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Teng J, Song M, Xu Q, Zou Q, Zhang H, Yin C, Liu X, Liu Y, Yan H. Purification and Activity of the Second Recombinant Enzyme for Biodegrading Linearized Microcystins by Sphingopyxis sp. USTB-05. Toxins (Basel) 2023; 15:494. [PMID: 37624251 PMCID: PMC10467064 DOI: 10.3390/toxins15080494] [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: 05/30/2023] [Revised: 07/26/2023] [Accepted: 08/02/2023] [Indexed: 08/26/2023] Open
Abstract
Hepatotoxic microcystins (MCs) are produced and released by the harmful bloom-forming cyanobacteria, which severely threaten drinking water safety and human health due to their high toxicity, widespread distribution, and structural stability. The linearized microcystinase (MlrB) further hydrolyses the poisonous linearized MCs produced by the microcystinase-catalysed MCs to form tetrapeptides. Here, the purification and activity of MlrB were investigated. The results showed that the linearized products generated by 12.5 mg/L MC-LR and MC-RR were removed by purified recombinant MlrB at a protein concentration of 1 mg/L within 30 min. The high catalytic activity of MlrB can be obtained via heterologous expression and affinity purification, which lays the foundation for further studies on the properties and mechanism of MCs biodegradation enzymes.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Hai Yan
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China; (J.T.)
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Cao X, Cai J, Zhang Y, Liu C, Song M, Xu Q, Liu Y, Yan H. Biodegradation of Uric Acid by Bacillus paramycoides-YC02. Microorganisms 2023; 11:1989. [PMID: 37630550 PMCID: PMC10460076 DOI: 10.3390/microorganisms11081989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 07/28/2023] [Accepted: 07/31/2023] [Indexed: 08/27/2023] Open
Abstract
High serum uric acid levels, known as hyperuricemia (HUA), are associated with an increased risk of developing gout, chronic kidney disease, cardiovascular disease, diabetes, and other metabolic syndromes. In this study, a promising bacterial strain capable of biodegrading uric acid (UA) was successfully isolated from Baijiu cellar mud using UA as the sole carbon and energy source. The bacterial strain was identified as Bacillus paramycoides-YC02 through 16S rDNA sequence analysis. Under optimal culture conditions at an initial pH of 7.0 and 38 °C, YC02 completely biodegraded an initial UA concentration of 500 mg/L within 48 h. Furthermore, cell-free extracts of YC02 were found to catalyze and remove UA. These results demonstrate the strong biodegradation ability of YC02 toward UA. To gain further insight into the mechanisms underlying UA biodegradation by YC02, the draft genome of YC02 was sequenced using Illumina HiSeq. Subsequent analysis revealed the presence of gene1779 and gene2008, which encode for riboflavin kinase, flavin mononucleotide adenylyl transferase, and flavin adenine dinucleotide (FAD)-dependent urate hydroxylase. This annotation was based on GO or the KEEG database. These enzymes play a crucial role in the metabolism pathway, converting vitamin B2 to FAD and subsequently converting UA to 5-hydroxyisourate (HIU) with the assistance of FAD. Notably, HIU undergoes a slow non-enzymatic breakdown into 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline (OHCU) and (S)-allantoin. The findings of this study provide valuable insights into the metabolism pathway of UA biodegradation by B. paramycoides-YC02 and offer a potential avenue for the development of bacterioactive drugs against HUA and gout.
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Affiliation(s)
| | | | | | | | | | | | | | - Hai Yan
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China; (X.C.); (J.C.)
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Degradation of Three Microcystin Variants in the Presence of the Macrophyte Spirodela polyrhiza and the Associated Microbial Communities. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19106086. [PMID: 35627623 PMCID: PMC9142107 DOI: 10.3390/ijerph19106086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 05/07/2022] [Accepted: 05/15/2022] [Indexed: 11/23/2022]
Abstract
Cyanobacteria, which form water blooms all over the world, can produce a wide range of cyanotoxins such as hepatotoxic microcystins (MCs) and other biologically active metabolites harmful to living organisms, including humans. Microcystin biodegradation, particularly caused by bacteria, has been broadly documented; however, studies in this field focus mainly on strains isolated from natural aquatic environments. In this paper, the biodegradation of microcystin-RR (MC-RR), microcystin-LR (MC-LR), and microcystin-LF (MC-LF) after incubation with Spirodela polyrhiza and the associated microorganisms (which were cultured under laboratory conditions) is shown. The strongest MC biodegradation rate after nine days of incubation was observed for MC-RR, followed by MC-LR. No statistically significant decrease in the concentration of MC-LF was noted. Products of MC decomposition were detected via the HPLC method, and their highest number was found for MC-RR (six products with the retention time between 5.6 and 16.2 min), followed by MC-LR (two products with the retention time between 19.3 and 20.2 min). Although the decrease in MC-LF concentration was not significant, four MC-LF degradation products were detected with the retention time between 28.9 and 33.0 min. The results showed that MC-LF was the most stable and resistant MC variant under experimental conditions. No accumulation of MCs or their biodegradation products in S. polyrhiza was found. The findings suggest that the microorganisms (bacteria and algae) associated with S. polyrhiza could be responsible for the MC biodegradation observed. Therefore, there is a need to broaden the research on the biodegradation products detected and potential MC-degraders associated with plants.
