-gated sodium channels in excitable cells. During the toxigenic A. pacificum blooms outbreaks, PSTs can be accumulated through the food chain and finally enter the human body, posing a significant threat to human health and safety. This study experimented with a novel type of oxidized modified clay, potassium peroxymonosulfate modified clay (PMPS-MC), which could remove A. pacificum cells as well as reduce intracellular and extracellular PSTs toxicity rapidly. For the extracellular PSTs, its content decreased to below the detection limit rapidly through oxidative degradation within 15 min of 10 mg/L PMPS-MC treatment. Whereafter, although the residual cells in water column and some viable cells in flocculated sediment continued to secrete toxins, the extracellular PSTs content and toxicity in the PMPS-MC treatment groups remained significantly lower than those in the control group. For the intracellular PSTs, PMPS-MC might induce the transformation of more toxic GTX1&4 to less toxic GTX2&3 and C1&2, resulting in intracellular PSTs toxicity reduced within 15 min. In addition, intracellular PSTs content and toxicity in the PMPS-MC treatment groups were consistently lower than the control group within 48 h, possibly by inhibiting the A. pacificum cells growth. These results will provide a scientific basis for the field application of modified clay to control A. pacificum blooms.
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Affiliation(s)
- Weijia Song
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Xiuxian Song
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China.
| | - Huihui Shen
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Yu Ding
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Ruihong Cheng
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Zhiming Yu
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
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20
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Cheng R, Song X, Song W, Yu Z. A New Perspective: Revealing the Algicidal Properties of Bacillus subtilis to Alexandrium pacificum from Bacterial Communities and Toxins. Mar Drugs 2022; 20:md20100624. [PMID: 36286448 PMCID: PMC9605167 DOI: 10.3390/md20100624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/23/2022] [Accepted: 09/26/2022] [Indexed: 11/29/2022] Open
Abstract
Algicidal bacteria are important in the control of toxic dinoflagellate blooms, but studies on the environmental behavior of related algal toxins are still lacking. In this study, Bacillus subtilis S3 (S3) showed the highest algicidal activity against Alexandrium pacificum (Group IV) out of six Bacillus strains. When treated with 0.5% (v/v) S3 bacterial culture and sterile supernatant, the algicidal rates were 69.74% and 70.22% at 12 h, respectively, and algicidal substances secreted by S3 were considered the mechanism of algicidal effect. During the algicidal process, the rapid proliferation of Alteromonas sp. in the phycosphere of A. pacificum may have accelerated the algal death. Moreover, the algicidal development of S3 released large amounts of intracellular paralytic shellfish toxins (PSTs) into the water, as the extracellular PSTs increased by 187.88% and 231.47% at 12 h, compared with the treatment of bacterial culture and sterile supernatant at 0 h, respectively. Although the total amount of PSTs increased slightly, the total toxicity of the algal sample decreased as GTX1/4 was transformed by S3 into GTX2/3 and GTX5. These results more comprehensively reveal the complex relationship between algicidal bacteria and microalgae, providing a potential source of biological control for harmful algal blooms and toxins.
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Affiliation(s)
- Ruihong Cheng
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Xiuxian Song
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
- Correspondence: ; Tel.: +86-532-82898587
| | - Weijia Song
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Zhiming Yu
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
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21
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Lao Y, Skiba MA, Chun SW, Narayan ARH, Smith JL. Structural Basis for Control of Methylation Extent in Polyketide Synthase Metal-Dependent C-Methyltransferases. ACS Chem Biol 2022; 17:2088-2098. [PMID: 35594521 PMCID: PMC9462956 DOI: 10.1021/acschembio.2c00085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Installation of methyl groups can significantly improve the binding of small-molecule drugs to protein targets; however, site-selective methylation often presents a significant synthetic challenge. Metal- and S-adenosyl-methionine (SAM)-dependent methyltransferases (MTs) in natural-product biosynthetic pathways are powerful enzymatic tools for selective or chemically challenging C-methylation reactions. Each of these MTs selectively catalyzes one or two methyl transfer reactions. Crystal structures and biochemical assays of the Mn2+-dependent monomethyltransferase from the saxitoxin biosynthetic pathway (SxtA MT) revealed the structural basis for control of methylation extent. The SxtA monomethyltransferase was converted to a dimethyltransferase by modification of the metal binding site, addition of an active site base, and an amino acid substitution to provide space in the substrate pocket for two methyl substituents. A reciprocal change converted a related dimethyltransferase into a monomethyltransferase, supporting our hypothesis that steric hindrance can prevent a second methylation event. A novel understanding of MTs will accelerate the development of MT-based catalysts and MT engineering for use in small-molecule synthesis.
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Affiliation(s)
- Yongtong Lao
- Program in Chemical Biology, University of Michigan, Ann Arbor, Michigan 48109, United States
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Meredith A Skiba
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Stephanie W Chun
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Alison R H Narayan
- Program in Chemical Biology, University of Michigan, Ann Arbor, Michigan 48109, United States
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Janet L Smith
- Program in Chemical Biology, University of Michigan, Ann Arbor, Michigan 48109, United States
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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22
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Identification of novel paralytic shellfish toxin binding protein via homology modeling and molecular docking. Toxicon 2022; 211:61-69. [DOI: 10.1016/j.toxicon.2022.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 02/21/2022] [Accepted: 03/14/2022] [Indexed: 11/21/2022]
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23
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Thi Nhu Bui Q, Kim H, Wang H, Ki JS. Unveiling the genomic structures and evolutionary events of the saxitoxin biosynthetic gene sxtA in the marine toxic dinoflagellate Alexandrium. Mol Phylogenet Evol 2022; 168:107417. [PMID: 35031458 DOI: 10.1016/j.ympev.2022.107417] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 11/24/2021] [Accepted: 12/27/2021] [Indexed: 12/30/2022]
Abstract
Marine dinoflagellates Alexandriumare known to produce saxitoxin (STX) and cause paralytic shellfish poisoning (PSP) which can result in mortality in human. SxtA is considered a core gene for the biosynthesis of STX. However, its gene coding structure and evolutionary history have yet to be fully elucidated. Here, we determined the full-length sequences of sxtA cDNA and genomic coding regions from two toxic dinoflagellates, Alexandrium catenella (LIMS-PS-2645 and LIMS-PS-2647) andA. pacificum (LMBE-C4), characterised their domain structures, and resolved evolutionary events. The sxtA gene was encoded on the genome without introns, and was identical in length (4002 bp) between two A. catenella strains, but their sequences differed from A. pacificum (5031 bp). SxtA consists of four domains, sxtA1, sxtA2, sxtA3, and sxtA4; however, A. pacificum has an extra domain TauD near sxtA1. Each domain had >64.4% GC content, with the highest being 71.6% in sxtA3. Molecular divergence was found to be significantly higher in sxtA4 than in the other domains. Phylogenetic trees of sxtA and separate domains showed that bacteria diverged earliest, followed by non-toxic, toxic cyanobacteria, toxic dinoflagellates. While sxtA domains in Alexandrium were similar to the PKS-like structure with the conserved sxtA1, sxtA2, and sxtA3. PKS_KS may be replaced by sxtA4 in toxic Alexandrium. These suggest that sxtA in Alexandrium may have evolved by acquiring specific domains, whose modification and complexity markedly affect toxin biosynthesis.
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Affiliation(s)
- Quynh Thi Nhu Bui
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea
| | - Hansol Kim
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea
| | - Hui Wang
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea; Hunan Province Key Laboratory of Typical Environmental Pollution and Health Hazards, School of Public Health, University of South China, Hengyang 421001, China
| | - Jang-Seu Ki
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea.
