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Jablonska M, Cerasino L, Boscaini A, Capelli C, Greco C, Krivograd Klemenčič A, Mischke U, Salmaso N, Kurmayer R. Distribution of toxigenic cyanobacteria in Alpine lakes and rivers as revealed by molecular screening. WATER RESEARCH 2024; 258:121783. [PMID: 38805870 DOI: 10.1016/j.watres.2024.121783] [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: 03/01/2024] [Revised: 05/09/2024] [Accepted: 05/13/2024] [Indexed: 05/30/2024]
Abstract
The increasing frequency of cyanobacteria blooms in waterbodies caused by ecosystem eutrophication could endanger human health. This risk can be mitigated by effective monitoring incorporating molecular methods. To date, most molecular studies on toxigenic cyanobacteria have been limited to microcystins (MCs), disregarding other cyanotoxins, to freshwater planktic habitats while ignoring benthic habitats, and to limited geographic areas (usually one or a few specific waterbodies). In this study, we used PCR-based methods including PCR product sequencing and chemical-analytical methods (LC-MS/MS) to screen many plankton (n = 123) and biofilm samples (n = 113) originating from 29 Alpine lakes and 18 rivers for their cyanotoxin production potential. Both mcyE (indicating MC synthesis) and anaC (indicating anatoxin (ATX) synthesis) gene fragments were able to qualitatively predict MC or ATX occurrence. The abundance of mcyE gene fragments was significantly related to MC concentrations in plankton samples (R2 = 0.61). mcyE gene fragments indicative of MC synthesis were most abundant in planktic samples (65 %) and were assigned to the genera Planktothrix and Microcystis. However, mcyE rarely occurred in biofilms of lakes and rivers, i.e., 4 % and 5 %, respectively, and were assigned to Microcystis, Planktothrix, and Nostoc. In contrast, anaC gene fragments occurred frequently in planktic samples (14 % assigned to Tychonema, Phormidium (Microcoleus), and Oscillatoria), but also in biofilms of lakes (49 %) and rivers (18 %) and were assigned to the genera Phormidium, Oscillatoria, and Nostocales. The cyrJ gene fragment indicating cylindrospermopsin synthesis occurred only once in plankton (assigned to Dolichospermum), while saxitoxin synthesis potential was not detected. For plankton samples, monomictic and less eutrophic conditions were positively related to mcyE/MC occurrence frequency, while oligomictic conditions were related to anaC/ATX frequency. The anaC/ATX frequency in biofilm was related to the lake habitats generally showing higher biodiversity as revealed from metabarcoding in a parallel study.
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Affiliation(s)
- Maša Jablonska
- National Institute of Biology, Večna pot 121, 1000 Ljubljana, Slovenia; University of Ljubljana, Slovenia; Research Department for Limnology, Universität Innsbruck, Mondseestrasse 9, 5310 Mondsee, Austria.
| | - Leonardo Cerasino
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
| | - Adriano Boscaini
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
| | - Camilla Capelli
- Institute of Earth Sciences, University of Applied Sciences and Arts of Southern Switzerland (SUPSI), Mendrisio, Switzerland
| | - Claudia Greco
- Italian Institute for Environmental Protection and Research (ISPRA), Ozzano dell'Emilia, Bologna, Italy
| | | | - Ute Mischke
- Bavarian Environment Agency, Ref. 83, Wielenbach, Germany
| | - Nico Salmaso
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy; NBFC, National Biodiversity Future Center, Palermo, Italy
| | - Rainer Kurmayer
- Research Department for Limnology, Universität Innsbruck, Mondseestrasse 9, 5310 Mondsee, Austria; Universität Innsbruck, Innrain 52, 6020 Innsbruck, Austria.