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Genomic Analysis of Sphingopyxis sp. USTB-05 for Biodegrading Cyanobacterial Hepatotoxins. Toxins (Basel) 2022; 14:toxins14050333. [PMID: 35622580 PMCID: PMC9144602 DOI: 10.3390/toxins14050333] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 04/21/2022] [Accepted: 04/28/2022] [Indexed: 12/04/2022] Open
Abstract
Sphingopyxis sp. USTB-05, which we previously identified and examined, is a well-known bacterial strain for biodegrading cyanobacterial hepatotoxins of both nodularins (NODs) and microcystins (MCs). Although the pathways for biodegrading the different types of [D-Asp1] NOD, MC-YR, MC-LR and MC-RR by Sphingopyxis sp. USTB-05 were suggested, and several biodegradation genes were successfully cloned and expressed, the comprehensive genomic analysis of Sphingopyxis sp. USTB-05 was not reported. Here, based on second and third generation sequencing technology, we analyzed the whole genome of Sphingopyxis sp. USTB-05, which is 4,679,489 bp and contains 4,312 protein coding genes. There are 88 protein-coding genes related to the NODs and MCs biodegradation, of which 16 genes (bioA, hmgL, hypdh, speE, nspC, phy, spuC, murD, glsA, ansA, ocd, crnA, ald, gdhA, murC and murI) are unique. These genes for the transformation of phenylacetic acid CoA (PA-CoA) to CO2 were also found in Sphingopyxis sp. USTB-05. This study expands the understanding of the pathway for complete biodegradation of cyanobacterial hepatotoxins by Sphingopyxis sp. USTB-05.
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Hu C, Zuo Y, Peng L, Gan N, Song L. Widespread Distribution and Adaptive Degradation of Microcystin Degrader ( mlr-Genotype) in Lake Taihu, China. Toxins (Basel) 2021; 13:toxins13120864. [PMID: 34941702 PMCID: PMC8705652 DOI: 10.3390/toxins13120864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 11/30/2021] [Accepted: 12/01/2021] [Indexed: 11/16/2022] Open
Abstract
Microbial degradation is an important route for removing environmental microcystins (MCs). Here, we investigated the ecological distribution of microcystin degraders (mlr-genotype), and the relationship between the substrate specificity of the microcystin degrader and the profile of microcystin congener production in the habitat. We showed that microcystin degraders were widely distributed and closely associated with Microcystis abundance in Lake Taihu, China. We characterized an indigenous degrader, Sphingopyxis N5 in the northern Lake Taihu, and it metabolized six microcystin congeners in increasing order (RR > LR > YR > LA > LF and LW). Such a substrate-specificity pattern was congruent to the order of the dominance levels of these congeners in northern Lake Taihu. Furthermore, a meta-analysis on global microcystin degraders revealed that the substrate-specificity patterns varied geographically, but generally matched the profiles of microcystin congener production in the degrader habitats, and the indigenous degrader typically metabolized well the dominant MC congeners, but not the rare congeners in the habitat. This highlighted the phenotypic congruence between microcystin production and degradation in natural environments. We theorize that such congruence resulted from the metabolic adaptation of the indigenous degrader to the local microcystin congeners. Under the nutrient microcystin selection, the degraders might have evolved to better exploit the locally dominant congeners. This study provided the novel insight into the ecological distribution and adaptive degradation of microcystin degraders.
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Affiliation(s)
- Chenlin Hu
- State Key Laboratory of Fresh Water Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; (C.H.); (Y.Z.); (L.P.)
- Graduate School of Chinese Academy of Sciences, Beijing 100049, China
- College of Pharmacy, University of Houston, Houston, TX 77204, USA
| | - Yanxia Zuo
- State Key Laboratory of Fresh Water Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; (C.H.); (Y.Z.); (L.P.)
- Graduate School of Chinese Academy of Sciences, Beijing 100049, China
| | - Liang Peng
- State Key Laboratory of Fresh Water Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; (C.H.); (Y.Z.); (L.P.)
- Graduate School of Chinese Academy of Sciences, Beijing 100049, China
- Institute of Hydrobiology, Jinan University, Guangzhou 510632, China
| | - Nanqin Gan
- State Key Laboratory of Fresh Water Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; (C.H.); (Y.Z.); (L.P.)
- Correspondence: (N.G.); (L.S.)
| | - Lirong Song
- State Key Laboratory of Fresh Water Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; (C.H.); (Y.Z.); (L.P.)
- Correspondence: (N.G.); (L.S.)
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6
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Biodegradation of Nodularin by a Microcystin-Degrading Bacterium: Performance, Degradation Pathway, and Potential Application. Toxins (Basel) 2021; 13:toxins13110813. [PMID: 34822597 PMCID: PMC8618024 DOI: 10.3390/toxins13110813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/15/2021] [Accepted: 11/15/2021] [Indexed: 01/19/2023] Open
Abstract
Currently, studies worldwide have comprehensively recognized the importance of Sphingomonadaceae bacteria and the mlrCABD gene cluster in microcystin (MC) degradation. However, knowledge about their degradation of nodularin (NOD) is still unclear. In this study, the degradation mechanism of NOD by Sphingopyxis sp. m6, an efficient MC degrader isolated from Lake Taihu, was investigated in several aspects, including degradation ability, degradation products, and potential application. The strain degraded NOD of 0.50 mg/L with a zero-order rate constant of 0.1656 mg/L/d and a half-life of 36 h. The average degradation rate of NOD was significantly influenced by the temperature, pH, and initial toxin concentrations. Moreover, four different biodegradation products, linear NOD, tetrapeptide H-Glu-Mdhb-MeAsp-Arg-OH, tripeptide H-Mdhb-MeAsp-Arg-OH, and dipeptide H-MeAsp-Arg-OH, were identified, of which the latter two are the first reported. Furthermore, the four mlr genes were upregulated during NOD degradation. The microcystinase MlrA encoded by the mlrA gene hydrolyzes the Arg-Adda bond to generate linear NOD as the first step of NOD biodegradation. Notably, recombinant MlrA showed higher degradation activity and stronger environmental adaptability than the wild strain, suggesting future applications in NOD pollution remediation. This research proposes a relatively complete NOD microbial degradation pathway, which lays a foundation for exploring the mechanisms of NOD degradation by MC-degrading bacteria.