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Bui QTN, Kim H, Park H, Ki JS. Salinity Affects Saxitoxins (STXs) Toxicity in the Dinoflagellate Alexandrium pacificum, with Low Transcription of SXT-Biosynthesis Genes sxtA4 and sxtG. Toxins (Basel) 2021; 13:toxins13100733. [PMID: 34679026 PMCID: PMC8539879 DOI: 10.3390/toxins13100733] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 10/13/2021] [Accepted: 10/15/2021] [Indexed: 01/23/2023] Open
Abstract
Salinity is an important factor for regulating metabolic processes in aquatic organisms; however, its effects on toxicity and STX biosynthesis gene responses in dinoflagellates require further elucidation. Herein, we evaluated the physiological responses, toxin production, and expression levels of two STX synthesis core genes, sxtA4 and sxtG, in the dinoflagellate Alexandrium pacificum Alex05 under different salinities (20, 25, 30, 35, and 40 psu). Optimal growth was observed at 30 psu (0.12 cell division/d), but cell growth significantly decreased at 20 psu and was irregular at 25 and 40 psu. The cell size increased at lower salinities, with the highest size of 31.5 µm at 20 psu. STXs eq was highest (35.8 fmol/cell) in the exponential phase at 30 psu. GTX4 and C2 were predominant at that time but were replaced by GTX1 and NeoSTX in the stationary phase. However, sxtA4 and sxtG mRNAs were induced, and their patterns were similar in all tested conditions. PCA showed that gene transcriptional levels were not correlated with toxin contents and salinity. These results suggest that A. pacificum may produce the highest amount of toxins at optimal salinity, but sxtA4 and sxtG may be only minimally affected by salinity, even under high salinity stress.
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Affiliation(s)
- Quynh Thi Nhu Bui
- Department of Biotechnology, Sangmyung University, Seoul 03016, Korea
| | - Hansol Kim
- Department of Biotechnology, Sangmyung University, Seoul 03016, Korea
| | - Hyunjun Park
- Department of Biotechnology, Sangmyung University, Seoul 03016, Korea
| | - Jang-Seu Ki
- Department of Biotechnology, Sangmyung University, Seoul 03016, Korea
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Naknaen A, Ratsameepakai W, Suttinun O, Sukpondma Y, Khan E, Pomwised R. Microcystis Sp. Co-Producing Microcystin and Saxitoxin from Songkhla Lake Basin, Thailand. Toxins (Basel) 2021; 13:toxins13090631. [PMID: 34564635 PMCID: PMC8472854 DOI: 10.3390/toxins13090631] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 09/01/2021] [Accepted: 09/03/2021] [Indexed: 11/16/2022] Open
Abstract
The Songkhla Lake Basin (SLB) located in Southern Thailand, has been increasingly polluted by urban and industrial wastewater, while the lake water has been intensively used. Here, we aimed to investigate cyanobacteria and cyanotoxins in the SLB. Ten cyanobacteria isolates were identified as Microcystis genus based on16S rDNA analysis. All isolates harbored microcystin genes, while five of them carried saxitoxin genes. On day 15 of culturing, the specific growth rate and Chl-a content were 0.2-0.3 per day and 4 µg/mL. The total extracellular polymeric substances (EPS) content was 0.37-0.49 µg/mL. The concentration of soluble EPS (sEPS) was 2 times higher than that of bound EPS (bEPS). The protein proportion in both sEPS and bEPS was higher than the carbohydrate proportion. The average of intracellular microcystins (IMCs) was 0.47 pg/cell on day 15 of culturing, while extracellular microcystins (EMCs) were undetectable. The IMCs were dramatically produced at the exponential phase, followed by EMCs release at the late exponential phase. On day 30, the total microcystins (MCs) production reached 2.67 pg/cell. Based on liquid chromatograph-quadrupole time-of-flight mass spectrometry, three new MCs variants were proposed. This study is the first report of both decarbamoylsaxitoxin (dcSTX) and new MCs congeners synthesized by Microcystis.
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Affiliation(s)
- Ampapan Naknaen
- Environmental Assessment and Technology for Hazardous Waste Management Research Center, Faculty of Environmental Management, Prince of Songkla University, Hat Yai 90110, Thailand; (A.N.); (O.S.)
| | - Waraporn Ratsameepakai
- Office of Scientific Instrument and Testing, Prince of Songkla University, Hat Yai 90110, Thailand;
| | - Oramas Suttinun
- Environmental Assessment and Technology for Hazardous Waste Management Research Center, Faculty of Environmental Management, Prince of Songkla University, Hat Yai 90110, Thailand; (A.N.); (O.S.)
- Center of Excellence on Hazardous Substance Management (HSM), Bangkok 10330, Thailand
| | - Yaowapa Sukpondma
- Division of Physical Science, Faculty of Science, Prince of Songkla University, Hat Yai 90110, Thailand;
| | - Eakalak Khan
- Department of Civil and Environmental Engineering and Construction, University of Nevada, Las Vegas, NV 89154-4015, USA;
| | - Rattanaruji Pomwised
- Division of Biological Science, Faculty of Science, Prince of Songkla University, Hat Yai 90110, Thailand
- Correspondence: ; Tel.: +66-74-288-325
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26
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Chan KKY, Kong HK, Tse SPK, Chan Z, Lo PY, Kwok KWH, Lo SCL. Finding Species-Specific Extracellular Surface-Facing Proteomes in Toxic Dinoflagellates. Toxins (Basel) 2021; 13:624. [PMID: 34564629 PMCID: PMC8473415 DOI: 10.3390/toxins13090624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/31/2021] [Accepted: 09/01/2021] [Indexed: 11/27/2022] Open
Abstract
As a sequel to our previous report of the existence of species-specific protein/peptide expression profiles (PEPs) acquired by mass spectrometry in some dinoflagellates, we established, with the help of a plasma-membrane-impermeable labeling agent, a surface amphiesmal protein extraction method (SAPE) to label and capture species-specific surface proteins (SSSPs) as well as saxitoxins-producing-species-specific surface proteins (Stx-SSPs) that face the extracellular space (i.e., SSSPsEf and Stx-SSPsEf). Five selected toxic dinoflagellates, Alexandrium minutum, A. lusitanicum, A. tamarense, Gymnodinium catenatum, and Karenia mikimotoi, were used in this study. Transcriptomic databases of these five species were also constructed. With the aid of liquid chromatography linked-tandem mass spectrometry (LC-MS/MS) and the transcriptomic databases of these species, extracellularly facing membrane proteomes of the five different species were identified. Within these proteomes, 16 extracellular-facing and functionally significant transport proteins were found. Furthermore, 10 SSSPs and 6 Stx-SSPs were identified as amphiesmal proteins but not facing outward to the extracellular environment. We also found SSSPsEf and Stx-SSPsEf in the proteomes. The potential functional correlation of these proteins towards the production of saxitoxins in dinoflagellates and the degree of species specificity were discussed accordingly.
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Affiliation(s)
- Kenrick Kai-yuen Chan
- Department of Applied Biology and Chemical Technology, Faculty of Applied Science and Textiles, The Hong Kong Polytechnic University, Hung Hom, Hong Kong; (K.K.-y.C.); (H.-k.K.); (S.P.-k.T.); (Z.C.); (P.-y.L.); (K.W.H.K.)
| | - Hang-kin Kong
- Department of Applied Biology and Chemical Technology, Faculty of Applied Science and Textiles, The Hong Kong Polytechnic University, Hung Hom, Hong Kong; (K.K.-y.C.); (H.-k.K.); (S.P.-k.T.); (Z.C.); (P.-y.L.); (K.W.H.K.)
- Research Institute for Future Food, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Sirius Pui-kam Tse
- Department of Applied Biology and Chemical Technology, Faculty of Applied Science and Textiles, The Hong Kong Polytechnic University, Hung Hom, Hong Kong; (K.K.-y.C.); (H.-k.K.); (S.P.-k.T.); (Z.C.); (P.-y.L.); (K.W.H.K.)
| | - Zoe Chan
- Department of Applied Biology and Chemical Technology, Faculty of Applied Science and Textiles, The Hong Kong Polytechnic University, Hung Hom, Hong Kong; (K.K.-y.C.); (H.-k.K.); (S.P.-k.T.); (Z.C.); (P.-y.L.); (K.W.H.K.)
| | - Pak-yeung Lo
- Department of Applied Biology and Chemical Technology, Faculty of Applied Science and Textiles, The Hong Kong Polytechnic University, Hung Hom, Hong Kong; (K.K.-y.C.); (H.-k.K.); (S.P.-k.T.); (Z.C.); (P.-y.L.); (K.W.H.K.)
| | - Kevin W. H. Kwok
- Department of Applied Biology and Chemical Technology, Faculty of Applied Science and Textiles, The Hong Kong Polytechnic University, Hung Hom, Hong Kong; (K.K.-y.C.); (H.-k.K.); (S.P.-k.T.); (Z.C.); (P.-y.L.); (K.W.H.K.)
