1
|
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.
Collapse
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;
| |
Collapse
|
2
|
Pham ML, Askarzadmohassel E, Brandl M. Growth of freshwater cyanobacterium Aphanizomenon sp. ULC602 in different growing and nutrient conditions. Front Microbiol 2023; 14:1220818. [PMID: 38188574 PMCID: PMC10768055 DOI: 10.3389/fmicb.2023.1220818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 12/06/2023] [Indexed: 01/09/2024] Open
Abstract
Aphanizomenon sp. ULC602, recently isolated in a Belgian lake, is a filamentous, nitrogen-fixing, freshwater cyanobacterium that is one of the primary producers of cyanotoxins following its bloom formation, causing water contamination. This study aims to evaluate the effects of growing conditions and essential nutrients on the growth of Aphanizomenon sp. ULC602 via its production of chlorophyll-a (Chlo-a). Our results indicated that this bacterium could grow well at temperatures ranging from 18 to 25°C with an optimal pH of 6.0-7.5 under continuous lighting. It grew slowly in the absence of a carbon source or at lower carbon concentrations. The addition of nitrogen from nitrate and urea led to a less than 50% reduction of Chlo-a content compared to the medium lacking nitrogen. The iron bioavailability significantly stimulated the Chlo-a production, but it was saturated by an iron concentration of 0.115 mM. Moreover, a decrease in Chlo-a biomass was observed under sulfur deficiency. The bacterium could not grow well in media containing various phosphorus sources. In conclusion, as the growth and consequent forming bloom of cyanobacteria can be stimulated or inhibited by environmental conditions and eutrophication, our investigation could contribute to further studies to control the blooming of the target bacterium in freshwater.
Collapse
Affiliation(s)
- Mai-Lan Pham
- Center for Water and Environmental Sensors, Department for Integrated Sensor Systems, University for Continuing Education Krems, Krems an der Donau, Austria
| | | | | |
Collapse
|
3
|
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.
Collapse
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.
| |
Collapse
|
4
|
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.
Collapse
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.
| |
Collapse
|
5
|
Metz TT, Putnam SP, Scott GI, Ferry JL. Shoreline Drying of Microseira (Lyngbya) wollei Biomass Can Lead to the Release and Formation of Toxic Saxitoxin Analogues to the Water Column. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:16866-16872. [PMID: 36399599 DOI: 10.1021/acs.est.2c05579] [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] [Indexed: 06/16/2023]
Abstract
The harmful, filamentous cyanobacteria Microseira (Lyngbya) wollei produces several toxic analogues of saxitoxin (Lyngbya wollei toxins 1-6, or LWTs 1-6), grows in shallow water, and can deposit significant biomass on nearby shorelines. Here, we show that the LWTs are stable in the biomass during subsequent drying but that the process facilitates the later release of LWTs upon return to the water column. Under basic conditions, LWTs hydrolyzed to generate products that were significantly more neurotoxic than the initial toxins. Aqueous LWTs were subjected to conditions of covarying temperature and pH, and their degradation rates and products were determined at each condition. LWTs 1, 5, and 6 degraded faster at pH ≥ 8 at all temperatures. Their degradation products, which included decarbamoyl saxitoxin and LWT 4, were consistent with a base-catalyzed hydrolysis mechanism and represented a net increase in total biomass toxicity normalized against the equivalent toxicity of saxitoxin. The corresponding pre-exponential terms and activation energies for hydrolysis were obtained for pH 6-10 over the temperature range 10-40 °C. A locally weighted scatterplot smoothing (LOWESS) regression was developed to predict the loss of parent toxins and subsequent products in the water column under conditions corresponding to those commonly encountered in cyanobacterial blooms.