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Salter C, VanMensel D, Reid T, Birbeck J, Westrick J, Mundle SOC, Weisener CG. Investigating the microbial dynamics of microcystin-LR degradation in Lake Erie sand. CHEMOSPHERE 2021; 272:129873. [PMID: 33592515 DOI: 10.1016/j.chemosphere.2021.129873] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 01/27/2021] [Accepted: 02/04/2021] [Indexed: 06/12/2023]
Abstract
Cyanobacterial blooms and the associated hepatotoxins produced (e.g., microcystins, MCs) create a significant human health risk in freshwater lakes around the world, including Lake Erie. Though various physical and chemical treatment options are utilized, these are costly and their effectiveness decreases when other organics are present. Laboratory studies have identified a remediation option based on a mlr gene operon that can systematically degrade this toxin; however, studies on Lake Erie have been unable to amplify mlr genes from MC-degrading bacteria. These results suggest that either existing primers may be inefficient for broad identification of the mlr genes or that MC degradation genes and/or pathways may vary among bacterial taxa. To investigate the dynamics of the Lake Erie microbial community involved in the degradation of microcystin-LR (MC-LR), a flow-through column experiment using collected beach sand was conducted over a period of six weeks. Increasing concentrations of lake water spiked with MC-LR were continuously delivered to both biotic and abiotic (sterilized) sand columns, with influent and effluent MC-LR concentrations measured by LC-MS/MS. Despite the toxin concentrations far exceeding natural conditions during a bloom event (maximum dosage = 15.4 μg/L), MC-LR was completely removed within 21 h of contact time in the biotic columns. Stimulation of community taxa during the degradation process included Burkholderiaceae, Illumatobacteraceae, Pseudomonadaceae, Rhodocyclaceae and Nitrosomonadaceae. The overall results suggest several critical species may be required for the most complete and effective degradation of MC-LR.
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Affiliation(s)
- Chelsea Salter
- Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4, Canada
| | - Danielle VanMensel
- Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4, Canada
| | - Thomas Reid
- Environment and Climate Change Canada, 867 Lakeshore Road, Burlington, ON, L7R 1A1, Canada
| | - Johnna Birbeck
- Lumigen Instrument Center, Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | - Judy Westrick
- Lumigen Instrument Center, Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | - Scott O C Mundle
- Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4, Canada
| | - Christopher G Weisener
- Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4, Canada.
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Sharma M, Khurana H, Singh DN, Negi RK. The genus Sphingopyxis: Systematics, ecology, and bioremediation potential - A review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 280:111744. [PMID: 33280938 DOI: 10.1016/j.jenvman.2020.111744] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 11/22/2020] [Accepted: 11/24/2020] [Indexed: 06/12/2023]
Abstract
The genus Sphingopyxis was first reported in the year 2001. Phylogenetically, Sphingopyxis is well delineated from other genera Sphingobium, Sphingomonas and Novosphingobium of sphingomonads group, family Sphingomonadaceae of Proteobacteria. To date (at the time of writing), the genus Sphingopyxis comprises of twenty validly published species available in List of Prokaryotic Names with Standing in Nomenclature. Sphingopyxis spp. have been isolated from diverse niches including, agricultural soil, marine and fresh water, caves, activated sludge, thermal spring, oil and pesticide contaminated soil, and heavy metal contaminated sites. Sphingopyxis species have drawn considerable attention not only for their ability to survive under extreme environments, but also for their potential to degrade number of xenobiotics and other environmental contaminants that impose serious threat to human health. At present, genome sequence of both cultivable and non-cultivable strains (metagenome assembled genome) are available in the public databases (NCBI) and genome wide studies confirms the presence of mobile genetic elements and plethora of degradation genes and pathways making them a potential candidate for bioremediation. Beside genome wide predictions there are number of experimental evidences confirm the degradation potential of bacteria belonging to genus Sphingopyxis and also the production of different secondary metabolites that help them interact and survive in their ecological niches. This review provides detailed information on ecology, general characteristic and the significant implications of Sphingopyxis species in environmental management along with the bio-synthetic potential.
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Affiliation(s)
- Monika Sharma
- Fish Molecular Biology Laboratory, Department of Zoology, University of Delhi, Delhi-110007, India
| | - Himani Khurana
- Fish Molecular Biology Laboratory, Department of Zoology, University of Delhi, Delhi-110007, India
| | - Durgesh Narain Singh
- Bacterial Pathogenesis Laboratory, Department of Zoology, University of Delhi, Delhi-110007, India
| | - Ram Krishan Negi
- Fish Molecular Biology Laboratory, Department of Zoology, University of Delhi, Delhi-110007, India.
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Dexter J, McCormick AJ, Fu P, Dziga D. Microcystinase - a review of the natural occurrence, heterologous expression, and biotechnological application of MlrA. WATER RESEARCH 2021; 189:116646. [PMID: 33246218 DOI: 10.1016/j.watres.2020.116646] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 11/01/2020] [Accepted: 11/14/2020] [Indexed: 06/11/2023]
Abstract
Microcystinase (MlrA) was first described in 1996. Since then MlrA peptidase activity has proven to be both the most efficient enzymatic process and the most specific catalyst of all known microcystins detoxification pathways. Furthermore, MlrA and the MlrABC degradation pathway are presently the only enzymatic processes with clear genetic and biochemical descriptions available for microcystins degradation, greatly facilitating modern applied genetics for any relevant technological development. Recently, there has been increasing interest in the potential of sustainable, biologically inspired alternatives to current industrial practice, with note that biological microcystins degradation is the primary detoxification process found in nature. While previous reviews have broadly discussed microbial biodegradation processes, here we present a review focused specifically on MlrA. Following a general overview, we briefly highlight the initial discovery and present understanding of the MlrABC degradation pathway, before discussing the genetic and biochemical aspects of MlrA. We then review the potential biotechnology applications of MlrA in the context of available literature with emphasis on the optimization of MlrA for in situ applications including (i) direct modulation of Mlr activity within naturally existing populations, (ii) bioaugmentation of systems with introduced biodegradative capacity via whole cell biocatalysts, and (iii) bioremediation via direct MlrA application.
