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Wei J, Luo J, Peng T, Zhou P, Zhang J, Yang F. Comparative genomic analysis and functional investigations for MCs catabolism mechanisms and evolutionary dynamics of MCs-degrading bacteria in ecology. ENVIRONMENTAL RESEARCH 2024; 248:118336. [PMID: 38295970 DOI: 10.1016/j.envres.2024.118336] [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: 08/21/2023] [Revised: 01/06/2024] [Accepted: 01/27/2024] [Indexed: 02/07/2024]
Abstract
Microcystins (MCs) significantly threaten the ecosystem and public health. Biodegradation has emerged as a promising technology for removing MCs. Many MCs-degrading bacteria have been identified, including an indigenous bacterium Sphingopyxis sp. YF1 that could degrade MC-LR and Adda completely. Herein, we gained insight into the MCs biodegradation mechanisms and evolutionary dynamics of MCs-degrading bacteria, and revealed the toxic risks of the MCs degradation products. The biochemical characteristics and genetic repertoires of strain YF1 were explored. A comparative genomic analysis was performed on strain YF1 and six other MCs-degrading bacteria to investigate their functions. The degradation products were investigated, and the toxicity of the intermediates was analyzed through rigorous theoretical calculation. Strain YF1 might be a novel species that exhibited versatile substrate utilization capabilities. Many common genes and metabolic pathways were identified, shedding light on shared functions and catabolism in the MCs-degrading bacteria. The crucial genes involved in MCs catabolism mechanisms, including mlr and paa gene clusters, were identified successfully. These functional genes might experience horizontal gene transfer events, suggesting the evolutionary dynamics of these MCs-degrading bacteria in ecology. Moreover, the degradation products for MCs and Adda were summarized, and we found most of the intermediates exhibited lower toxicity to different organisms than the parent compound. These findings systematically revealed the MCs catabolism mechanisms and evolutionary dynamics of MCs-degrading bacteria. Consequently, this research contributed to the advancement of green biodegradation technology in aquatic ecology, which might protect human health from MCs.
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Affiliation(s)
- Jia Wei
- Xiangya School of Public Health, Central South University, Changsha, Hunan, 410078, China
| | - Jiayou Luo
- Xiangya School of Public Health, Central South University, Changsha, Hunan, 410078, China.
| | - Tangjian Peng
- Hunan Province Key Laboratory of Typical Environmental Pollution and Health Hazards, School of Public Health, University of South China, Hengyang, Hunan, 421001, China
| | - Pengji Zhou
- Hunan Province Key Laboratory of Typical Environmental Pollution and Health Hazards, School of Public Health, University of South China, Hengyang, Hunan, 421001, China
| | - Jiajia Zhang
- Xiangya School of Public Health, Central South University, Changsha, Hunan, 410078, China
| | - Fei Yang
- Xiangya School of Public Health, Central South University, Changsha, Hunan, 410078, China; Hunan Province Key Laboratory of Typical Environmental Pollution and Health Hazards, School of Public Health, University of South China, Hengyang, Hunan, 421001, China.
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Santos AA, Garrute FV, Magalhães VF, Pacheco ABF. Microcystin removal by microbial communities from a coastal lagoon: Influence of abiotic factors, bacterioplankton composition and estimated functions. HARMFUL ALGAE 2024; 135:102646. [PMID: 38830712 DOI: 10.1016/j.hal.2024.102646] [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: 12/11/2023] [Revised: 03/27/2024] [Accepted: 05/13/2024] [Indexed: 06/05/2024]
Abstract
Toxic cyanobacterial blooms present a substantial risk to public health due to the production of secondary metabolites, notably microcystins (MCs). Microcystin-LR (MC-LR) is the most prevalent and toxic variant in freshwater. MCs resist conventional water treatment methods, persistently impacting water quality. This study focused on an oligohaline shallow lagoon historically affected by MC-producing cyanobacteria, aiming to identify bacteria capable of degrading MC and investigating the influence of environmental factors on this process. While isolated strains did not exhibit MC degradation, microbial assemblages directly sourced from lagoon water removed MC-LR within seven days at 25 ºC and pH 8.0. The associated bacterial community demonstrated an increased abundance of bacterial taxa assigned to Methylophilales, and also Rhodospirillales and Rhodocyclales to a lesser extent. However, elevated atmospheric temperatures (45 ºC) and acidification (pH 5.0 and 3.0) hindered MC-LR removal, indicating that extreme environmental changes could contribute to prolonged MC persistence in the water column. This study highlights the importance of considering environmental conditions in order to develop strategies to mitigate cyanotoxin contamination in aquatic ecosystems.
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Affiliation(s)
- Allan A Santos
- Laboratory of Ecophysiology and Toxicology of Cyanobacteria, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Felipe V Garrute
- Laboratory of Ecophysiology and Toxicology of Cyanobacteria, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; Ultrasound Laboratory, Biomedical Engineering Program-COPPE, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; Biological Physics Laboratory, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Valéria F Magalhães
- Laboratory of Ecophysiology and Toxicology of Cyanobacteria, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Ana Beatriz F Pacheco
- Biological Physics Laboratory, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
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Ubero-Pascal N, Aboal M. Cyanobacteria and Macroinvertebrate Relationships in Freshwater Benthic Communities beyond Cytotoxicity. Toxins (Basel) 2024; 16:190. [PMID: 38668615 PMCID: PMC11054157 DOI: 10.3390/toxins16040190] [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: 02/29/2024] [Revised: 04/01/2024] [Accepted: 04/09/2024] [Indexed: 04/29/2024] Open
Abstract
Cyanobacteria are harmful algae that are monitored worldwide to prevent the effects of the toxins that they can produce. Most research efforts have focused on direct or indirect effects on human populations, with a view to gain easy accurate detection and quantification methods, mainly in planktic communities, but with increasing interest shown in benthos. However, cyanobacteria have played a fundamental role from the very beginning in both the development of our planet's biodiversity and the construction of new habitats. These organisms have colonized almost every possible planktic or benthic environment on earth, including the most extreme ones, and display a vast number of adaptations. All this explains why they are the most important or the only phototrophs in some habitats. The negative effects of cyanotoxins on macroinvertebrates have been demonstrated, but usually under conditions that are far from natural, and on forms of exposure, toxin concentration, or composition. The cohabitation of cyanobacteria with most invertebrate groups is long-standing and has probably contributed to the development of detoxification means, which would explain the survival of some species inside cyanobacteria colonies. This review focuses on benthic cyanobacteria, their capacity to produce several types of toxins, and their relationships with benthic macroinvertebrates beyond toxicity.
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Affiliation(s)
- Nicolás Ubero-Pascal
- Department of Zoology and Physical Anthropology, Faculty of Biology, Espinardo Campus, University of Murcia, E-30100 Murcia, Spain;
| | - Marina Aboal
- Laboratory of Algology, Faculty of Biology, Espinardo Campus, University of Murcia, E-30100 Murcia, Spain
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