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Stoyneva-Gärtner M, Stefanova K, Uzunov B, Radkova M, Gärtner G. Cuspidothrix Is the First Genetically Proved Anatoxin A Producer in Bulgarian Lakes and Reservoirs. Toxins (Basel) 2022; 14:toxins14110778. [PMID: 36356028 PMCID: PMC9696308 DOI: 10.3390/toxins14110778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/01/2022] [Accepted: 11/08/2022] [Indexed: 11/12/2022] Open
Abstract
The paper presents the first proof of planktonic cyanoprokaryote genus Cuspidothrix as an anatoxin A (ATX) producer in Bulgarian wetlands. The results from polymerase chain reaction (PCR) obtained from two summer sampling campaigns in 26 selected lakes and reservoirs demonstrated presence of the anaC gene, responsible for ATX production in 21 strains of the genus. They were found in three waterbodies sampled in 2018 (coastal lake Vaya, coastal reservoir Poroy, inland reservoir Sinyata Reka) and in four waterbodies sampled in 2019 (inland reservoirs Duvanli, Koprinka, Plachidol 2, Sinyata Reka). The detected genetic diversity generally corresponds to the observations conducted by conventional light microscopy, by which we distinguished three species of Cuspidothrix (Cuspidothrix issatschenkoi, Cuspidothrix elenkinii and Cuspidothrix tropicalis, the latter considered alien in the country). Eleven strains showed high similarity to two sequences of C. issatschenkoi available from the National Centre for Biotechnology Information (NCBI). Ten other strains assembled in a group, which-in lack of available from NCBI genetic sequences-were presumed related to C. tropicalis and C. elenkinii after comparison with the results from light microscopy. Cuspidothrix strains found in Bulgarian waterbodies showed high genetic similarity to those isolated and sequenced from Asia (Japan, China) and Northern Europe (Norway, Finland).
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Affiliation(s)
| | - Katerina Stefanova
- AgroBio Institute, Bulgarian Agricultural Academy, BG-1164 Sofia, Bulgaria
| | - Blagoy Uzunov
- Faculty of Biology, Department of Botany, Sofia University, BG-1164 Sofia, Bulgaria
- Correspondence:
| | - Mariana Radkova
- AgroBio Institute, Bulgarian Agricultural Academy, BG-1164 Sofia, Bulgaria
| | - Georg Gärtner
- Institute of Botany, Innsbruck University, A-6020 Innsbruck, Austria
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Durán-Vinet B, Araya-Castro K, Chao TC, Wood SA, Gallardo V, Godoy K, Abanto M. Potential applications of CRISPR/Cas for next-generation biomonitoring of harmful algae blooms: A review. HARMFUL ALGAE 2021; 103:102027. [PMID: 33980455 DOI: 10.1016/j.hal.2021.102027] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 03/01/2021] [Accepted: 03/21/2021] [Indexed: 06/12/2023]
Abstract
Research on harmful algal and cyanobacterial blooms (HABs and CHABs) has risen dramatically due to their increasing global distribution, frequency, and intensity. These blooms jeopardize public health, ecosystem function, sustainability and can have negative economic impacts. Numerous monitoring programs have been established using light microscopy, liquid chromatography coupled to mass spectrometry (LC-MS), ELISA, and spectrophotometry to monitor HABs/CHABs outbreaks. Recently, DNA/RNA-based molecular methods have been integrated into these programs to replace or complement traditional methods through analyzing environmental DNA and RNA (eDNA/eRNA) with techniques such as quantitative polymerase chain reaction (qPCR), fluorescent in situ hybridization (FISH), sandwich hybridization assay (SHA), isothermal amplification methods, and microarrays. These have enabled the detection of rare or cryptic species, enhanced sample throughput, and reduced costs and the need for visual taxonomic expertise. However, these methods have limitations, such as the need for high capital investment in equipment or detection uncertainties, including determining whether organisms are viable. In this review, we discuss the potential of newly developed molecular diagnosis technology based on Clustered Regularly Interspaced Short Palindromic Repeats/Cas proteins (CRISPR/Cas), which utilizes the prokaryotic adaptative immune systems of bacteria and archaea. Cas12 and Cas13-based platforms can detect both DNA and RNA with attomolar sensitivity within an hour. CRISPR/Cas diagnostic is a rapid, inexpensive, specific, and ultrasensitive technology that, with some further development, will provide many new platforms that can be used for HABs/CHABs biomonitoring and research.
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Affiliation(s)
- B Durán-Vinet
- Scientific and Technological Bioresource Nucleus (BIOREN-UFRO), Genomics and Bioinformatics Unit, Universidad de La Frontera, Av. Francisco Salazar, 1145 Temuco, Chile; Bachelor of Biotechnology (Honours) Program, Faculty of Agricultural and Forestry Sciences, Universidad de La Frontera, Av. Francisco Salazar, 1145 Temuco, Chile.