- Research Institute for Future Food, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Samuel Chun-lap Lo
- Department of Applied Biology and Chemical Technology, Faculty of Applied Science and Textiles, The Hong Kong Polytechnic University, Hung Hom, Hong Kong; (K.K.-y.C.); (H.-k.K.); (S.P.-k.T.); (Z.C.); (P.-y.L.); (K.W.H.K.)
- Research Institute for Future Food, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
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27
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Boullot F, Fabioux C, Hégaret H, Boudry P, Soudant P, Benoit E. Electrophysiological Evaluation of Pacific Oyster ( Crassostrea gigas) Sensitivity to Saxitoxin and Tetrodotoxin. Mar Drugs 2021; 19:md19070380. [PMID: 34209313 PMCID: PMC8307532 DOI: 10.3390/md19070380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 06/23/2021] [Accepted: 06/27/2021] [Indexed: 12/17/2022] Open
Abstract
Pacific oysters (Crassostrea gigas) may bio-accumulate high levels of paralytic shellfish toxins (PST) during harmful algal blooms of the genus Alexandrium. These blooms regularly occur in coastal waters, affecting oyster health and marketability. The aim of our study was to analyse the PST-sensitivity of nerves of Pacific oysters in relation with toxin bio-accumulation. The results show that C. gigas nerves have micromolar range of saxitoxin (STX) sensitivity, thus providing intermediate STX sensitivity compared to other bivalve species. However, theses nerves were much less sensitive to tetrodotoxin. The STX-sensitivity of compound nerve action potential (CNAP) recorded from oysters experimentally fed with Alexandrium minutum (toxic-alga-exposed oysters), or Tisochrysis lutea, a non-toxic microalga (control oysters), revealed that oysters could be separated into STX-resistant and STX-sensitive categories, regardless of the diet. Moreover, the percentage of toxin-sensitive nerves was lower, and the STX concentration necessary to inhibit 50% of CNAP higher, in recently toxic-alga-exposed oysters than in control bivalves. However, no obvious correlation was observed between nerve sensitivity to STX and the STX content in oyster digestive glands. None of the nerves isolated from wild and farmed oysters was detected to be sensitive to tetrodotoxin. In conclusion, this study highlights the good potential of cerebrovisceral nerves of Pacific oysters for electrophysiological and pharmacological studies. In addition, this study shows, for the first time, that C. gigas nerves have micromolar range of STX sensitivity. The STX sensitivity decreases, at least temporary, upon recent oyster exposure to dinoflagellates producing PST under natural, but not experimental environment.
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Affiliation(s)
- Floriane Boullot
- Service d’Ingénierie Moléculaire Pour la Santé (SIMoS), Département Médicaments et Technologies Pour la Santé (DMTS), Institut des Sciences du Vivant Frédéric Joliot, Université Paris-Saclay, CEA, ERL CNRS/CEA 9004, 91191 Gif-sur-Yvette, France;
- Laboratoire des Sciences de l’Environnement Marin (LEMAR), Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, UMR 6539 CNRS/UBO/IRD/Ifremer, 29280 Plouzané, France; (C.F.); (H.H.); (P.S.)
| | - Caroline Fabioux
- Laboratoire des Sciences de l’Environnement Marin (LEMAR), Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, UMR 6539 CNRS/UBO/IRD/Ifremer, 29280 Plouzané, France; (C.F.); (H.H.); (P.S.)
| | - Hélène Hégaret
- Laboratoire des Sciences de l’Environnement Marin (LEMAR), Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, UMR 6539 CNRS/UBO/IRD/Ifremer, 29280 Plouzané, France; (C.F.); (H.H.); (P.S.)
| | - Pierre Boudry
- Centre Ifremer Bretagne, Ifremer, UMR 6539 (LEMAR) CNRS/UBO/IRD/Ifremer, ZI de la Pointe du Diable, CS 10070, 29280 Plouzané, France;
| | - Philippe Soudant
- Laboratoire des Sciences de l’Environnement Marin (LEMAR), Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, UMR 6539 CNRS/UBO/IRD/Ifremer, 29280 Plouzané, France; (C.F.); (H.H.); (P.S.)
| | - Evelyne Benoit
- Service d’Ingénierie Moléculaire Pour la Santé (SIMoS), Département Médicaments et Technologies Pour la Santé (DMTS), Institut des Sciences du Vivant Frédéric Joliot, Université Paris-Saclay, CEA, ERL CNRS/CEA 9004, 91191 Gif-sur-Yvette, France;
- Correspondence:
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Vilar MCP, Rodrigues TFCP, Silva LO, Pacheco ABF, Ferrão-Filho AS, Azevedo SMFO. Ecophysiological Aspects and sxt Genes Expression Underlying Induced Chemical Defense in STX-Producing Raphidiopsis raciborskii (Cyanobacteria) against the Zooplankter Daphnia gessneri. Toxins (Basel) 2021; 13:406. [PMID: 34200983 PMCID: PMC8230027 DOI: 10.3390/toxins13060406] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 05/31/2021] [Accepted: 06/02/2021] [Indexed: 11/16/2022] Open
Abstract
Cyanobacteria stand out among phytoplankton when they form massive blooms and produce toxins. Because cyanotoxin genes date to the origin of metazoans, the hypothesis that cyanotoxins function as a defense against herbivory is still debated. Although their primary cellular function might vary, these metabolites could have evolved as an anti-predator response. Here we evaluated the physiological and molecular responses of a saxitoxin-producing Raphidiopsis raciborskii to infochemicals released by the grazer Daphnia gessneri. Induced chemical defenses were evidenced in R. raciborskii as a significant increase in the transcription level of sxt genes, followed by an increase in saxitoxin content when exposed to predator cues. Moreover, cyanobacterial growth decreased, and no significant effects on photosynthesis or morphology were observed. Overall, the induced defense response was accompanied by a trade-off between toxin production and growth. These results shed light on the mechanisms underlying zooplankton-cyanobacteria interactions in aquatic food webs. The widespread occurrence of the cyanobacterium R. raciborskii in freshwater bodies has been attributed to its phenotypic plasticity. Assessing the potential of this species to thrive over interaction filters such as zooplankton grazing pressure can enhance our understanding of its adaptive success.
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Affiliation(s)
- Mauro C. P. Vilar
- Laboratory Ecophysiology and Toxicology of Cyanobacteria, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro 21949-902, Brazil; (T.F.C.P.R.); (L.O.S.); (S.M.F.O.A.)
| | - Thiago F. C. P. Rodrigues
- Laboratory Ecophysiology and Toxicology of Cyanobacteria, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro 21949-902, Brazil; (T.F.C.P.R.); (L.O.S.); (S.M.F.O.A.)
| | - Luan O. Silva
- Laboratory Ecophysiology and Toxicology of Cyanobacteria, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro 21949-902, Brazil; (T.F.C.P.R.); (L.O.S.); (S.M.F.O.A.)
| | - Ana Beatriz F. Pacheco
- Laboratory Biological Physics, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro 21949-902, Brazil;
| | - Aloysio S. Ferrão-Filho
- Laboratory of Evaluation and Promotion of Environmental Health, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro 21040-360, Brazil;
| | - Sandra M. F. O. Azevedo
- Laboratory Ecophysiology and Toxicology of Cyanobacteria, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro 21949-902, Brazil; (T.F.C.P.R.); (L.O.S.); (S.M.F.O.A.)