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Affiliation(s)
- Jason Dexter
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 31-007 Kraków, Poland; Cyanoworks, LLC, 1771 Haskell Rd., Olean, NY 14760, USA.
| | - Alistair J McCormick
- SynthSys & Institute of Molecular Plant Sciences, School of Biological Sciences, King's Buildings, University of Edinburgh, EH9 3BF, UK.
| | - Pengcheng Fu
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, 58 Renmin Avenue, Meilan District, Haikou, Hainan Province, 570228 China.
| | - Dariusz Dziga
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 31-007 Kraków, Poland.
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Liu H, Guo X, Liu L, Yan M, Li J, Hou S, Wan J, Feng L. Simultaneous Microcystin Degradation and Microcystis aeruginosa Inhibition with the Single Enzyme Microcystinase A. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:8811-8820. [PMID: 32463659 DOI: 10.1021/acs.est.0c02155] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Harmful Microcystis blooms (HMBs) seriously threaten the ecology of environments and human health. Microcystins (MCs) produced by Microcystis are powerful mediators of HMB induction and maintenance. In this study, microcystinase A (MlrA), an enzyme with MC-degrading ability, was successfully obtained at over 90% purity for the first time through overexpression in Escherichia coli K12 TB1. The obtained MlrA exhibited high stability at high temperature and under alkaline conditions, while also exhibiting a long half-life. MlrA selectively inhibited MC-producing Microcystis cultures, but had no effect on MC-nonproducing Synechocystis cultures. The inhibition mechanism of MlrA against Microcystis was investigated by evaluating the morphological and physiological characteristics of cultures. MlrA effectively degraded extracellular MCs and decreased the synthesis of intracellular MCs by causing downregulation of genes involved in the microcystin biosynthesis pathway. Concomitantly, MlrA inhibited Microcystis photosynthesis by causing the downregulated expression of important photosynthesis pathway genes and interrupting electron transport chain activities and pigment synthesis. Thus, MlrA achieved the inhibition of Microcystis growth by reducing its photosynthetic capacity and intracellular MC contents, while also degrading extracellular MCs. On the basis of these results, we propose a new paradigm to achieve the simultaneous removal of MCs and HMBs using the single enzyme characterized here.
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Affiliation(s)
- Honglin Liu
- Key Laboratory of Pesticide & Chemical Biology (CCNU), Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China
| | - Xiaoliang Guo
- Key Laboratory of Pesticide & Chemical Biology (CCNU), Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China
| | - Lei Liu
- Key Laboratory of Pesticide & Chemical Biology (CCNU), Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China
| | - Mingyue Yan
- Key Laboratory of Pesticide & Chemical Biology (CCNU), Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China
| | - Jiahui Li
- Key Laboratory of Pesticide & Chemical Biology (CCNU), Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China
| | - Shuyan Hou
- Key Laboratory of Pesticide & Chemical Biology (CCNU), Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China
| | - Jian Wan
- Key Laboratory of Pesticide & Chemical Biology (CCNU), Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China
| | - Lingling Feng
- Key Laboratory of Pesticide & Chemical Biology (CCNU), Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China
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11
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Santos A, Rachid C, Pacheco AB, Magalhães V. Biotic and abiotic factors affect microcystin-LR concentrations in water/sediment interface. Microbiol Res 2020; 236:126452. [DOI: 10.1016/j.micres.2020.126452] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 12/28/2019] [Accepted: 03/04/2020] [Indexed: 01/25/2023]
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12
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A Mini Review on Microcystins and Bacterial Degradation. Toxins (Basel) 2020; 12:toxins12040268. [PMID: 32326338 PMCID: PMC7232508 DOI: 10.3390/toxins12040268] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 04/08/2020] [Accepted: 04/11/2020] [Indexed: 02/02/2023] Open
Abstract
Microcystins (MCs) classified as hepatotoxic and carcinogenic are the most commonly reported cyanobacterial toxins found in the environment. Microcystis sp. possessing a series of MC synthesis genes (mcyA-mcyJ) are well documented for their excessive abundance, numerous bloom occurrences and MC producing capacity. About 246 variants of MC which exert severe animal and human health hazards through the inhibition of protein phosphatases (PP1 and PP2A) have been characterized. To minimize and prevent MC health consequences, the World Health Organization proposed 1 µg/L MC guidelines for safe drinking water quality. Further the utilization of bacteria that represent a promising biological treatment approach to degrade and remove MC from water bodies without harming the environment has gained global attention. Thus the present review described toxic effects and bacterial degradation of MCs.
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Wang J, Wang C, Li Q, Shen M, Bai P, Li J, Lin Y, Gan N, Li T, Zhao J. Microcystin-LR Degradation and Gene Regulation of Microcystin-Degrading Novosphingobium sp. THN1 at Different Carbon Concentrations. Front Microbiol 2019; 10:1750. [PMID: 31447804 PMCID: PMC6691742 DOI: 10.3389/fmicb.2019.01750] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 07/15/2019] [Indexed: 11/18/2022] Open
Abstract
The bacterium Novosphingobium sp. THN1 (THN1) is capable of degrading microcystin-LR (MC-LR). To study the ability of THN1 to degrade MC-LR and its possible mechanism(s) of regulation, we analyzed the effect of carbon concentrations on the degradation process. The MC-LR degradation rate peaked early and then declined during MC-LR biodegradation. Decreased levels of carbon in the medium caused the degradation peak to occur earlier. The expression of the functional gene mlrA, encoding a microcystinase, showed a similar trend to the MC-LR degradation rate at various carbon concentrations (r2 = 0.717, p < 0.05), suggesting that regulation of mlrA expression may play an important role in MC-LR degradation by THN1. The total bacterial biomass decreased when the carbon source was limited and did not correlate with the MC-LR degradation rate. Transcriptomic analysis showed that MC-LR degradation differentially regulated 62.16% (2597/4178) of THN1 genes. A considerable number of differentially expressed genes (DEGs) during MC-LR degradation encoded proteins related to carbon-, nitrogen-, and amino acid-related pathways. At 2 h of MC-LR degradation, most DEGs (29/33) involved in carbon and nitrogen metabolism were downregulated. This indicated that MC-LR may regulate carbon and nitrogen pathways of Novosphingobium sp. THN1. KEGG pathway analysis indicated that the upregulated DEGs during MC-LR degradation were mainly related to amino acid degradation and substrate metabolism pathways. Particularly, we detected increased expression of glutathione metabolism-related genes from transcriptomic data at 2 h of MC-LR degradation compared with the gene expression of 0 h, such as GST family protein, glutathione peroxidase, S-(hydroxymethyl) glutathione dehydrogenase, and glutathione-dependent disulfide-bond oxidoreductase that have been reported to be involved in microcystin degradation.