| | - K Araya-Castro
- Doctoral Program in Science of Natural Resources, Universidad de La Frontera, Av. Francisco Salazar, 1145 Temuco, Chile
| | - T C Chao
- Institute of Environmental Change & Society, Department of Biology, University of Regina, Wascana Parkway, 3737 Regina, Canada
| | - S A Wood
- Coastal and Freshwater Group, Cawthron Institute, 98 Halifax Street East, Nelson 7010, New Zealand
| | - V Gallardo
- Scientific and Technological Bioresource Nucleus (BIOREN-UFRO), Genomics and Bioinformatics Unit, Universidad de La Frontera, Av. Francisco Salazar, 1145 Temuco, Chile; Bachelor of Biotechnology (Honours) Program, Faculty of Agricultural and Forestry Sciences, Universidad de La Frontera, Av. Francisco Salazar, 1145 Temuco, Chile
| | - K Godoy
- Scientific and Technological Bioresource Nucleus (BIOREN-UFRO), Microscopy and Flow Cytometry Unit, Universidad de La Frontera, Av. Francisco Salazar, 1145 Temuco, Chile
| | - M Abanto
- Scientific and Technological Bioresource Nucleus (BIOREN-UFRO), Genomics and Bioinformatics Unit, Universidad de La Frontera, Av. Francisco Salazar, 1145 Temuco, Chile
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Detection of Cyanotoxin-Producing Genes in a Eutrophic Reservoir (Billings Reservoir, São Paulo, Brazil). WATER 2020. [DOI: 10.3390/w12030903] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
CyanoHABs (cyanobacterial harmful algal blooms) are blooms of cyanobacteria capable of producing cyanotoxins, a large group of secondary metabolites that are toxic to most eukaryotes. In this work, the main aim was to evaluate the presence of multiple genes from each of the clusters responsible for biosynthesis of cyanotoxins (cylindrospermopsin, microcystin and saxitoxin) in total DNA obtained from sixteen environmental water samples by PCR. Microcystin gene mcyE was amplified in all analyzed samples. Among the cylindrospermopsin genes analyzed, only the cyrC gene was amplified from DNA obtained from three of sixteen samples. Of the three different saxitoxin genes analyzed, sxtB and sxtI were present in four and three of the sixteen samples studied, respectively, and sxtA did not show any positive result. Based on our results, we suggest caution when using only one gene from the full clusters responsible for biosynthesis of cyanotoxins, given that it may not be sufficient to confirm or exclude the toxigenic potential of a sample.
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Legrand B, Miras Y, Beauger A, Dussauze M, Latour D. Akinetes and ancient DNA reveal toxic cyanobacterial recurrences and their potential for resurrection in a 6700-year-old core from a eutrophic lake. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 687:1369-1380. [PMID: 31412470 DOI: 10.1016/j.scitotenv.2019.07.100] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 06/20/2019] [Accepted: 07/07/2019] [Indexed: 06/10/2023]
Abstract
In order to evaluate the recurrence of toxic cyanobacterial blooms and to determine the survival capabilities of the resistance cells through time, a sedimentary core spanning 6700 years was drilled in the eutrophic Lake Aydat. A multiproxy approach (density, magnetic susceptibility, XRF, pollen and non-pollen palynomorph analyses), was used initially to determine the sedimentation model and the land uses around the lake. Comparison with the akinete count revealed that Nostocales cyanobacteria have been present in Lake Aydat over a six thousand year period. This long-term cyanobacterial recurrence also highlights the past presence of both the anaC and mcyB genes, involved in anatoxin-a and microcystin biosynthesis, respectively, throughout the core. The first appearance of cyanobacteria seems to be linked to the natural damming of the river, while the large increase in akinete density around 1800 cal.yr BP can be correlated with the intensification of human activities (woodland clearance, crop planting, grazing, etc.) in the catchment area of the lake, and marks the beginning of a long period of eutrophication. This first investigation into the viability and germination potential of cyanobacteria over thousands of years reveals the ability of intact akinetes to undergo cell divisions even after 1800 years of sedimentation, which is 10 times longer than previously observed. This exceptional cellular resistance, coupled with the long-term eutrophic conditions of this lake, could partly explain the past and current recurrences of cyanobacterial proliferations.
