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Cai P, Xu L, Yang J, Tian C, Wu X, Wang C, Xiao B. Differences in survivability and toxic potential among Microcystis colonies of different sizes in sediment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:118916-118927. [PMID: 37919509 DOI: 10.1007/s11356-023-30753-9] [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: 04/26/2023] [Accepted: 10/25/2023] [Indexed: 11/04/2023]
Abstract
Microcystis colonies have the ability to persist for extended periods in sediment and function as a "seed bank" for the succeeding summer bloom in water column. The colonial morphology and toxin production ability of Microcystis are important for their population maintenance and life history. However, it is unclear about the influence of the colony morphology and toxic potential of Microcystis colonies on their benthic process. To address this question, we classified field Microcystis samples into three groups based on their size (< 150 μm, 150-300 μm, and > 300 μm) and compared their survivability and toxic potential during culturing in sediment. The results showed that Microcystis colonies in sediments disappeared quickly at 25℃ but survived for long periods at 5℃. The survivability of smaller Microcystis colonies (< 300 μm) was significantly higher than that of larger ones (> 300 μm). The activities of catalase (CAT) were significantly increased in large colonies compared to small colonies at 15℃ and 25℃. Real-time PCR indicated that smaller colonies had higher proportion of potential toxic genotype, and Microcystis colonies cultured at 15℃ and 25℃ showed higher percentage of microcystin-producing genotype. These results indicate that Microcystis colonies survived longer at low temperature and that larger Microcystis colonies are more susceptible to oxidative stress in sediments. The difference of toxic potential of Microcystis colonies of different sizes in sediments may be related to their survival ability in sediments.
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Affiliation(s)
- Pei Cai
- Key Laboratory of Algal Biology of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lei Xu
- Key Laboratory of Algal Biology of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jiaojiao Yang
- Dianchi Lake Ecosystem Observation and Research Station of Yunnan Province, Kunming Dianchi & Plateau Lakes Institute, Kunming, 650228, China
| | - Cuicui Tian
- Key Laboratory of Algal Biology of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Xingqiang Wu
- Key Laboratory of Algal Biology of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Chunbo Wang
- Key Laboratory of Algal Biology of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.
| | - Bangding Xiao
- Key Laboratory of Algal Biology of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
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Yang Y, Wang H, Yan S, Wang T, Zhang P, Zhang H, Wang H, Hansson LA, Xu J. Chemodiversity of Cyanobacterial Toxins Driven by Future Scenarios of Climate Warming and Eutrophication. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:11767-11778. [PMID: 37535835 DOI: 10.1021/acs.est.3c02257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/05/2023]
Abstract
Climate change and eutrophication are two environmental threats that can alter the structure of freshwater ecosystems and their service functions, but we know little about how ecosystem structure and function will evolve in future scenarios of climate warming. Therefore, we created different experimental climate scenarios, including present-day conditions, a 3.0 °C increase in mean temperature, and a "heatwaves" scenario (i.e., an increase in temperature variability) to assess the effects of climate change on phytoplankton communities under simultaneous stress from eutrophication and herbicides. We show that the effects of climate warming, particularly heatwaves, are associated with elevated cyanobacterial abundances and toxin production, driven by a change from mainly nontoxic to toxic Microcystis spp. The reason for higher cyanobacterial toxin concentrations is likely an increase in abundances because under the dual pressures of climate warming and eutrophication individual Microcystis toxin-producing ability decreased. Eutrophication and higher temperatures significantly increased the biomass of Microcystis, leading to an increase in the cyanobacterial toxin concentrations. In contrast, warming alone did not produce higher cyanobacterial abundances or cyanobacterial toxin concentrations likely due to the depletion of the available nutrient pool. Similarly, the herbicide glyphosate alone did not affect abundances of any phytoplankton taxa. In the case of nutrient enrichment, cyanobacterial toxin concentrations were much higher than under warming alone due to a strong boost in biomass of potential cyanobacterial toxin producers. From a broader perspective our study shows that in a future warmer climate, nutrient loading has to be reduced if toxic cyanobacterial dominance is to be controlled.