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Geffroy S, Lechat MM, Le Gac M, Rovillon GA, Marie D, Bigeard E, Malo F, Amzil Z, Guillou L, Caruana AMN. From the sxtA4 Gene to Saxitoxin Production: What Controls the Variability Among Alexandrium minutum and Alexandrium pacificum Strains? Front Microbiol 2021; 12:613199. [PMID: 33717003 PMCID: PMC7944994 DOI: 10.3389/fmicb.2021.613199] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 02/03/2021] [Indexed: 12/22/2022] Open
Abstract
Paralytic shellfish poisoning (PSP) is a human foodborne syndrome caused by the consumption of shellfish that accumulate paralytic shellfish toxins (PSTs, saxitoxin group). In PST-producing dinoflagellates such as Alexandrium spp., toxin synthesis is encoded in the nuclear genome via a gene cluster (sxt). Toxin production is supposedly associated with the presence of a 4th domain in the sxtA gene (sxtA4), one of the core genes of the PST gene cluster. It is postulated that gene expression in dinoflagellates is partially constitutive, with both transcriptional and post-transcriptional processes potentially co-occurring. Therefore, gene structure and expression mode are two important features to explore in order to fully understand toxin production processes in dinoflagellates. In this study, we determined the intracellular toxin contents of twenty European Alexandrium minutum and Alexandrium pacificum strains that we compared with their genome size and sxtA4 gene copy numbers. We observed a significant correlation between the sxtA4 gene copy number and toxin content, as well as a moderate positive correlation between the sxtA4 gene copy number and genome size. The 18 toxic strains had several sxtA4 gene copies (9-187), whereas only one copy was found in the two observed non-toxin producing strains. Exploration of allelic frequencies and expression of sxtA4 mRNA in 11 A. minutum strains showed both a differential expression and specific allelic forms in the non-toxic strains compared with the toxic ones. Also, the toxic strains exhibited a polymorphic sxtA4 mRNA sequence between strains and between gene copies within strains. Finally, our study supported the hypothesis of a genetic determinism of toxin synthesis (i.e., the existence of several genetic isoforms of the sxtA4 gene and their copy numbers), and was also consistent with the hypothesis that constitutive gene expression and moderation by transcriptional and post-transcriptional regulation mechanisms are the cause of the observed variability in the production of toxins by A. minutum.
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Affiliation(s)
| | | | | | | | - Dominique Marie
- Sorbonne Université, CNRS, UMR 7144 Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Roscoff, France
| | - Estelle Bigeard
- Sorbonne Université, CNRS, UMR 7144 Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Roscoff, France
| | | | | | - Laure Guillou
- Sorbonne Université, CNRS, UMR 7144 Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Roscoff, France
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Park G, Dam HG. Cell-growth gene expression reveals a direct fitness cost of grazer-induced toxin production in red tide dinoflagellate prey. Proc Biol Sci 2021; 288:20202480. [PMID: 33563117 DOI: 10.1098/rspb.2020.2480] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Induced prey defences against consumers are conspicuous in microbes, plants and animals. In toxigenic prey, a defence fitness cost should result in a trade-off between defence expression and individual growth. Yet, previous experimental work has failed to detect such induced defence cost in toxigenic phytoplankton. We measured a potential direct fitness cost of grazer-induced toxin production in a red tide dinoflagellate prey using relative gene expression (RGE) of a mitotic cyclin gene (cyc), a marker that correlates to cell growth. This approach disentangles the reduction in cell growth from the defence cost from the mortality by consumers. Treatments where the dinoflagellate Alexandrium catenella were exposed to copepod grazers significantly increased toxin production while decreasing RGE of cyc, indicating a defence-growth trade-off. The defence fitness cost represents a mean decrease of the cell growth rate of 32%. Simultaneously, we estimate that the traditional method to measure mortality loss by consumers is overestimated by 29%. The defence appears adaptive as the prey population persists in quasi steady state after the defence is induced. Our approach provides a novel framework to incorporate the fitness cost of defence in toxigenic prey-consumer interaction models.
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Affiliation(s)
- Gihong Park
- Department of Marine Sciences, University of Connecticut, 1080 Shennecossett Road, Groton, CT 06340, USA
| | - Hans G Dam
- Department of Marine Sciences, University of Connecticut, 1080 Shennecossett Road, Groton, CT 06340, USA
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Vilar MCP, Molica RJR. Changes in pH and dissolved inorganic carbon in water affect the growth, saxitoxins production and toxicity of the cyanobacterium Raphidiopsis raciborskii ITEP-A1. HARMFUL ALGAE 2020; 97:101870. [PMID: 32732056 DOI: 10.1016/j.hal.2020.101870] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 06/17/2020] [Accepted: 06/30/2020] [Indexed: 05/06/2023]
Abstract
Raphidiopsis raciborskii is a widely distributed, potentially toxic cyanobacterium described as a tropical-subtropical species. However, its occurrence in temperate regions has been expanding. Understanding the environmental factors underlying the expansion and colonization success of Raphidiopsis has been the object of numerous studies. However, less is known regarding its responses to pH and inorganic carbon in water. Thus, the aim of the present study was to investigate the effects of changes in pH and dissolved inorganic carbon on growth and saxitoxins production in the strain R. raciborskii ITEP-A1. We incubated batch cultures with different unbuffered and buffered pH (neutral-acid and alkaline) and inorganic carbon availability (CO2-rich air bubbling and the addition of NaHCO3) to assess the effect of these factors on the growth, toxin production as well as saxitoxins composition of the cyanobacterium. The carbon concentrating mechanism (CCM) system of ITEP-A1 was also characterized by an in silico analysis of its previously sequenced genome. The growth and saxitoxins production of R. raciborskii were affected. The addition of sodium bicarbonate and air bubbling enhanced the growth of the cyanobacterium in alkaline pH. In contrast, saxitoxins production and relative toxicity were decreased. Moreover, significant changes in the cellular composition of saxitoxins were strongly related to pH changes. ITEP-A1 potentially expresses the low-flux bicarbonate transporter BicA, an efficient CCM which uptakes most of its carbon from HCO3-. Hence, increasing the diffusion of CO2 in alkaline eutrophic lakes is likely to increase R. raciborskii dominance, but produce less toxic blooms.
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Affiliation(s)
- Mauro Cesar Palmeira Vilar
- Graduate Program in Ecology, Biology Department, Rural Federal University of Pernambuco, Recife, PE, Brazil
| | - Renato José Reis Molica
- Academic Unit of Garanhuns, Rural Federal University of Pernambuco, Bom Pastor Avenue, Garanhuns, PE, 55292-270, Brazil.
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Vico P, Bonilla S, Cremella B, Aubriot L, Iriarte A, Piccini C. Biogeography of the cyanobacterium Raphidiopsis (Cylindrospermopsis) raciborskii: Integrating genomics, phylogenetic and toxicity data. Mol Phylogenet Evol 2020; 148:106824. [PMID: 32294544 DOI: 10.1016/j.ympev.2020.106824] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 02/07/2020] [Accepted: 04/07/2020] [Indexed: 12/18/2022]
Abstract
Raphidiopsis (Cylindrospermopsis) raciborskii, a globally distributed bloom-forming cyanobacterium, produces either the cytotoxin cylindrospermopsin (CYL) in Oceania, Asia and Europe or the neurotoxin saxitoxin (STX) and analogues (paralytic shellfish poison, PSP) in South America (encoded by sxt genetic cluster) and none of them in Africa. Nevertheless, this particular geographic pattern is usually overlooked in current hypotheses about the species dispersal routes. Here, we combined genomics, phylogenetic analyses, toxicity data and a literature survey to unveil the evolutionary history and spread of the species. Phylogenies based on 354 orthologous genes from all the available genomes and ribosomal ITS sequences of the taxon showed two well-defined clades: the American, having the PSP producers; and the Oceania/Europe/Asia, including the CYL producers. We propose central Africa as the original dispersion center (non-toxic populations), reaching North Africa and North America (in former Laurasia continent). The ability to produce CYL probably took place in populations that advanced to sub-Saharan Africa and then to Oceania and South America. According to the genomic context of the sxt cluster found in PSP-producer strains, this trait was acquired once by horizontal transfer in South America, where the ability to produce CYL was lost.
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Affiliation(s)
- Paula Vico
- Departamento de Microbiología, Instituto de Investigaciones Biológicas Clemente Estable, Avenida Italia 3318, 11600 Montevideo, Uruguay; Laboratorio de Biología Computacional, Departamento de Desarrollo Biotecnológico, Instituto de Higiene, Facultad de Medicina, Avenida A. Navarro 3051, 11600 Montevideo, Uruguay
| | - Sylvia Bonilla
- Sección Limnología, Instituto de Ecología y Ciencias Ambientales. Facultad de Ciencias. Universidad de la República, Iguá 4225, 11400 Montevideo, Uruguay; Physiology and Ecology Phytoplankton Group, CSIC, Uruguay
| | - Bruno Cremella
- Sección Limnología, Instituto de Ecología y Ciencias Ambientales. Facultad de Ciencias. Universidad de la República, Iguá 4225, 11400 Montevideo, Uruguay; Physiology and Ecology Phytoplankton Group, CSIC, Uruguay; Laboratory of Environmental Analysis, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Luis Aubriot
- Sección Limnología, Instituto de Ecología y Ciencias Ambientales. Facultad de Ciencias. Universidad de la República, Iguá 4225, 11400 Montevideo, Uruguay; Physiology and Ecology Phytoplankton Group, CSIC, Uruguay
| | - Andrés Iriarte
- Laboratorio de Biología Computacional, Departamento de Desarrollo Biotecnológico, Instituto de Higiene, Facultad de Medicina, Avenida A. Navarro 3051, 11600 Montevideo, Uruguay.
| | - Claudia Piccini
- Departamento de Microbiología, Instituto de Investigaciones Biológicas Clemente Estable, Avenida Italia 3318, 11600 Montevideo, Uruguay.