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Affiliation(s)
- Benjamin Legrand
- Université Clermont Auvergne, CNRS, LMGE, F-63178 Aubière Cedex, France; ATHOS Environnement, 112 avenue du Brézet, 63100 Clermont-Ferrand, France.
| | - Yannick Miras
- Histoire Naturelle de l'Homme Préhistorique (HNHP), UMR 7194, CNRS, Département de Préhistoire, Muséum National d'Histoire Naturelle, Institut de Paléontologie Humaine, 1, rue René Panhard, 75013 Paris, France; GEOLAB, UMR 6042, CNRS, Université Clermont-Auvergne, F-63000 Clermont-Ferrand, France
| | - Aude Beauger
- GEOLAB, UMR 6042, CNRS, Université Clermont-Auvergne, F-63000 Clermont-Ferrand, France
| | - Matthieu Dussauze
- Université Clermont Auvergne, CNRS, LMGE, F-63178 Aubière Cedex, France
| | - Delphine Latour
- Université Clermont Auvergne, CNRS, LMGE, F-63178 Aubière Cedex, France
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The Diversity of Cyanobacterial Toxins on Structural Characterization, Distribution and Identification: A Systematic Review. Toxins (Basel) 2019; 11:toxins11090530. [PMID: 31547379 PMCID: PMC6784007 DOI: 10.3390/toxins11090530] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 09/06/2019] [Accepted: 09/09/2019] [Indexed: 11/19/2022] Open
Abstract
The widespread distribution of cyanobacteria in the aquatic environment is increasing the risk of water pollution caused by cyanotoxins, which poses a serious threat to human health. However, the structural characterization, distribution and identification techniques of cyanotoxins have not been comprehensively reviewed in previous studies. This paper aims to elaborate the existing information systematically on the diversity of cyanotoxins to identify valuable research avenues. According to the chemical structure, cyanotoxins are mainly classified into cyclic peptides, alkaloids, lipopeptides, nonprotein amino acids and lipoglycans. In terms of global distribution, the amount of cyanotoxins are unbalanced in different areas. The diversity of cyanotoxins is more obviously found in many developed countries than that in undeveloped countries. Moreover, the threat of cyanotoxins has promoted the development of identification and detection technology. Many emerging methods have been developed to detect cyanotoxins in the environment. This communication provides a comprehensive review of the diversity of cyanotoxins, and the detection and identification technology was discussed. This detailed information will be a valuable resource for identifying the various types of cyanotoxins which threaten the environment of different areas. The ability to accurately identify specific cyanotoxins is an obvious and essential aspect of cyanobacterial research.
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John N, Baker L, Ansell BRE, Newham S, Crosbie ND, Jex AR. First report of anatoxin-a producing cyanobacteria in Australia illustrates need to regularly up-date monitoring strategies in a shifting global distribution. Sci Rep 2019; 9:10894. [PMID: 31350418 PMCID: PMC6659621 DOI: 10.1038/s41598-019-46945-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 07/03/2019] [Indexed: 11/09/2022] Open
Abstract
Routine monitoring of toxic cyanobacteria depends on up-to-date epidemiological information about their distribution. In Australia, anatoxin producing cyanobacteria are not regularly tested for and thought to be rare if not absent from the continent. Our study investigated the presence of anatoxin-a (ATX-a) producing cyanobacteria in surface water samples (n = 226 from 67 sampling locations) collected from 2010 to 2017 across the state of Victoria, Australia. We (1) detected the presence and distribution of anaC (anatoxin-a synthetase C) gene sequences previously associated with various cyanobacteria, including Cuspidothrix issatschenkoi, Aphanizomenon sp., D. circinale, Anabaena sp., and Oscillatoria sp., from 31 sampling locations, and (2) determined the concentration of ATX-a in samples tested using ELISA, in two instances detected at >4 µg · L-1. These data present the first confirmation of ATX-a producers in Australia. Our study indicates that ATX-a should be included in regular testing of cyanobacterial blooms in Australia and highlights the importance of regular investigation of the distributions of toxic cyanobacteria worldwide, particularly amid the known expanding distribution of many cyanobacterial taxa in a period of increased eutrophication and rising surface water temperatures.
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Affiliation(s)
- Nijoy John
- Department of Veterinary Biosciences, The University of Melbourne, Parkville, Victoria, 3010, Australia.