Collapse
Affiliation(s)
- Tryston T Metz
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, South Carolina29208, United States
- Center for Oceans and Human Health and Climate Change Interactions, University of South Carolina, Columbia, South Carolina29208, United States
| | - Samuel P Putnam
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, South Carolina29208, United States
- Center for Oceans and Human Health and Climate Change Interactions, University of South Carolina, Columbia, South Carolina29208, United States
| | - Geoffrey I Scott
- Center for Oceans and Human Health and Climate Change Interactions, University of South Carolina, Columbia, South Carolina29208, United States
- Department of Environmental Health Science, University of South Carolina, 921 Assembly Street, Columbia, South Carolina29208, United States
| | - John L Ferry
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, South Carolina29208, United States
- Center for Oceans and Human Health and Climate Change Interactions, University of South Carolina, Columbia, South Carolina29208, United States
| |
Collapse
|
6
|
Kramer BJ, Hem R, Gobler CJ. Elevated CO 2 significantly increases N 2 fixation, growth rates, and alters microcystin, anatoxin, and saxitoxin cell quotas in strains of the bloom-forming cyanobacteria, Dolichospermum. HARMFUL ALGAE 2022; 120:102354. [PMID: 36470609 DOI: 10.1016/j.hal.2022.102354] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 11/02/2022] [Accepted: 11/11/2022] [Indexed: 06/17/2023]
Abstract
The effect of rising CO2 levels on cyanobacterial harmful algal blooms (CHABs) is an emerging concern, particularly within eutrophic ecosystems. While elevated pCO2 has been associated with enhanced growth rates of some cyanobacteria, few studies have explored the effect of CO2 and nitrogen availability on diazotrophic (N2-fixing) cyanobacteria that produce cyanotoxins. Here, the effects of elevated CO2 and fixed nitrogen (NO3-) availability on the growth rates, toxin production, and N2 fixation of microcystin, saxitoxin, and anatoxin-a - producing strains of the genus Dolichospermum were quantified. Growth rates of all Dolichospermum spp. were significantly increased by CO2 or both CO2 and NO3- with rates being highest in treatments with the highest levels of CO2 and NO3-for all strains. While NO3- suppressed N2 fixation, diazotrophy significantly increased when NO3--enriched Dolichospermum spp. were supplied with higher CO2 compared to cultures grown under lower CO2 levels. This suggests that diazotrophy will play an increasingly important role in N cycling in CO2-enriched, eutrophic lentic systems. NO3- significantly increased quotas of the N-rich cyanotoxins, microcystin and saxitoxin, at ambient and enriched CO2 levels, respectively. In contrast, elevated CO2 significantly decreased cell quotas of microcystin and saxitoxin, but significantly increased cell quotas of the N-poor cyanotoxin, anatoxin. N2 fixation was significantly negatively and positively correlated with quotas of N-rich and N-poor cyanotoxins, respectively. Findings suggest cellular quotas of N-rich toxins (microcystin and saxitoxin) may be significantly reduced, or cellular quotas of N-poor toxins (anatoxin) may be significantly enhanced, under elevated CO2 conditions during diazotrophic cyanobacterial blooms. Finally, in the future, ecosystems that experience combinations of excessive N loading and CO2 enrichment may become more prone to toxic blooms of Dolichospermum.
Collapse
Affiliation(s)
- Benjamin J Kramer
- School of Marine and Atmospheric Sciences, Stony Brook University, 239 Montauk Highway, Southampton, NY, United States, 11968
| | - Ronojoy Hem
- School of Marine and Atmospheric Sciences, Stony Brook University, 239 Montauk Highway, Southampton, NY, United States, 11968
| | - Christopher J Gobler
- School of Marine and Atmospheric Sciences, Stony Brook University, 239 Montauk Highway, Southampton, NY, United States, 11968.
| |
Collapse
|
7
|
Wang H, Kim H, Park H, Ki JS. Temperature influences the content and biosynthesis gene expression of saxitoxins (STXs) in the toxigenic dinoflagellate Alexandrium pacificum. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 802:149801. [PMID: 34454155 DOI: 10.1016/j.scitotenv.2021.149801] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 08/16/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
Temperature may affect the production of saxitoxin (STX) and its derivatives (STXs); however, this is still controversial. Further, STX-biosynthesis gene regulation and the relation of its toxicity with temperature are not clearly understood. In the present study, we evaluated the effects of different temperatures (12 °C, 16 °C, and 20 °C) on the growth, toxin profiles, and expression of two core STX-biosynthesis genes, sxtA and sxtG, in the toxic dinoflagellate Alexandrium pacificum Alex05, isolated from Korean coasts. We found that temperature significantly affected cell growth, with maximum growth recorded at 16 °C, followed by 20 °C and 12 °C. HPLC analysis revealed mostly 12 of STXs from the tested cultures. Interestingly, the contents of STXs increased in the cells cultured at 16 °C and exposed to cold stress, compared to the 20 °C culture and heat stress; however, toxin components were much more diverse under heat stress. These toxin profiles generally matched with the sxtA and sxtG expression levels. Incubation at lower temperatures (12 °C and 16 °C) and exposure to cold stress increased sxtA and sxtG expressions in the cells, whereas heat stress showed little change or downregulated the transcription of both genes. Principal component analysis (PCA) showed low correlation between STXs eq and expressional levels of sxtA and sxtG in heat-stressed cells. These results suggest that temperature might be a crucial factor affecting the level and biosynthesis of STXs in marine toxic dinoflagellates.