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Affiliation(s)
- Yalan Yang
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, Hainan 570228, P. R. China
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P. R. China
| | - Huan Wang
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, Hainan 570228, P. R. China
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P. R. China
| | - Shuwen Yan
- Department of Environmental Science & Engineering, Fudan University, Shanghai 200438, P. R. China
| | - Tao Wang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P. R. China
| | - Peiyu Zhang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P. R. China
| | - Huan Zhang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P. R. China
| | - Hongxia Wang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P. R. China
| | - Lars-Anders Hansson
- Department of Biology/Aquatic Ecology, Ecology Building, Lund University, Lund SE-22100, Sweden
| | - Jun Xu
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, Hainan 570228, P. R. China
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, P. R. China
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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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Buratti FM, Manganelli M, Vichi S, Stefanelli M, Scardala S, Testai E, Funari E. Cyanotoxins: producing organisms, occurrence, toxicity, mechanism of action and human health toxicological risk evaluation. Arch Toxicol 2017; 91:1049-1130. [DOI: 10.1007/s00204-016-1913-6] [Citation(s) in RCA: 258] [Impact Index Per Article: 36.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 12/13/2016] [Indexed: 12/11/2022]
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Srikumar A, Krishna PS, Sivaramakrishna D, Kopfmann S, Hess WR, Swamy MJ, Lin-Chao S, Prakash JSS. The Ssl2245-Sll1130 Toxin-Antitoxin System Mediates Heat-induced Programmed Cell Death in Synechocystis sp. PCC6803. J Biol Chem 2017; 292:4222-4234. [PMID: 28104802 DOI: 10.1074/jbc.m116.748178] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 01/17/2017] [Indexed: 12/13/2022] Open
Abstract
Two putative heat-responsive genes, ssl2245 and sll1130, constitute an operon that also has characteristics of a toxin-antitoxin system, thus joining several enigmatic features. Closely related orthologs of Ssl2245 and Sll1130 exist in widely different bacteria, which thrive under environments with large fluctuations in temperature and salinity, among which some are thermo-epilithic biofilm-forming cyanobacteria. Transcriptome analyses revealed that the clustered regularly interspaced short palindromic repeats (CRISPR) genes as well as several hypothetical genes were commonly up-regulated in Δssl2245 and Δsll1130 mutants. Genes coding for heat shock proteins and pilins were also induced in Δsll1130 We observed that the majority of cells in a Δsll1130 mutant strain remained unicellular and viable after prolonged incubation at high temperature (50 °C). In contrast, the wild type formed large cell clumps of dead and live cells, indicating the attempt to form biofilms under harsh conditions. Furthermore, we observed that Sll1130 is a heat-stable ribonuclease whose activity was inhibited by Ssl2245 at optimal temperatures but not at high temperatures. In addition, we demonstrated that Ssl2245 is physically associated with Sll1130 by electrostatic interactions, thereby inhibiting its activity at optimal growth temperature. This association is lost upon exposure to heat, leaving Sll1130 to exhibit its ribonuclease activity. Thus, the activation of Sll1130 leads to the degradation of cellular RNA and thereby heat-induced programmed cell death that in turn supports the formation of a more resistant biofilm for the surviving cells. We suggest to designate Ssl2245 and Sll1130 as MazE and MazF, respectively.
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Affiliation(s)
- Afshan Srikumar
- From the Department of Biotechnology and Bioinformatics, School of Life Sciences and
| | - Pilla Sankara Krishna
- From the Department of Biotechnology and Bioinformatics, School of Life Sciences and
| | | | - Stefan Kopfmann
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, D-79104 Freiburg, Germany, and
| | - Wolfgang R Hess
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, D-79104 Freiburg, Germany, and
| | - Musti J Swamy
- School of Chemistry, University of Hyderabad, Hyderabad 500046, India
| | - Sue Lin-Chao
- Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan
| | - Jogadhenu S S Prakash
- From the Department of Biotechnology and Bioinformatics, School of Life Sciences and
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