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3052, Australia.
| | - Louise Baker
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3052, Australia
| | - Brendan R E Ansell
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3052, Australia
| | - Steven Newham
- Goulburn Valley Water, Shepparton, Victoria, 3630, Australia
| | - Nicholas D Crosbie
- Melbourne Water, Docklands, Victoria, 3008, Australia
- School of Civil and Environmental Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Aaron R Jex
- Department of Veterinary Biosciences, The University of Melbourne, Parkville, Victoria, 3010, Australia
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3052, Australia
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Echenique-Subiabre I, Tenon M, Humbert JF, Quiblier C. Spatial and Temporal Variability in the Development and Potential Toxicity of Phormidium Biofilms in the Tarn River, France. Toxins (Basel) 2018; 10:toxins10100418. [PMID: 30336603 PMCID: PMC6215143 DOI: 10.3390/toxins10100418] [Citation(s) in RCA: 10] [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: 08/30/2018] [Revised: 09/24/2018] [Accepted: 10/09/2018] [Indexed: 11/29/2022] Open
Abstract
Proliferation of Phormidium biofilms in rivers is becoming a worldwide sanitation problem for humans and animals, due to the ability of these bacteria to produce anatoxins. To better understand the environmental conditions that favor the development of Phormidium biofilms and the production of anatoxins, we monitored the formation of these biofilms and their toxins for two years in the Tarn River, biofilms from which are known to have caused the deaths of multiple dogs. As previously observed in New Zealand, Phormidium biofilm development occurred in riffle areas. The coverage of these biofilms at the bottom of the river exhibited strong spatial and temporal variations, but was positively correlated with water temperature and depth. Anatoxin-a was detected in less than 50% of the biofilms. The concentrations of these toxins in the biofilms exhibited high spatiotemporal variability, with the highest concentrations being recorded at the end of the summer period at the upstream sampling sites. These findings suggest that the maturity of the biofilms, combined with the local environmental conditions, have an impact on the production of anatoxin, making risk assessment for these benthic proliferations challenging.
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Affiliation(s)
- Isidora Echenique-Subiabre
- INRA, Sorbonne University, iEES Paris, 4 Place Jussieu, 75252 Paris CEDEX, France.
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Muséum National d'Histoire Naturelle, CNRS, Case 39, 57 rue Cuvier, 75005 Paris, France.
| | - Maxime Tenon
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Muséum National d'Histoire Naturelle, CNRS, Case 39, 57 rue Cuvier, 75005 Paris, France.
| | | | - Catherine Quiblier
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Muséum National d'Histoire Naturelle, CNRS, Case 39, 57 rue Cuvier, 75005 Paris, France.
- Department Sciences du Vivant, Paris Diderot University, 5 rue T. Mann, 75013 Paris, France.
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Ahn S, Magaña AA, Bozarth C, Shepardson J, Morré J, Dreher T, Maier CS. Integrated identification and quantification of cyanobacterial toxins from Pacific Northwest freshwaters by Liquid Chromatography and High-resolution Mass Spectrometry. J MEX CHEM SOC 2018; 62:10.29356/jmcs.v62i2.386. [PMID: 30214641 PMCID: PMC6133267 DOI: 10.29356/jmcs.v62i2.386] [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] [Indexed: 11/20/2022]
Abstract
The occurrence of harmful algal blooms in nutrient-rich freshwater bodies has increased world-wide, including in the Pacific Northwest. Some cyanobacterial genera have the potential to produce secondary metabolites that are highly toxic to humans, livestock and wildlife. Reliable methods for the detection of cyanobacterial toxins with high specificity and low limits of detection are in high demand. Here we test a relatively new hybrid high resolution accurate mass quadrupole time-of-flight mass spectrometry platform (TripleTOF) for the analysis of cyanobacterial toxins in freshwater samples. We developed a new method that allows the quantitative analysis of four commonly observed microcystin congeners (LR, LA, YR, and RR) and anatoxin-a in a 6-min LC run without solid-phase enrichment. Limits of detection for the microcystin congeners (LR, LA, YR, and RR) and anatoxin-a were <5 ng/L (200-fold lower than the guideline value of 1 μg/L as maximum allowable concentration of MC-LR in drinking water). The method was applied for screening freshwaters in the Pacific Northwest during the bloom and post-bloom periods. The use of high resolution mass spectrometry and concomitant high sensitivity detection of specific fragment ions with high mass accuracy provides an integrated approach for the simultaneous identification and quantification of cyanobacterial toxins. The method is sensitive enough for detecting the toxins in single Microcystis colonies.