Collapse
Affiliation(s)
- Hui Wang
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea; Hunan Key Laboratory of Typical Environmental Pollution and Health Hazards, School of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, China
| | - Hansol Kim
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea
| | - Hyunjun Park
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea
| | - Jang-Seu Ki
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea.
| |
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
Kim H, Park H, Wang H, Yoo HY, Park J, Ki JS. Low Temperature and Cold Stress Significantly Increase Saxitoxins (STXs) and Expression of STX Biosynthesis Genes sxtA4 and sxtG in the Dinoflagellate Alexandrium catenella. Mar Drugs 2021; 19:291. [PMID: 34064031 PMCID: PMC8224010 DOI: 10.3390/md19060291] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/18/2021] [Accepted: 05/18/2021] [Indexed: 12/22/2022] Open
Abstract
Toxic dinoflagellate Alexandrium spp. produce saxitoxins (STXs), whose biosynthesis pathway is affected by temperature. However, the link between the regulation of the relevant genes and STXs' accumulation and temperature is insufficiently understood. In the present study, we evaluated the effects of temperature on cellular STXs and the expression of two core STX biosynthesis genes (sxtA4 and sxtG) in the toxic dinoflagellate Alexandrium catenella Alex03 isolated from Korean waters. We analyzed the growth rate, toxin profiles, and gene responses in cells exposed to different temperatures, including long-term adaptation (12, 16, and 20 °C) and cold and heat stresses. Temperature significantly affected the growth of A. catenella, with optimal growth (0.49 division/day) at 16 °C and the largest cell size (30.5 µm) at 12 °C. High concentration of STXs eq were detected in cells cultured at 16 °C (86.3 fmol/cell) and exposed to cold stress at 20→12 °C (96.6 fmol/cell) compared to those at 20 °C and exposed to heat stress. Quantitative real-time PCR (qRT-PCR) revealed significant gene expression changes of sxtA4 in cells cultured at 16 °C (1.8-fold) and cold shock at 20→16 °C (9.9-fold). In addition, sxtG was significantly induced in cells exposed to cold shocks (20→16 °C; 19.5-fold) and heat stress (12→20 °C; 25.6-fold). Principal component analysis (PCA) revealed that low temperature (12 and 16 °C) and cold stress were positively related with STXs' production and gene expression levels. These results suggest that temperature may affect the toxicity and regulation of STX biosynthesis genes in dinoflagellates.
Collapse
Affiliation(s)
- Hansol Kim
- Department of Biotechnology, Sangmyung University, Seoul 03016, Korea; (H.K.); (H.P.); (H.W.); (H.Y.Y.)
| | - Hyunjun Park
- Department of Biotechnology, Sangmyung University, Seoul 03016, Korea; (H.K.); (H.P.); (H.W.); (H.Y.Y.)
| | - Hui Wang
- Department of Biotechnology, Sangmyung University, Seoul 03016, Korea; (H.K.); (H.P.); (H.W.); (H.Y.Y.)
| | - Hah Young Yoo
- Department of Biotechnology, Sangmyung University, Seoul 03016, Korea; (H.K.); (H.P.); (H.W.); (H.Y.Y.)
| | - Jaeyeon Park
- Environment and Resource Convergence Center, Advanced Institute of Convergence Technologies, Suwon 16229, Korea
| | - Jang-Seu Ki
- Department of Biotechnology, Sangmyung University, Seoul 03016, Korea; (H.K.); (H.P.); (H.W.); (H.Y.Y.)