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Affiliation(s)
- Juanping Wang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China.,Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Zhongnan Hospital, Wuhan University, Wuhan, China
| | - Chang Wang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Qi Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Mengyuan Shen
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Peng Bai
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Jionghui Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yan Lin
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Nanqin Gan
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Tao Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Jindong Zhao
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,State Key Laboratory of Protein and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing, China
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14
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Kumar P, Hegde K, Brar SK, Cledon M, Kermanshahi-Pour A. Potential of biological approaches for cyanotoxin removal from drinking water: A review. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 172:488-503. [PMID: 30738231 DOI: 10.1016/j.ecoenv.2019.01.066] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 01/20/2019] [Accepted: 01/22/2019] [Indexed: 05/20/2023]
Abstract
Biological treatment of cyanotoxins has gained much importance in recent decades and holds a promise to work in coordination with various physicochemical treatments. In drinking water treatment plants (DWTPs), effective removal of cyanotoxins with reduced toxicity is a primary concern. Commonly used treatments, such as ozonation, chlorination or activated carbon, undergo significant changes in their operating conditions (mainly dosage) to counter the variation in different environmental parameters, such as pH, temperature, and high cyanotoxin concentration. Presence of metal ions, natural organic matter (NOM), and other chemicals demand higher dosage and hence affect the activation energy to efficiently break down the cyanotoxin molecule. Due to these higher dose requirements, the treatment leads to the formation of toxic metabolites at a concentration high enough to break the guideline values. Biological methods of cyanotoxin removal proceed via enzymatic pathway where the protein-encoding genes are often responsible for the compound breakdown into non-toxic metabolites. However, in contrast to the chemical treatment, the biological processes advance at a much slower kinetic rate, predominantly due to a longer onset period (high lag phase). In fact, more than 90% of the studies reported on the biological degradation of the cyanotoxins attribute the biodegradation to the bacterial suspension. This suspended growth limits the mass transfer kinetics due to the presence of metal ions, NOMs and, other oxidizable matter, which further prolongs the lag phase and makes biological process toxic-free, albeit less efficient. In this context, this review attempts to bring out the importance of the attached growth mechanism, in particular, the biofilm-based treatment approaches which can enhance the biodegradation rate.
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Affiliation(s)
- Pratik Kumar
- INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec, Canada G1K 9A9
| | | | - Satinder Kaur Brar
- INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec, Canada G1K 9A9; Department of Civil Engineering, Lassonde School of Engineering, York University, North York, Toronto, Ontario, Canada M3J 1P3.
| | - Maximiliano Cledon
- CIMAS (CONICET, UnComa, Rio Negro), Güemes 1030, San Antonio Oeste, Rio Negro, Argentina
| | - Azadeh Kermanshahi-Pour
- Biorefining and Remediation Laboratory, Department of Process Engineering and Applied Science, Dalhousie University, 1360 Barrington Street, Halifax, Nova Scotia, Canada B3J 1Z1
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15
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Qin L, Zhang X, Chen X, Wang K, Shen Y, Li D. Isolation of a Novel Microcystin-Degrading Bacterium and the Evolutionary Origin of mlr Gene Cluster. Toxins (Basel) 2019; 11:E269. [PMID: 31086114 PMCID: PMC6563193 DOI: 10.3390/toxins11050269] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 04/29/2019] [Accepted: 05/09/2019] [Indexed: 12/02/2022] Open
Abstract
The mlr-dependent biodegradation plays an essential role in the natural attenuation of microcystins (MCs) in eutrophic freshwater ecosystems. However, their evolutionary origin is still unclear due to the lack of mlr gene cluster sequences. In this study, a Sphingopyxis sp. strain X20 with high MC-degrading ability was isolated, and the mlrA gene activity was verified by heterologous expression. The whole sequence of the mlr gene cluster in strain X20 was obtained through PCR and thermal asymmetric interlaced (TAIL)-PCR, and then used for evolutionary origin analyses together with the sequences available in GenBank. Phylogenetic analyses of mlr gene clusters suggested that the four mlr genes had the same origin and evolutionary history. Genomic island analyses showed that there is a genomic island on the genome of sphingomonads that is capable of degrading MCs, on which the mlr gene cluster anchors. The concentrated distribution of the mlr gene cluster in sphingomonads implied that these genes have likely been present in the sphingomonads gene pool for a considerable time. Therefore, the mlr gene cluster may have initially entered into the genome of sphingomonads together with the genomic island by a horizontal gene transfer event, and then become inherited by some sphingomonads. The species other than sphingomonads have likely acquired mlr genes from sphingomonads by recently horizontal gene transfer due to the sporadic distribution of MC-degrading species and the mlr genes in them. Our results shed new light on the evolutionary origin of the mlr cluster and thus facilitate the interpretation of characteristic distribution of the mlr gene in bacteria and the understanding of whole mlr pathway.