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Affiliation(s)
- Soyoun Ahn
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, USA
| | | | - Connie Bozarth
- Department of Microbiology, Oregon State University, Corvallis, Oregon 97331, USA
| | - Jonathan Shepardson
- Department of Microbiology, Oregon State University, Corvallis, Oregon 97331, USA
| | - Jeffery Morré
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, USA
| | - Theo Dreher
- Department of Microbiology, Oregon State University, Corvallis, Oregon 97331, USA
- Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon 97331, USA
| | - Claudia S. Maier
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, USA
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Benthic Archives Reveal Recurrence and Dominance of Toxigenic Cyanobacteria in a Eutrophic Lake over the Last 220 Years. Toxins (Basel) 2017; 9:toxins9090271. [PMID: 28869578 PMCID: PMC5618204 DOI: 10.3390/toxins9090271] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 08/25/2017] [Accepted: 09/01/2017] [Indexed: 11/17/2022] Open
Abstract
Akinetes are resistant cells which have the ability to persist in sediment for several decades. We have investigated the temporal distribution of akinetes of two species, Dolichospermum macrosporum and Dolichospermum flos-aquae, in a sediment core sampled in Lake Aydat (France), which covers 220 years. The upper part, from 1907 to 2016, the number of akinetes fluctuated but stayed at high concentrations, especially for D. macrosporum in surface sediment (with the maximal value close to 6.10⁵ akinetes g DW-1 of sediment), suggesting a recurrence of blooms of this species which was probably closely related to anthropic eutrophication since the 1960s. Before 1907, the abundance of akinetes of both species was very low, suggesting only a modest presence of these cyanobacteria. In addition, the percentage of intact akinetes was different for each species, suggesting different ecological processes in the water column. This percentage also decreased with depth, revealing a reduction in germination potential over time. In addition, biosynthetic genes of anatoxin-a (anaC) and microcystin (mcyA) were detected. First results show a high occurrence of mcyA all down the core. In contrast, anaC gene was mostly detected in the surface sediment (since the 1980s), revealing a potentially more recent occurrence of this cyanotoxin in Lake Aydat which may be associated with the recurrence of blooms of D. macrosporum and thus with anthropic activities.
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Legrand B, Lamarque A, Sabart M, Latour D. Characterization of akinetes from cyanobacterial strains and lake sediment: A study of their resistance and toxic potential. HARMFUL ALGAE 2016; 59:42-50. [PMID: 28073505 DOI: 10.1016/j.hal.2016.09.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 09/13/2016] [Accepted: 09/15/2016] [Indexed: 06/06/2023]
Abstract
Nostocalean cyanobacteria are known to proliferate abundantly in eutrophic aquatic ecosystems, and to produce several cyanotoxins, including anatoxin-a. In this study, we investigated both the resistance and toxic potential of the akinetes (resistant cells), using cyanobacterial cultures and akinetes extracted from the sediment of Lake Aydat (France) sampled in the winter and spring. Intact and lysed akinetes were differentiated using a double control based on the autofluorescence of akinetes and SYTOX-green staining. The percentage of resistant akinetes found in several different abiotic stress conditions was highly variable, depending on the species and also on the sampling season. Thus, the resistance of akinetes and their ability to germinate seems to follow a species-specific process, and akinetes can undergo physiologic changes during the sedimentary phase of the Nostocale life cycle. This study also revealed the first evidence of anatoxin-a genes in akinetes, with anaC and anaF genes detected in akinetes from all cyanobacterial producer cultures. The low number of anaC genes, almost exclusively detected using nested PCR, in the sediment at Lake Aydat suggests a limited but existent past population of toxic Nostocales in this lake. Given the key role of akinetes in the annual cycle and subsequent summer proliferation, it can be interesting to integrate the surveillance of akinetes in the management of lakes exposed to recurrent cyanobacterial blooms.
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Affiliation(s)
- Benjamin Legrand
- Université Clermont Auvergne, Université Blaise Pascal, LMGE, BP 10448, Clermont-Ferrand F-63000, France; CNRS, UMR 6023, LMGE, BP 80026, Aubiere Cedex F-63171, France; Athos-environnement, 112 Avenue du Brézet, Clermont-Ferrand F-63100, France.
| | - Amélie Lamarque
- Université Clermont Auvergne, Université Blaise Pascal, LMGE, BP 10448, Clermont-Ferrand F-63000, France; CNRS, UMR 6023, LMGE, BP 80026, Aubiere Cedex F-63171, France
| | - Marion Sabart
- Université Clermont Auvergne, Université Blaise Pascal, LMGE, BP 10448, Clermont-Ferrand F-63000, France; CNRS, UMR 6023, LMGE, BP 80026, Aubiere Cedex F-63171, France
| | - Delphine Latour
- Université Clermont Auvergne, Université Blaise Pascal, LMGE, BP 10448, Clermont-Ferrand F-63000, France; CNRS, UMR 6023, LMGE, BP 80026, Aubiere Cedex F-63171, France
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