| |
Collapse
|
10
|
Munoz M, Cirés S, de Pedro ZM, Colina JÁ, Velásquez-Figueroa Y, Carmona-Jiménez J, Caro-Borrero A, Salazar A, Santa María Fuster MC, Contreras D, Perona E, Quesada A, Casas JA. Overview of toxic cyanobacteria and cyanotoxins in Ibero-American freshwaters: Challenges for risk management and opportunities for removal by advanced technologies. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 761:143197. [PMID: 33160675 DOI: 10.1016/j.scitotenv.2020.143197] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/04/2020] [Accepted: 10/16/2020] [Indexed: 06/11/2023]
Abstract
The increasing occurrence of cyanobacterial blooms worldwide represents an important threat for both the environment and public health. In this context, the development of risk analysis and management tools as well as sustainable and cost-effective treatment processes is essential. The research project TALGENTOX, funded by the Ibero-American Science and Technology Program for Development (CYTED-2019), aims to address this ambitious challenge in countries with different environmental and social conditions within the Ibero-American context. It is based on a multidisciplinary approach that combines ecology, water management and technology fields, and includes research groups from Chile, Colombia, Mexico, Peru and Spain. In this review, the occurrence of toxic cyanobacteria and cyanotoxins in freshwaters from these countries are summarized. The presence of cyanotoxins has been confirmed in all countries but the information is still scarce and further monitoring is required. In this regard, remote sensing or metagenomics are good alternatives at reasonable cost. The risk management of freshwaters from those countries considering the most frequent uses (consumption and recreation) has been also evaluated. Only Spain and Peru include cyanotoxins in its drinking water legislation (only MC-LR) and thus, there is a need for regulatory improvements. The development of preventive strategies like diminishing nutrient loads to aquatic systems is also required. In the same line, corrective measures are urgently needed especially in drinking waters. Advanced Oxidation Processes (AOPs) have the potential to play a major role in this scenario as they are effective for the elimination of most cyanotoxins classes. The research on the field of AOPs is herein summarized considering the cost-effectiveness, environmental character and technical applicability of such technologies. Fenton-based processes and photocatalysis using solar irradiation or LED light represent very promising alternatives given their high cost-efficiency. Further research should focus on developing stable long-term operation systems, addressing their scale-up.
Collapse
Affiliation(s)
- Macarena Munoz
- Departamento de Ingeniería Química, Universidad Autónoma de Madrid, Madrid, Spain.
| | - Samuel Cirés
- Departamento de Biología, Universidad Autónoma de Madrid, Madrid, Spain.
| | - Zahara M de Pedro
- Departamento de Ingeniería Química, Universidad Autónoma de Madrid, Madrid, Spain
| | - José Ángel Colina
- Departamento de Ingeniería Química, Universidad de Cartagena, Cartagena de Indias, Colombia
| | | | - Javier Carmona-Jiménez
- Departamento de Ecología y Recursos Naturales, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Angela Caro-Borrero
- Departamento de Ecología y Recursos Naturales, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Anthony Salazar
- Centro de Investigación y Tecnología de Agua - CITA, Universidad de Ingeniería y Tecnología - UTEC, Lima, Peru
| | | | - David Contreras
- Centro de Biotecnología, Universidad de Concepción, Concepción, Chile
| | - Elvira Perona
- Departamento de Biología, Universidad Autónoma de Madrid, Madrid, Spain
| | - Antonio Quesada
- Departamento de Biología, Universidad Autónoma de Madrid, Madrid, Spain
| | - Jose A Casas
- Departamento de Ingeniería Química, Universidad Autónoma de Madrid, Madrid, Spain
| |
Collapse
|
11
|
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.