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Gracia Villalobos LL, Tobke JL, Montoya NG, Santinelli NH, Gil MN. Experimental exposure of the mussel Mytilus platensis (d'Orbigny, 1842) to the dinoflagellate Alexandrium catenella from Argentine Patagonia. ECOTOXICOLOGY (LONDON, ENGLAND) 2020; 29:226-235. [PMID: 32026312 DOI: 10.1007/s10646-020-02169-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/21/2020] [Indexed: 06/10/2023]
Abstract
Individuals of Mytilus platensis were exposed to Alexandrium catenella to evaluate the accumulation and metabolization of paralytic shellfish toxins (PST) over a period of 25 days. Mussels were collected from the intertidal zone of Cerro Avanzado, Argentine Patagonia. After 16 days, the toxins in the tissues of mussels were detected by the methods of mouse bioassay and high performance liquid chromatography with fluorometric detection (HPLC-FDL). The accumulation kinetics of PST toxins in M. platensis fed with A. catenella fitted to a linear function, in which the accumulation rate was 31.2 µg STX eq kg-1 day-1. After 16 days, the PST toxin level in tissues of mussels reached 1178 µg STX eq kg-1 exceeding the safety limit for human consumption (800 µg STX eq kg-1 tissue), whereas the highest PST toxin level was reached at the end of the experimentation (1613 µg STX eq kg-1) at 25 days. Differences in the toxin profile of the dinoflagellates and the tissues of the mussels confirmed biotransformation of PST in the mussel digestive system. The toxin profile of M. platensis was dominated by the gonyautoxins GTX1 and GTX4, while the toxin profile of A. catenella was dominated by the N-sulfocarbamoyl toxin C2. To our knowledge, this is the first experimentation on a laboratory scale of PST toxins accumulation in M. platensis with a native strain of A. catenella of Argentine Patagonia.
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Affiliation(s)
- Leilén L Gracia Villalobos
- Centro para el Estudio de Sistemas Marinos (CESIMAR)-CONICET, Boulevard Brown 2915, U9120ACD, Puerto Madryn, Argentina.
| | - Jésica L Tobke
- Centro para el Estudio de Sistemas Marinos (CESIMAR)-CONICET, Boulevard Brown 2915, U9120ACD, Puerto Madryn, Argentina
| | - Nora G Montoya
- Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), Paseo Victoria Ocampo N°1, Escollera Norte, B7602HSA, Mar del Plata, Argentina
| | - Norma H Santinelli
- Instituto de Investigación de Hidrobiología, Facultad de Ciencias Naturales y Ciencias de la Salud, Universidad Nacional de la Patagonia San Juan Bosco, Gales 48, U9100CKN, Trelew, Argentina
| | - Mónica N Gil
- Centro para el Estudio de Sistemas Marinos (CESIMAR)-CONICET, Boulevard Brown 2915, U9120ACD, Puerto Madryn, Argentina
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Di Dato V, Ianora A, Romano G. Identification of Prostaglandin Pathway in Dinoflagellates by Transcriptome Data Mining. Mar Drugs 2020; 18:md18020109. [PMID: 32069885 PMCID: PMC7073720 DOI: 10.3390/md18020109] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 02/07/2020] [Accepted: 02/11/2020] [Indexed: 12/28/2022] Open
Abstract
Dinoflagellates, a major class of marine eukaryote microalgae composing the phytoplankton, are widely recognised as producers of a large variety of toxic molecules, particularly neurotoxins, which can also act as potent bioactive pharmacological mediators. In addition, similarly to other microalgae, they are also good producers of polyunsaturated fatty acids (PUFAs), important precursors of key molecules involved in cell physiology. Among PUFA derivatives are the prostaglandins (Pgs), important physiological mediators in several physiological and pathological processes in humans, also used as “biological” drugs. Their synthesis is very expensive because of the elevated number of reaction steps required, thus the search for new Pgs production methods is of great relevance. One possibility is their extraction from microorganisms (e.g., diatoms), which have been proved to produce the same Pgs as humans. In the present study, we took advantage of the available transcriptomes for dinoflagellates in the iMicrobe database to search for the Pgs biosynthetic pathway using a bioinformatic approach. Here we show that dinoflagellates express nine Pg-metabolism related enzymes involved in both Pgs synthesis and reduction. Not all of the enzymes were expressed simultaneously in all the species analysed and their expression was influenced by culturing conditions, especially salinity of the growth medium. These results confirm the existence of a biosynthetic pathway for these important molecules in unicellular microalgae other than diatoms, suggesting a broad diffusion and conservation of the Pgs pathway, which further strengthen their importance in living organisms.
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Akbar MA, Mohd Yusof NY, Tahir NI, Ahmad A, Usup G, Sahrani FK, Bunawan H. Biosynthesis of Saxitoxin in Marine Dinoflagellates: An Omics Perspective. Mar Drugs 2020; 18:md18020103. [PMID: 32033403 PMCID: PMC7073992 DOI: 10.3390/md18020103] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 01/09/2020] [Accepted: 01/09/2020] [Indexed: 02/07/2023] Open
Abstract
Saxitoxin is an alkaloid neurotoxin originally isolated from the clam Saxidomus giganteus in 1957. This group of neurotoxins is produced by several species of freshwater cyanobacteria and marine dinoflagellates. The saxitoxin biosynthesis pathway was described for the first time in the 1980s and, since then, it was studied in more than seven cyanobacterial genera, comprising 26 genes that form a cluster ranging from 25.7 kb to 35 kb in sequence length. Due to the complexity of the genomic landscape, saxitoxin biosynthesis in dinoflagellates remains unknown. In order to reveal and understand the dynamics of the activity in such impressive unicellular organisms with a complex genome, a strategy that can carefully engage them in a systems view is necessary. Advances in omics technology (the collective tools of biological sciences) facilitated high-throughput studies of the genome, transcriptome, proteome, and metabolome of dinoflagellates. The omics approach was utilized to address saxitoxin-producing dinoflagellates in response to environmental stresses to improve understanding of dinoflagellates gene–environment interactions. Therefore, in this review, the progress in understanding dinoflagellate saxitoxin biosynthesis using an omics approach is emphasized. Further potential applications of metabolomics and genomics to unravel novel insights into saxitoxin biosynthesis in dinoflagellates are also reviewed.
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Affiliation(s)
- Muhamad Afiq Akbar
- School of Bioscience and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia;
| | - Nurul Yuziana Mohd Yusof
- Department of Earth Science and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia; (N.Y.M.Y.); (F.K.S.)
| | - Noor Idayu Tahir
- Malaysian Palm Oil Board, No 6, Persiaran Institusi, Bandar Baru Bangi, Kajang 43000, Selangor, Malaysia;
| | - Asmat Ahmad
- University College Sabah Foundation, Jalan Sanzac, Kota Kinabalu 88100, Sabah, Malaysia; (A.A.); (G.U.)
| | - Gires Usup
- University College Sabah Foundation, Jalan Sanzac, Kota Kinabalu 88100, Sabah, Malaysia; (A.A.); (G.U.)
| | - Fathul Karim Sahrani
- Department of Earth Science and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia; (N.Y.M.Y.); (F.K.S.)
| | - Hamidun Bunawan
- Institute of Systems Biology, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia
- Correspondence: ; Tel.: +60-389-214-546
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Ganley JG, Derbyshire ER. Linking Genes to Molecules in Eukaryotic Sources: An Endeavor to Expand Our Biosynthetic Repertoire. Molecules 2020; 25:E625. [PMID: 32023950 PMCID: PMC7036892 DOI: 10.3390/molecules25030625] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 01/23/2020] [Accepted: 01/30/2020] [Indexed: 02/06/2023] Open
Abstract
The discovery of natural products continues to interest chemists and biologists for their utility in medicine as well as facilitating our understanding of signaling, pathogenesis, and evolution. Despite an attenuation in the discovery rate of new molecules, the current genomics and transcriptomics revolution has illuminated the untapped biosynthetic potential of many diverse organisms. Today, natural product discovery can be driven by biosynthetic gene cluster (BGC) analysis, which is capable of predicting enzymes that catalyze novel reactions and organisms that synthesize new chemical structures. This approach has been particularly effective in mining bacterial and fungal genomes where it has facilitated the discovery of new molecules, increased the understanding of metabolite assembly, and in some instances uncovered enzymes with intriguing synthetic utility. While relatively less is known about the biosynthetic potential of non-fungal eukaryotes, there is compelling evidence to suggest many encode biosynthetic enzymes that produce molecules with unique bioactivities. In this review, we highlight how the advances in genomics and transcriptomics have aided natural product discovery in sources from eukaryotic lineages. We summarize work that has successfully connected genes to previously identified molecules and how advancing these techniques can lead to genetics-guided discovery of novel chemical structures and reactions distributed throughout the tree of life. Ultimately, we discuss the advantage of increasing the known biosynthetic space to ease access to complex natural and non-natural small molecules.