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Affiliation(s)
- Lian Qin
- School of Resource and Enviro1nmental Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China.
| | - Xiaoxing Zhang
- School of Resource and Enviro1nmental Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China.
| | - Xiaoguo Chen
- School of Resource and Enviro1nmental Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China.
| | - Ke Wang
- School of Resource and Enviro1nmental Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China.
| | - Yitian Shen
- Lian Qin and Xiaoxing Zhang contributed equally to this work and are Co-Firstauthors.
| | - Dan Li
- School of Resource and Enviro1nmental Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China.
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16
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Ndlela LL, Oberholster PJ, Van Wyk JH, Cheng PH. A laboratory based exposure of Microcystis and Oscillatoria cyanobacterial isolates to heterotrophic bacteria. Toxicon 2019; 165:1-12. [PMID: 31004611 DOI: 10.1016/j.toxicon.2019.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 03/25/2019] [Accepted: 04/12/2019] [Indexed: 11/30/2022]
Abstract
Biological control of cyanobacteria is a viable means of controlling nuisance bloom occurrences; however the majority of studies done are against Microcystis sp., with a commonly lytic effect caused. Filamentous cyanobacteria such as Oscillatoria are not as extensively studied in this area of biological control and are often part of Microcystis dominated blooms. This study employed heterotrophic bacterial isolates selected from bloom waters that indicated potential predatory behaviour against both filamentous and colonial cyanobacterial isolates. In comparison to a known Bacillus isolate, which is often reported among bacterial control agents, three other bacteria isolates were tested as control agents against non-axenic Oscillatoria and Microcystis cyanobacterial cultures. Assessments of cyanobacterial cell responses to the bacteria were conducted through water chemistry, chlorophyll a, alkaline phosphatase activity, microscopy and cyanotoxin measurements. The changes in these parameters were compared to untreated cyanobacterial cultures where no bacteria were added. The study found that at ratios of bacteria half that of Microcystis, minimal changes in chlorophyll a were observed, whilst Oscillatoria showed a decreased chlorophyll a more in the presence of isolates 1 and 3w. The assessment of alkaline phosphatase activity showed decreased activity in both cyanobacterial isolates exposed to the bacteria, relative to the untreated control sample. Microscopy analysis through fluorescence indicated that the attachment of the bacteria to the surface of the cyanobacteria hampered with the fluorescence and scanning electron microscopy indicated that the cells were damaged by the addition of the bacterial isolates. Cyanotoxin detection through the ELISA kit testing indicated that there was toxin reduction in samples treated with the bacterial isolates, with the highest reduction being close to 60% in the case of Microcystis sp. treated with isolate 3w. Similar reductions were noted in the filamentous cyanobacterium Oscillatoria, in the presence of isolate 1.
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Affiliation(s)
- L L Ndlela
- Council for Scientific and Industrial Research, 11 Jan Celliers Road, Stellenbosch, 7600, South Africa; Department of Botany and Zoology, Faculty of Science, Stellenbosch University, Matieland 7600, South Africa.
| | - P J Oberholster
- Council for Scientific and Industrial Research, 11 Jan Celliers Road, Stellenbosch, 7600, South Africa; Department of Botany and Zoology, Faculty of Science, Stellenbosch University, Matieland 7600, South Africa
| | - J H Van Wyk
- Department of Botany and Zoology, Faculty of Science, Stellenbosch University, Matieland 7600, South Africa
| | - P H Cheng
- Council for Scientific and Industrial Research, 11 Jan Celliers Road, Stellenbosch, 7600, South Africa
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17
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Silva MOD, Desmond P, Derlon N, Morgenroth E, Pernthaler J. Source Community and Assembly Processes Affect the Efficiency of Microbial Microcystin Degradation on Drinking Water Filtration Membranes. Front Microbiol 2019; 10:843. [PMID: 31057530 PMCID: PMC6482319 DOI: 10.3389/fmicb.2019.00843] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 04/02/2019] [Indexed: 01/14/2023] Open
Abstract
Microbial biofilms in gravity-driven membrane (GDM) filtration systems can efficiently degrade the cyanotoxin microcystin (MC), but it is unclear if this function depends on the presence of MC-producing cyanobacteria in the source water habitat. We assessed the removal of MC from added Microcystis aeruginosa biomass in GDMs fed with water from a lake with regular blooms of toxic cyanobacteria (ExpL) or from a stream without such background (ExpS). While initial MC removal was exclusively due to abiotic processes, significantly higher biological MC removal was observed in ExpL. By contrast, there was no difference in MC degradation capacity between lake and stream bacteria in separately conducted liquid enrichments on pure MC. Co-occurrence network analysis revealed a pronounced modularity of the biofilm communities, with a clear hierarchic distinction according to feed water origin and treatment type. Genotypes in the network modules associated with ExpS had significantly more links to each other, indicating that these biofilms had assembled from a more coherent source community. In turn, signals for stochastic community assembly were stronger in ExpL biofilms. We propose that the less "tightly knit" ExpL biofilm assemblages allowed for the better establishment of facultatively MC degrading bacteria, and thus for higher overall functional efficiency.