Collapse
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
| | | |
Collapse
|
12
|
Plaas HE, Paerl HW. Toxic Cyanobacteria: A Growing Threat to Water and Air Quality. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:44-64. [PMID: 33334098 DOI: 10.1021/acs.est.0c06653] [Citation(s) in RCA: 103] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The global expansion of harmful cyanobacterial blooms (CyanoHABs) poses an increasing threat to public health. CyanoHABs are characterized by the production of toxic metabolites known as cyanotoxins. Human exposure to cyanotoxins is challenging to forecast, and perhaps the least understood exposure route is via inhalation. While the aerosolization of toxins from marine harmful algal blooms (HABs) has been well documented, the aerosolization of cyanotoxins in freshwater systems remains understudied. In recent years, spray aerosol (SA) produced in the airshed of the Laurentian Great Lakes (United States and Canada) has been characterized, suggesting that freshwater systems may impact atmospheric aerosol loading more than previously understood. Therefore, further investigation regarding the impact of CyanoHABs on human respiratory health is warranted. This review examines current research on the incorporation of cyanobacterial cells and cyanotoxins into SA of aquatic ecosystems which experience HABs. We present an overview of cyanotoxin fate in the environment, biological incorporation into SA, existing data on cyanotoxins in SA, relevant collection methods, and adverse health outcomes associated with cyanotoxin inhalation.
Collapse
Affiliation(s)
- Haley E Plaas
- University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Chapel Hill, NC 27599, United States
- University of North Carolina at Chapel Hill, Institute of Marine Sciences, Morehead City, NC 28557, United States
| | - Hans W Paerl
- University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Chapel Hill, NC 27599, United States
- University of North Carolina at Chapel Hill, Institute of Marine Sciences, Morehead City, NC 28557, United States
| |
Collapse
|
13
|
Podduturi R, Schlüter L, Liu T, Osti JAS, Moraes MDAB, Jørgensen NOG. Monitoring of saxitoxin production in lakes in Denmark by molecular, chromatographic and microscopic approaches. HARMFUL ALGAE 2021; 101:101966. [PMID: 33526182 DOI: 10.1016/j.hal.2020.101966] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 12/03/2020] [Accepted: 12/05/2020] [Indexed: 06/12/2023]
Abstract
Diversity of phytoplankton in three eutrophic and two mesotrophic lakes in Denmark was determined by microscopic and HPLC pigment analyses to identify and quantify potential saxitoxin (STX) producing cyanobacteria. Potential dominant STX-producers were identified to the filamentous genera Dolichospermum, Cuspidothrix, Phormidium and Planktolyngbya. Presence of STX production was documented by extraction of five intracellular STXs that included (in declining concentration in the cyanobacteria) dc-neo-STX, neo-STX, dc-STX, STX and GTX. Total concentrations of the five STXs varied from 9 to 142 fg per potential STX producer, corresponding to 87 to 985 ng L-1 in the lakes. For molecular detection of the STX-producers, a quantitative PCR method was developed by design of a new robust primer set with broad coverage to target the sxtA gene that is common to all STX-producing cyanobacteria. After validation, copy numbers of the sxtA gene were determined to vary from about 104 (mesotrophic lakes) to 108 per mL (the most eutrophic lake). A moderate but significant correlation was observed between abundance of the sxtA copies and concentrations of the five intracellular STXs. The qPCR assay was found to be a rapid and robust procedure for quantification of STX producers. Saxitoxin and its analogs appeared not to cause health concerns in the lakes, but commercial fishing for pike perch in the most eutrophic lake should be monitored to test for food web accumulation of STXs.
Collapse
Affiliation(s)
- Raju Podduturi
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | | | - Tingting Liu
- Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | | | - Munique de Almeida Bispo Moraes
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, São Carlos, São Paulo, Brazil
| | - Niels O G Jørgensen
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark.