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Affiliation(s)
- Jack G Ganley
- Department of Chemistry, Duke University, 124 Science Drive, Durham, NC 27708-0346, USA
| | - Emily R Derbyshire
- Department of Chemistry, Duke University, 124 Science Drive, Durham, NC 27708-0346, USA
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, 213 Research Drive, Durham, NC 27710, USA
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Hu Y, Wang L, Shao D, Wang Q, Wu Y, Han Y, Shi S. Selectived and Reshaped Early Dominant Microbial Community in the Cecum With Similar Proportions and Better Homogenization and Species Diversity Due to Organic Acids as AGP Alternatives Mediate Their Effects on Broilers Growth. Front Microbiol 2020; 10:2948. [PMID: 31993028 PMCID: PMC6971172 DOI: 10.3389/fmicb.2019.02948] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 12/06/2019] [Indexed: 01/16/2023] Open
Abstract
Understanding the differences in microbial communities shaped by different food selective forces, especially during early post-hatch period, is critical to gain insight into how to select, evaluate, and improve antibiotic growth promoters (AGPs) alternatives in food animals. As a model system, commercial diet-administered OAs (DOAs) and water-administered OAs (WOAs) were used separately or in combination as Virginiamycin alternatives for broiler feeding during two growth phases: 1–21 days and 22–42 days. Among these three OA-treated groups, the DOA group was most similar to the AGP group in the composition and the proportion of these dominant bacterial communities at the level of phylum, family, and genus in cecal chyme of broilers. Sub-therapeutic Virginiamycin decreased the richness, homogenization, and species diversity of gut microbiota, especially in the early growth stage from days 1 to 21. Among these three OA supplementation schemes, it was clear that DOA supplementation was more likely to increase or maintain the richness, homogenization, species diversity, and predicted gene functions of cecal microbiota in treated broilers than either no supplementation or AGP supplementation during two experimental stages. The interference of DOA treatment with early colonization of probiotics and pathogens in broiler cecum was the most similar to AGP treatment, and OAs did not cause the occurrence of Virginiamycin-resistant strains of Enterococcus at the end of this trial. In terms of the predicted gene functions of the microbiota, AGP and DOA treatments provided a similar selective force for microbial metabolism functions in the cecum of broiler chickens, especially in the early growth stage. Noticeably, the relative abundance of some microbiome that was modified by Virginiamycin or DOA supplementation was significantly correlated with body weight gain and KEGG pathway analysis-annotated gene functions such as replication and repair, translation, nucleotide metabolism, and so on. With the comprehensive analysis of these results and practical application, shortened DOA supplementation, after optimization of the amount of addition, would be a suitable alternative to sub-therapeutic Virginiamycin. It was suggested that the programed intestinal microecology under such early selection forces and the effective addition time may be the key elements to focus on the designed alternate strategies of AGPs in food animals.
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Affiliation(s)
- Yan Hu
- Poultry Institute, Chinese Academy of Agriculture Sciences, Yangzhou, China.,Center of Effective Evaluation of Feed and Feed Additive, Poultry Institute, Ministry of Agriculture, Yangzhou, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Laidi Wang
- Poultry Institute, Chinese Academy of Agriculture Sciences, Yangzhou, China.,Center of Effective Evaluation of Feed and Feed Additive, Poultry Institute, Ministry of Agriculture, Yangzhou, China
| | - Dan Shao
- Poultry Institute, Chinese Academy of Agriculture Sciences, Yangzhou, China.,Center of Effective Evaluation of Feed and Feed Additive, Poultry Institute, Ministry of Agriculture, Yangzhou, China
| | - Qiang Wang
- Poultry Institute, Chinese Academy of Agriculture Sciences, Yangzhou, China.,Center of Effective Evaluation of Feed and Feed Additive, Poultry Institute, Ministry of Agriculture, Yangzhou, China
| | - Yuanyuan Wu
- Trouw Nutrition R&D, Amersfoort, Netherlands
| | - Yanming Han
- Trouw Nutrition R&D, Amersfoort, Netherlands
| | - Shourong Shi
- Poultry Institute, Chinese Academy of Agriculture Sciences, Yangzhou, China.,Center of Effective Evaluation of Feed and Feed Additive, Poultry Institute, Ministry of Agriculture, Yangzhou, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
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Verma A, Barua A, Ruvindy R, Savela H, Ajani PA, Murray SA. The Genetic Basis of Toxin Biosynthesis in Dinoflagellates. Microorganisms 2019; 7:E222. [PMID: 31362398 PMCID: PMC6722697 DOI: 10.3390/microorganisms7080222] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 07/23/2019] [Accepted: 07/27/2019] [Indexed: 02/07/2023] Open
Abstract
In marine ecosystems, dinoflagellates can become highly abundant and even dominant at times, despite their comparatively slow growth rates. One factor that may play a role in their ecological success is the production of complex secondary metabolite compounds that can have anti-predator, allelopathic, or other toxic effects on marine organisms, and also cause seafood poisoning in humans. Our knowledge about the genes involved in toxin biosynthesis in dinoflagellates is currently limited due to the complex genomic features of these organisms. Most recently, the sequencing of dinoflagellate transcriptomes has provided us with valuable insights into the biosynthesis of polyketide and alkaloid-based toxin molecules in dinoflagellate species. This review synthesizes the recent progress that has been made in understanding the evolution, biosynthetic pathways, and gene regulation in dinoflagellates with the aid of transcriptomic and other molecular genetic tools, and provides a pathway for future studies of dinoflagellates in this exciting omics era.
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Affiliation(s)
- Arjun Verma
- Climate Change Cluster, University of Technology Sydney, Sydney 2007, Australia.
| | - Abanti Barua
- Climate Change Cluster, University of Technology Sydney, Sydney 2007, Australia
- Department of Microbiology, Noakhali Science and Technology University, Chittagong 3814, Bangladesh
| | - Rendy Ruvindy
- Climate Change Cluster, University of Technology Sydney, Sydney 2007, Australia
| | - Henna Savela
- Finnish Environment Institute, Marine Research Centre, 00790 Helsinki, Finland
| | - Penelope A Ajani
- Climate Change Cluster, University of Technology Sydney, Sydney 2007, Australia
| | - Shauna A Murray
- Climate Change Cluster, University of Technology Sydney, Sydney 2007, Australia
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Barros MUG, Wilson AE, Leitão JIR, Pereira SP, Buley RP, Fernandez-Figueroa EG, Capelo-Neto J. Environmental factors associated with toxic cyanobacterial blooms across 20 drinking water reservoirs in a semi-arid region of Brazil. HARMFUL ALGAE 2019; 86:128-137. [PMID: 31358272 DOI: 10.1016/j.hal.2019.05.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 05/07/2019] [Accepted: 05/08/2019] [Indexed: 06/10/2023]
Abstract
Cyanobacteria are known to produce a wide variety of bioactive, toxic secondary metabolites generally described as hepatotoxins, neurotoxins, cytotoxins, or dermatoxins. In Brazil, the regular monitoring of cyanobacterial toxins has intensified after the death of 65 patients in a hemodialysis clinic in Caruaru in the state of Pernambuco due to microcystin exposure. The primary objective of this study was to use multivariate statistics that incorporated environmental parameters (both biotic and abiotic) to forecast blooms of cyanobacteria and their toxic secondary metabolites in 20 drinking water reservoirs managed by the Water Treatment Company of Ceará (CAGECE) in the semi-arid region of Ceará, Brazil. Across four years (January 2013 to January 2017), 114 different phytoplankton taxa were identified, including 24 cyanobacterial taxa. In general, Ceará reservoirs were dominated by cyanobacteria due to eutrophication but also because of the dry and warm climate found throughout the region. Interestingly, specific cyanobacterial taxa were influenced by different biotic and abiotic factors. For example, nitrogen-to-phosphorus (N:P) and evaporation were positively related to saxitoxin-producing taxa, especially Raphidiopsis raciborskii, while temperature, electrical conductivity, total phosphorus, and transparency (measured as Secchi depth) were positively associated with microcystin-producing taxa, such as Microcystis aeruginosa. Climate forecasts predict higher evaporation and temperatures in the semi-arid Ceará region, which will likely magnify droughts and water scarcity as well as promote toxic cyanobacterial blooms in reservoirs in the future. Therefore, understanding the factors associated with algal blooms dominated by specific taxa is paramount for water resource management.