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Affiliation(s)
- Marisa O. D. Silva
- Limnological Station, Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Peter Desmond
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
- Institute of Environmental Engineering, ETH Zurich, Institute of Environmental Engineering, Zurich, Switzerland
| | - Nicolas Derlon
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - Eberhard Morgenroth
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
- Institute of Environmental Engineering, ETH Zurich, Institute of Environmental Engineering, Zurich, Switzerland
| | - Jakob Pernthaler
- Limnological Station, Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
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18
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Ding Q, Liu K, Xu K, Sun R, Zhang J, Yin L, Pu Y. Further Understanding of Degradation Pathways of Microcystin-LR by an Indigenous Sphingopyxis sp. in Environmentally Relevant Pollution Concentrations. Toxins (Basel) 2018; 10:toxins10120536. [PMID: 30558170 PMCID: PMC6315713 DOI: 10.3390/toxins10120536] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 12/03/2018] [Accepted: 12/12/2018] [Indexed: 11/16/2022] Open
Abstract
Microcystin-LR (MC-LR) is the most widely distributed microcystin (MC) that is hazardous to environmental safety and public health, due to high toxicity. Microbial degradation is regarded as an effective and environment-friendly method to remove it, however, the performance of MC-degrading bacteria in environmentally relevant pollution concentrations of MC-LR and the degradation pathways remain unclear. In this study, one autochthonous bacterium, Sphingopyxis sp. m6 which exhibited high MC-LR degradation ability, was isolated from Lake Taihu, and the degrading characteristics in environmentally relevant pollution concentrations were demonstrated. In addition, degradation products were identified by utilizing the full scan mode of UPLC-MS/MS. The data illustrated that strain m6 could decompose MC-LR (1–50 μg/L) completely within 4 h. The degradation rates were significantly affected by temperatures, pH and MC-LR concentrations. Moreover, except for the typical degradation products of MC-LR (linearized MC-LR, tetrapeptide, and Adda), there were 8 different products identified, namely, three tripeptides (Adda-Glu-Mdha, Glu-Mdha-Ala, and Leu-MeAsp-Arg), three dipeptides (Glu-Mdha, Mdha-Ala, and MeAsp-Arg) and two amino acids (Leu, and Arg). To our knowledge, this is the first report of Mdha-Ala, MeAsp-Arg, and Leu as MC-LR metabolites. This study expanded microbial degradation pathways of MC-LR, which lays a foundation for exploring degradation mechanisms and eliminating the pollution of microcystins (MCs).
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Affiliation(s)
- Qin Ding
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education of China, School of Public Health, Southeast University, Nanjing 210009, China.
| | - Kaiyan Liu
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education of China, School of Public Health, Southeast University, Nanjing 210009, China.
| | - Kai Xu
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education of China, School of Public Health, Southeast University, Nanjing 210009, China.
| | - Rongli Sun
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education of China, School of Public Health, Southeast University, Nanjing 210009, China.
| | - Juan Zhang
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education of China, School of Public Health, Southeast University, Nanjing 210009, China.
| | - Lihong Yin
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education of China, School of Public Health, Southeast University, Nanjing 210009, China.
| | - Yuepu Pu
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education of China, School of Public Health, Southeast University, Nanjing 210009, China.
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19
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Morón-López J, Nieto-Reyes L, El-Shehawy R. Assessment of the influence of key abiotic factors on the alternative microcystin degradation pathway(s) (mlr -): A detailed comparison with the mlr route (mlr +). THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 599-600:1945-1953. [PMID: 28549370 DOI: 10.1016/j.scitotenv.2017.04.042] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 04/06/2017] [Accepted: 04/06/2017] [Indexed: 06/07/2023]
Abstract
Cyanobacterial proliferation and toxin production in water bodies around the world have led to global concern about the control of these issues. Indigenous bacteria have been shown to degrade the cyanotoxin microcystin (MC) in natural environments. The mlr cluster has been widely used as a marker for microcystin biodegradation; however, recent studies have shown that alternative pathway(s) also contribute to the natural removal of MCs in the ecosystem. The main objective of this study is to provide initial insights concerning how key abiotic factors affect the rate of MC biodegradation via alternative pathway(s) and to provide a detailed comparison with the mlr+ pathway. Our results show that nutrient inputs and previous exposure to MCs trigger changes in the rate of MC degradation via alternative pathway(s), while temperature does not produce any significant change. Our results further indicate that the alternative pathway(s) may be less efficient at degrading MCs than the mlr+ pathway, suggesting the importance of microbial diversity in determining the half-life of MCs in the water column.
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20
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Shi L, Huang Y, Zhang M, Yu Y, Lu Y, Kong F. Bacterial community dynamics and functional variation during the long-term decomposition of cyanobacterial blooms in-vitro. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 598:77-86. [PMID: 28437774 DOI: 10.1016/j.scitotenv.2017.04.115] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Revised: 04/13/2017] [Accepted: 04/14/2017] [Indexed: 06/07/2023]
Abstract
Cyanobacterial blooms drastically influence carbon and nutrient cycling in eutrophic freshwater lakes. To understand the mineralization process of cyanobacteria-derived particulate organic matter (CyanPOM), the aerobic degradation of cyanobacterial blooms dominated by Microcystis sp. was investigated over a 95-day microcosm experiment. Approximately 91%, 95% and 83% of the initial particulate organic carbon (POC), particulate organic nitrogen (PON), and particulate organic phosphorus (POP) were decomposed, respectively. The POC:PON ratio gradually increased from 5.9 to 13.5, whereas the POC:POP ratio gradually decreased from 230.3 to 120. These results indicated that the coupling of POC, PON, and POP changed during the decomposition of CyanPOM. Moreover, approximately 29%, 51% and 46% of POC, PON, and POP were mineralized to dissolved organic carbon, NO3-, and PO43-, respectively. Rhodospirillales (10.9%), Burkholderiales (16.5%), and Verrucomicrobiales (14.3%) dominated during the rapid phase (days 0-21), whereas Sphingomonadales (12.8%), Rhizobiales (11.8%), and Xanthomonadales (36.5%) dominated during the slow phase (days 21-50) of CyanPOM decomposition. Nitrospira (16.6%-32.9%) dominated and NO3- increased during the refractory phase (days 50-95), thus suggesting the occurrence of nitrification. Redundancy analysis revealed that bacterial communities during rapid decomposition were distinct from those during the slow and refractory periods. POC:POP, NH4+, and NO3- were the major driving factors for the patterns of bacterial communities. Furthermore, increase in nitrogen metabolism, methane metabolism, amino acid related enzymes and pyruvate metabolism characterized the functional variation of bacterial communities during degradation. Therefore, CyanPOM is an important nutrient source, and its decomposition level shapes bacterial communities.