| |
Collapse
|
14
|
Menezes C, Valério E, Botelho MJ, Dias E. Isolation and Characterization of Cylindrospermopsis raciborskii Strains from Finished Drinking Water. Toxins (Basel) 2020; 12:toxins12010040. [PMID: 31936211 PMCID: PMC7020411 DOI: 10.3390/toxins12010040] [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: 11/21/2019] [Revised: 12/27/2019] [Accepted: 01/03/2020] [Indexed: 12/14/2022] Open
Abstract
In the summer of 2015, an intense cyanobacterial bloom producing geosmin/2-methylisoborneol (MIB) occurred in the Roxo freshwater reservoir in Alentejo, Portugal. The drinking water supplied from the Roxo water treatment plant (WTP) exhibited an unpleasant odor/taste and a significant cyanobacteria density was detected in the finished water at the exit of the WTP. Cyanobacteria were not evaluated downstream of the WTP, namely, at the city reservoir. The aim of this work was to isolate and characterize viable cyanobacteria present in finished water (exit of the WTP and city reservoir) that withstand conventional water treatment. Treated water samples collected at both sites were inoculated in Z8 culture medium to provide the conditions for putative cyanobacterial growth. After 30 days, filamentous cyanobacteria were observed in cultures inoculated with samples from the exit point of the WTP. Viable trichomes were isolated and identified as Cylindrospermopsis raciborskii by morphometric and molecular analysis. None of the isolates were cylindrospermopsin/microcystin producers, as confirmed by ELISA and amplification of corresponding genes (PS/PKS and mcyA-cd/mcyAB/mcyB). ELISA results were positive for saxitoxin, but saxitoxin and derivatives were not detected by liquid chromatography with fluorescence detection (LC-FLD), nor were their related genes (sxtA/sxtA4/sxtB/sxtM/sxtPer/sxtI). To our knowledge, this is the first report on the establishment of cultures of C. raciborskii that resisted water treatment processes.
Collapse
Affiliation(s)
- Carina Menezes
- Department of Environmental Health, National Institute of Health Dr. Ricardo Jorge (INSA), Av. Padre Cruz, 1649-016 Lisbon, Portugal; (C.M.); (E.V.)
| | - Elisabete Valério
- Department of Environmental Health, National Institute of Health Dr. Ricardo Jorge (INSA), Av. Padre Cruz, 1649-016 Lisbon, Portugal; (C.M.); (E.V.)
| | - Maria João Botelho
- Department of Sea and Marine Resources, Portuguese Institute for the Sea and Atmosphere (IPMA), Rua Alfredo Magalhães Ramalho, 6, 1495-006 Lisbon, Portugal;
| | - Elsa Dias
- Department of Environmental Health, National Institute of Health Dr. Ricardo Jorge (INSA), Av. Padre Cruz, 1649-016 Lisbon, Portugal; (C.M.); (E.V.)
- Centre for the Studies of Animal Science (CECA), Institute of Agrarian and Agri-Food Sciences and Technologies (ICETA), Oporto University, 4051-401 Oporto, Portugal
- Correspondence: ; Tel.: +35-1217519260
| |
Collapse
|
15
|
Casero MC, Velázquez D, Medina-Cobo M, Quesada A, Cirés S. Unmasking the identity of toxigenic cyanobacteria driving a multi-toxin bloom by high-throughput sequencing of cyanotoxins genes and 16S rRNA metabarcoding. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 665:367-378. [PMID: 30772567 DOI: 10.1016/j.scitotenv.2019.02.083] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 01/14/2019] [Accepted: 02/05/2019] [Indexed: 06/09/2023]
Abstract
Cyanobacterial harmful algal blooms (CyanoHABs) are complex communities that include coexisting toxic and non-toxic strains only distinguishable by genetic methods. This study shows a water-management oriented use of next generation sequencing (NGS) to specifically pinpoint toxigenic cyanobacteria within a bloom simultaneously containing three of the most widespread cyanotoxins (the hepatotoxins microcystins, MCs; and the neurotoxins anatoxin-a, ATX, and saxitoxins, STXs). The 2013 summer bloom in Rosarito reservoir (Spain) comprised 33 cyanobacterial OTUs based on 16S rRNA metabarcoding, 7 of which accounted for as much as 96.6% of the community. Cyanotoxins and their respective biosynthesis genes were concurrently present throughout the entire bloom event including: MCs and mcyE gene; ATX and anaF gene; and STXs and sxtI gene. NGS applied to amplicons of cyanotoxin-biosynthesis genes unveiled 6 toxigenic OTUs, comprising 3 involved in MCs production (Planktothrix agardhii and 2 Microcystis spp.), 2 in ATX production (Cuspidothrix issatschenkoi and Phormidium/Tychonema spp.) and 1 in STXs production (Aphanizomenon gracile). These toxigenic taxa were also present in 16S rRNA OTUs list and their relative abundance was positively correlated with the respective toxin concentrations. Our results point at MC-producing P. agardhii and ATX-producing C. issatschenkoi as the main contributors to the moderate toxin concentrations observed, and suggest that their distribution in Southern Europe is broader than previously thought. Our findings also stress the need for monitoring low-abundance cyanobacteria (<1% relative abundance) in cyanotoxicity studies, and provide novel data on the presence of picocyanobacteria and potentially ATX-producing benthic taxa (e.g., Phormidium) in deep thermally-stratified water bodies. This study showcases a straightforward use of amplicon metagenomics of cyanotoxin biosynthesis genes in a multi-toxin bloom thus illustrating the broad applicability of NGS for water management in risk-oriented monitoring of CyanoHABs.