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Affiliation(s)
- Mário U G Barros
- Federal University of Ceará, Department of Hydraulic and Environmental Engineering, Block 713, Campus Pici, Fortaleza, Ceará, Brazil; Auburn University, School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn, Alabama, 36849, USA
| | - Alan E Wilson
- Auburn University, School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn, Alabama, 36849, USA.
| | - João I R Leitão
- Federal University of Ceará, Department of Hydraulic and Environmental Engineering, Block 713, Campus Pici, Fortaleza, Ceará, Brazil
| | - Silvano P Pereira
- Water Treatment Company of Ceará, CAGECE, 1030, Lauro Vieira Chaves Av, Fortaleza, Ceará, Brazil
| | - Riley P Buley
- Auburn University, School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn, Alabama, 36849, USA
| | - Edna G Fernandez-Figueroa
- Auburn University, School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn, Alabama, 36849, USA
| | - José Capelo-Neto
- Federal University of Ceará, Department of Hydraulic and Environmental Engineering, Block 713, Campus Pici, Fortaleza, Ceará, Brazil
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Lukowski AL, Narayan ARH. Natural Voltage-Gated Sodium Channel Ligands: Biosynthesis and Biology. Chembiochem 2019; 20:1231-1241. [PMID: 30605564 PMCID: PMC6579537 DOI: 10.1002/cbic.201800754] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Indexed: 12/18/2022]
Abstract
Natural product biosynthetic pathways are composed of enzymes that use powerful chemistry to assemble complex molecules. Small molecule neurotoxins are examples of natural products with intricate scaffolds which often have high affinities for their biological targets. The focus of this Minireview is small molecule neurotoxins targeting voltage-gated sodium channels (VGSCs) and the state of knowledge on their associated biosynthetic pathways. There are three small molecule neurotoxin receptor sites on VGSCs associated with three different classes of molecules: guanidinium toxins, alkaloid toxins, and ladder polyethers. Each of these types of toxins have unique structural features which are assembled by biosynthetic enzymes and the extent of information known about these enzymes varies among each class. The biosynthetic enzymes involved in the formation of these toxins have the potential to become useful tools in the efficient synthesis of VGSC probes.
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Affiliation(s)
- April L Lukowski
- Program in Chemical Biology, University of Michigan, 210 Washtenaw Ave., Ann Arbor, MI, 48109, USA
| | - Alison R H Narayan
- Life Sciences Institute, University of Michigan, 210 Washtenaw Ave., Ann Arbor, MI, 48109, USA
- Department of Chemistry, University of Michigan, 930 N University Ave., Ann Arbor, MI, 48109, USA
- Program in Chemical Biology, University of Michigan, 210 Washtenaw Ave., Ann Arbor, MI, 48109, USA
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42
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Tóth Z, Kurali A, Móricz ÁM, Hettyey A. Changes in Toxin Quantities Following Experimental Manipulation of Toxin Reserves in Bufo bufo Tadpoles. J Chem Ecol 2019; 45:253-263. [PMID: 30684072 PMCID: PMC6477007 DOI: 10.1007/s10886-019-01045-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 10/25/2018] [Accepted: 01/06/2019] [Indexed: 01/08/2023]
Abstract
Possessing toxins can contribute to an efficient defence against various threats in nature. However, we generally know little about the energy- and time-demands of developing toxicity in animals, which determines the efficiency of chemical defence and its trade-off with other risk-induced phenotypic responses. In this study we examined how immersion into norepinephrine solution inducing the release of stored toxins, administration of mild stress mimicking predator attack or simple handling during experimental procedure affected the quantity and number of toxin compounds present in common toad (Bufo bufo) tadpoles as compared to undisturbed control individuals, and investigated how fast toxin reserves were restored. We found that total bufadienolide quantity (TBQ) significantly decreased only in the norepinephrine treatment group immediately after treatment compared to the control, but this difference disappeared after 12 h; there were no consistent differences in TBQ between treatments at later samplings. Interestingly, in the norepinephrine treatment approximately half of the compounds characterized by >700 m/z values showed the same changes in time as TBQ, but several bufadienolides characterized by <600 m/z values showed the opposite pattern: they were present in higher quantities immediately after treatment. The number of bufadienolide compounds was not affected by any treatments, but was positively related to TBQ. Our study represents the first experimental evidence that toxin quantities returned to the original level following induced toxin release within a very short period of time in common toad tadpoles and provide additional insights into the physiological background of chemical defence in this model vertebrate species.
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Affiliation(s)
- Zoltán Tóth
- Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó Str. 15, Budapest, H-1022, Hungary.
| | - Anikó Kurali
- Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó Str. 15, Budapest, H-1022, Hungary
| | - Ágnes M Móricz
- Department of Pathophysiology, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó Str. 15, Budapest, H-1022, Hungary
| | - Attila Hettyey
- Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó Str. 15, Budapest, H-1022, Hungary
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D'Agostino PM, Boundy MJ, Harwood TD, Carmichael WW, Neilan BA, Wood SA. Re-evaluation of paralytic shellfish toxin profiles in cyanobacteria using hydrophilic interaction liquid chromatography-tandem mass spectrometry. Toxicon 2019; 158:1-7. [DOI: 10.1016/j.toxicon.2018.11.301] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 10/12/2018] [Accepted: 11/18/2018] [Indexed: 10/27/2022]
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iTRAQ-Based Quantitative Proteomic Analysis of a Toxigenic Dinoflagellate Alexandrium catenella at Different Stages of Toxin Biosynthesis during the Cell Cycle. Mar Drugs 2018; 16:md16120491. [PMID: 30544585 PMCID: PMC6315610 DOI: 10.3390/md16120491] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 12/02/2018] [Accepted: 12/04/2018] [Indexed: 01/15/2023] Open
Abstract
Paralytic shellfish toxins (PSTs) are a group of potent neurotoxic alkaloids that are produced mainly by marine dinoflagellates. PST biosynthesis in dinoflagellates is a discontinuous process that is coupled to the cell cycle. However, little is known about the molecular mechanism underlying this association. Here, we compared global protein expression profiles of a toxigenic dinoflagellate, Alexandrium catenella, collected at four different stages of toxin biosynthesis during the cell cycle, using an isobaric tags for relative and absolute quantification (iTRAQ)-based quantitative proteomic approach. The results showed that toxin biosynthesis occurred mainly in the G1 phase, especially the late G1 phase. In total, 7232 proteins were confidently identified, and 210 proteins exhibited differential expression among the four stages. Proteins involved in protein translation and photosynthetic pigment biosynthesis were significantly upregulated during toxin biosynthesis, indicating close associations among the three processes. Nine toxin-related proteins were detected, and two core toxin biosynthesis proteins, namely, sxtA and sxtI, were identified for the first time in dinoflagellates. Among these proteins, sxtI and ompR were significantly downregulated when toxin biosynthesis stopped, indicating that they played important roles in the regulation of PST biosynthesis. Our study provides new insights into toxin biosynthesis in marine dinoflagellates: nitrogen balance among different biological processes regulates toxin biosynthesis, and that glutamate might play a key modulatory role.