Collapse
Affiliation(s)
- María Cristina Casero
- Departamento de Biología, C/Darwin, 2, Universidad Autónoma de Madrid, ES-28049 Madrid, Spain
| | - David Velázquez
- Departamento de Biología, C/Darwin, 2, Universidad Autónoma de Madrid, ES-28049 Madrid, Spain
| | - Miguel Medina-Cobo
- Centro de Estudios Hidrográficos, Paseo Bajo de la Virgen del Puerto, 3, CEDEX, ES-28005 Madrid, Spain
| | - Antonio Quesada
- Departamento de Biología, C/Darwin, 2, Universidad Autónoma de Madrid, ES-28049 Madrid, Spain
| | - Samuel Cirés
- Departamento de Biología, C/Darwin, 2, Universidad Autónoma de Madrid, ES-28049 Madrid, Spain.
| |
Collapse
|
16
|
Savadova K, Mazur-Marzec H, Karosienė J, Kasperovičienė J, Vitonytė I, Toruńska-Sitarz A, Koreivienė J. Effect of Increased Temperature on Native and Alien Nuisance Cyanobacteria from Temperate Lakes: An Experimental Approach. Toxins (Basel) 2018; 10:E445. [PMID: 30380769 PMCID: PMC6265895 DOI: 10.3390/toxins10110445] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/27/2018] [Accepted: 10/28/2018] [Indexed: 11/17/2022] Open
Abstract
In response to global warming, an increase in cyanobacterial blooms is expected. In this work, the response of two native species of Planktothrix agardhii and Aphanizomenon gracile, as well as the response of two species alien to Europe-Chrysosporum bergii and Sphaerospermopsis aphanizomenoides-to gradual temperature increase was tested. The northernmost point of alien species distribution in the European continent was recorded. The tested strains of native species were favoured at 20⁻28 °C. Alien species acted differently along temperature gradient and their growth rate was higher than native species. Temperature range of optimal growth rate for S. aphanizomenoides was similar to native species, while C. bergii was favoured at 26⁻30 °C but sensitive at 18⁻20 °C. Under all tested temperatures, non-toxic strains of the native cyanobacteria species prevailed over the toxic ones. In P. agardhii, the decrease in concentration of microcystins and other oligopeptides with the increasing temperature was related to higher growth rate. However, changes in saxitoxin concentration in A. gracile under different temperatures were not detected. Accommodating climate change perspectives, the current work showed a high necessity of further studies of temperature effect on distribution and toxicity of both native and alien cyanobacterial species.
Collapse
Affiliation(s)
- Ksenija Savadova
- Institute of Botany, Nature Research Centre, LT-08412 Vilnius, Lithuania.
| | - Hanna Mazur-Marzec
- Division of Marine Biotechnology, Faculty of Oceanography and Geography, University of Gdańsk, Marszałka J. Piłsudskiego 46, PL-81-378 Gdynia, Poland.
| | - Jūratė Karosienė
- Institute of Botany, Nature Research Centre, LT-08412 Vilnius, Lithuania.
| | | | - Irma Vitonytė
- Institute of Botany, Nature Research Centre, LT-08412 Vilnius, Lithuania.
| | - Anna Toruńska-Sitarz
- Division of Marine Biotechnology, Faculty of Oceanography and Geography, University of Gdańsk, Marszałka J. Piłsudskiego 46, PL-81-378 Gdynia, Poland.
| | - Judita Koreivienė
- Institute of Botany, Nature Research Centre, LT-08412 Vilnius, Lithuania.
| |
Collapse
|
17
|
Affiliation(s)
- Judy A. Westrick
- Lumigen Instrument Center, Department of Chemistry; Wayne State University; Detroit Mich
| | - David Szlag
- Department of Chemistry; Oakland University; Rochester Mich
| |
Collapse
|