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Petkowski JJ, Bains W, Seager S. Natural Products Containing a Nitrogen-Sulfur Bond. JOURNAL OF NATURAL PRODUCTS 2018; 81:423-446. [PMID: 29364663 DOI: 10.1021/acs.jnatprod.7b00921] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Only about 100 natural products are known to contain a nitrogen-sulfur (N-S) bond. This review thoroughly categorizes N-S bond-containing compounds by structural class. Information on biological source, biological activity, and biosynthesis is included, if known. We also review the role of N-S bond functional groups as post-translational modifications of amino acids in proteins and peptides, emphasizing their role in the metabolism of the cell.
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Affiliation(s)
- Janusz J Petkowski
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - William Bains
- Rufus Scientific , 37 The Moor, Melbourn, Royston, Herts SG8 6ED, U.K
| | - Sara Seager
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Department of Physics, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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46
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Fast and quantitative determination of saxitoxin and neosaxitoxin in urine by ultra performance liquid chromatography-triple quadrupole mass spectrometry based on the cleanup of solid phase extraction with hydrophilic interaction mechanism. J Chromatogr B Analyt Technol Biomed Life Sci 2018; 1072:267-272. [DOI: 10.1016/j.jchromb.2017.11.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 11/22/2017] [Accepted: 11/24/2017] [Indexed: 02/07/2023]
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García PA, Valles E, Díez D, Castro MÁ. Marine Alkylpurines: A Promising Group of Bioactive Marine Natural Products. Mar Drugs 2018; 16:md16010006. [PMID: 29301246 PMCID: PMC5793054 DOI: 10.3390/md16010006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 12/16/2017] [Accepted: 12/19/2017] [Indexed: 11/16/2022] Open
Abstract
Marine secondary metabolites with a purine motif in their structure are presented in this review. The alkylpurines are grouped according to the size of the alkyl substituents and their location on the purine ring. Aspects related to the marine source, chemical structure and biological properties are considered together with synthetic approaches towards the natural products and bioactive analogues. This review contributes to studies of structure–activity relationships for these metabolites and highlights the potential of the sea as a source of new lead compounds in diverse therapeutic fields.
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Affiliation(s)
- Pablo A García
- Department of Pharmaceutical Sciences, Medicinal Chemistry Section, Pharmacy Faculty, CIETUS, IBSAL, University of Salamanca, E-37007 Salamanca, Spain.
| | - Elena Valles
- Department of Pharmaceutical Sciences, Medicinal Chemistry Section, Pharmacy Faculty, CIETUS, IBSAL, University of Salamanca, E-37007 Salamanca, Spain.
| | - David Díez
- Department of Organic Chemistry, Faculty of Chemical Sciences, University of Salamanca, E-37008 Salamanca, Spain.
| | - María-Ángeles Castro
- Department of Pharmaceutical Sciences, Medicinal Chemistry Section, Pharmacy Faculty, CIETUS, IBSAL, University of Salamanca, E-37007 Salamanca, Spain.
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Assunção J, Guedes AC, Malcata FX. Biotechnological and Pharmacological Applications of Biotoxins and Other Bioactive Molecules from Dinoflagellates. Mar Drugs 2017; 15:E393. [PMID: 29261163 PMCID: PMC5742853 DOI: 10.3390/md15120393] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 12/12/2017] [Accepted: 12/15/2017] [Indexed: 12/26/2022] Open
Abstract
The long-lasting interest in bioactive molecules (namely toxins) produced by (microalga) dinoflagellates has risen in recent years. Exhibiting wide diversity and complexity, said compounds are well-recognized for their biological features, with great potential for use as pharmaceutical therapies and biological research probes. Unfortunately, provision of those compounds is still far from sufficient, especially in view of an increasing demand for preclinical testing. Despite the difficulties to establish dinoflagellate cultures and obtain reasonable productivities of such compounds, intensive research has permitted a number of advances in the field. This paper accordingly reviews the characteristics of some of the most important biotoxins (and other bioactive substances) produced by dinoflagellates. It also presents and discusses (to some length) the main advances pertaining to dinoflagellate production, from bench to large scale-with an emphasis on material published since the latest review available on the subject. Such advances encompass improvements in nutrient formulation and light supply as major operational conditions; they have permitted adaptation of classical designs, and aided the development of novel configurations for dinoflagellate growth-even though shearing-related issues remain a major challenge.
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Affiliation(s)
- Joana Assunção
- LEPABE-Laboratory of Process Engineering, Environment, Biotechnology and Energy, Rua Dr. Roberto Frias, s/n, P-4200-465 Porto, Portugal.
| | - A Catarina Guedes
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, s/n, P-4450-208 Matosinhos, Portugal.
| | - F Xavier Malcata
- LEPABE-Laboratory of Process Engineering, Environment, Biotechnology and Energy, Rua Dr. Roberto Frias, s/n, P-4200-465 Porto, Portugal.
- Department of Chemical Engineering, University of Porto, Rua Dr. Roberto Frias, s/n, P-4200-465 Porto, Portugal.
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Lian Z, Wang J. Selective isolation of gonyautoxins 1,4 from the dinoflagellate Alexandrium minutum based on molecularly imprinted solid-phase extraction. MARINE POLLUTION BULLETIN 2017; 122:500-504. [PMID: 28662976 DOI: 10.1016/j.marpolbul.2017.06.066] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 06/20/2017] [Accepted: 06/21/2017] [Indexed: 06/07/2023]
Abstract
Gonyautoxins 1,4 (GTX1,4) from Alexandrium minutum samples were isolated selectively and recognized specifically by an innovative and effective extraction procedure based on molecular imprinting technology. Novel molecularly imprinted polymer microspheres (MIPMs) were prepared by double-templated imprinting strategy using caffeine and pentoxifylline as dummy templates. The synthesized polymers displayed good affinity to GTX1,4 and were applied as sorbents. Further, an off-line molecularly imprinted solid-phase extraction (MISPE) protocol was optimized and an effective approach based on the MISPE coupled with HPLC-FLD was developed for selective isolation of GTX1,4 from the cultured A. minutum samples. The separation method showed good extraction efficiency (73.2-81.5%) for GTX1,4 and efficient removal of interferences matrices was also achieved after the MISPE process for the microalgal samples. The outcome demonstrated the superiority and great potential of the MISPE procedure for direct separation of GTX1,4 from marine microalgal extracts.
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Affiliation(s)
- Ziru Lian
- Marine College, Shandong University, Weihai 264209, China
| | - Jiangtao Wang
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100,China.
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Ding L, Qiu J, Li A. Proposed Biotransformation Pathways for New Metabolites of Paralytic Shellfish Toxins Based on Field and Experimental Mussel Samples. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:5494-5502. [PMID: 28616979 DOI: 10.1021/acs.jafc.7b02101] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A seafood poisoning event occurred in Qinhuangdao, China, in April 2016. Subsequently, the causative mussels (Mytilus galloprovincialis) were harvested and analyzed to reveal a high concentration [∼10 758 μg of saxitoxin (STX) equiv kg-1] of paralytic shellfish toxins (PSTs), including gonyautoxin (GTX)1/4 and GTX2/3, as well as new metabolites 11-hydroxy-STX (M2), 11,11-dihydroxy-STX (M4), open-ring 11,11-dihydroxy-STX (M6), 11-hydroxy-neosaxitoxin (NEO) (M8), and 11,11-dihydroxy-NEO (M10). To understand the origin and biotransformation pathways of these new metabolites, uncontaminated mussels (M. galloprovincialis) were fed with either of two Alexandrium tamarense strains (ATHK and TIO108) under laboratory conditions. Similar PST metabolites were also detected in mussels from both feeding experiments. Results supposed that 11-hydroxy-C2 toxin (M1) and 11,11-dihydroxy-C2 (M3) are transformed from C2, while 11-hydroxy-C4 toxin (M7) and 11,11-dihydroxy-C4 (M9) are converted from C4. In addition, the metabolites M2, M4, and M6 appear to be products of GTX2/3, and the metabolites M8 and M10 are likely derived from GTX1/4.
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Affiliation(s)
- Ling Ding
- College of Environmental Science and Engineering, Ocean University of China , Qingdao, Shandong 266100, People's Republic of China
| | - Jiangbing Qiu
- College of Environmental Science and Engineering, Ocean University of China , Qingdao, Shandong 266100, People's Republic of China
| | - Aifeng Li
- College of Environmental Science and Engineering, Ocean University of China , Qingdao, Shandong 266100, People's Republic of China
- Key Laboratory of Marine Environment and Ecology, Ocean University of China, Ministry of Education , Qingdao, Shandong 266100, People's Republic of China
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