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Affiliation(s)
- Limei Shi
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, China.
| | - Yaxin Huang
- Biological Experiment Teaching Center, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Min Zhang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, China
| | - Yang Yu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, China
| | - Yaping Lu
- Biological Experiment Teaching Center, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Fanxiang Kong
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, China.
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21
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Dziga D, Maksylewicz A, Maroszek M, Budzyńska A, Napiorkowska-Krzebietke A, Toporowska M, Grabowska M, Kozak A, Rosińska J, Meriluoto J. The biodegradation of microcystins in temperate freshwater bodies with previous cyanobacterial history. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2017; 145:420-430. [PMID: 28772230 DOI: 10.1016/j.ecoenv.2017.07.046] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 07/17/2017] [Accepted: 07/18/2017] [Indexed: 06/07/2023]
Abstract
Cyanobacterial blooms and cyanotoxins occur in freshwater lakes and reservoirs all over the world. Bacterial degradation of microcystins (MC), hepatotoxins produced by several cyanobacterial species, has also been broadly documented. However, information regarding MC biodegradation in European water bodies is very limited. In this paper, the occurrence and identification of MC biodegradation products was documented for 21 European lakes and reservoirs, many of which have well-documented cyanobacterial bloom histories. Varying cyanobacterial abundance and taxonomical composition were documented and MC producers were found in all the analysed samples. Planktothrix agardhii was the most common cyanobacterial species and it formed mass occurrences in four lakes. MC biodegradation was observed in 86% of the samples (18 out of 21), and four products of dmMC-LR decomposition were detected by HPLC and LC-MS methods. The two main products were cyclic dmMC-LR with modifications in the Arg-Asp-Leu region; additionally one product was recognized as the tetrapeptide Adda-Glu-Mdha-Ala. The composition of the detected products suggested a new biochemical pathway of MC degradation. The results confirmed the hypothesis that microcystin biodegradation is a common phenomenon in central European waters and that it may occur by a mechanism which is different from the one previously reported. Such a finding implies the necessity to develop a more accurate methodology for screening bacteria with MC biodegradation ability. Furthermore, it warrants new basic and applied studies on the characterization and utilization of new MC-degrading strains and biodegradation pathways.
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Affiliation(s)
- Dariusz Dziga
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30387 Krakow, Poland.
| | - Anna Maksylewicz
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30387 Krakow, Poland
| | - Magdalena Maroszek
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30387 Krakow, Poland
| | - Agnieszka Budzyńska
- Department of Water Protection, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61614 Poznań, Poland
| | | | - Magdalena Toporowska
- Department of Hydrobiology, University of Life Sciences in Lublin, Dobrzańskiego 37, 20262 Lublin, Poland
| | - Magdalena Grabowska
- Department of Hydrobiology, University of Białystok, Ciołkowskiego 1J, 15245 Białystok, Poland
| | - Anna Kozak
- Department of Water Protection, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61614 Poznań, Poland
| | - Joanna Rosińska
- Department of Water Protection, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61614 Poznań, Poland
| | - Jussi Meriluoto
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Tykistökatu 6A, 20520 Turku, Finland
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22
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A Novel and Native Microcystin-Degrading Bacterium of Sphingopyxis sp. Isolated from Lake Taihu. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2017; 14:ijerph14101187. [PMID: 28984840 PMCID: PMC5664688 DOI: 10.3390/ijerph14101187] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 09/28/2017] [Accepted: 09/30/2017] [Indexed: 11/22/2022]
Abstract
A native, highly efficient microcystin-LR (MC-LR)-degrading bacterium named a7 was isolated from Lake Taihu and identified as Sphingopyxis sp. by 16S rDNA sequence analysis. The strain a7 could totally degrade MC-LR at a rate of 3.33 mg/(L·h), as detected by high-performance liquid chromatography (HPLC). The mlrA, mlrC, and mlrD genes were detected in the strain a7 by sequence analysis. Tetrapeptide and Adda—which are the middle metabolites of MC-LR—were analyzed via liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS) during degradation. These metabolites were degraded completely, which suggested that the native Sphingopyxis sp. a7 was highly efficient in MC-LR degradation under bench conditions. Thus, strain a7 exhibited a significant potential application for bioremediation in water bodies contaminated by MC-LR produced by harmful cyanobacterial blooms.
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23
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Umehara A, Takahashi T, Komorita T, Orita R, Choi JW, Takenaka R, Mabuchi R, Park HD, Tsutsumi H. Widespread dispersal and bio-accumulation of toxic microcystins in benthic marine ecosystems. CHEMOSPHERE 2017; 167:492-500. [PMID: 27756043 DOI: 10.1016/j.chemosphere.2016.10.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 08/31/2016] [Accepted: 10/10/2016] [Indexed: 05/21/2023]
Abstract
Freshwater cyanobacteria produce toxic microcystins (MCs), which travel from freshwater areas into the sea. The MCs produced by cyanobacteria in a freshwater reservoir were discharged frequently into the adjacent Isahaya Bay, remained in the surface sediments, and then accumulated in various macrobenthic animals on the seafloor. The MCs were transported further outside of Isahaya Bay (Ariake Bay), and the median values of the MC contents in the sediments were in the same levels in both bays, while their temporal variations were also similar during the study period. Therefore, the fluctuations of the MC contents in the surface sediments were physically controlled by the timing of the discharge from the reservoir. The MC contents in polychaetes and oysters collected in Isahaya Bay increased markedly during winter. The median values of the carbon-based MC contents in the sediments, primary consumers, and secondary consumers in the bay were 87, 160, and 250 ngMC gC-1, respectively. These results demonstrated bio-accumulation at lower trophic levels in benthic marine ecosystems. An understanding of the processes occurring between sediments and macrobenthic animals is important for clarifying MC dynamics in ecosystems.
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Affiliation(s)
- Akira Umehara
- Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, 3-1-100 Tsukide, Kumamoto, 862-8502, Japan.
| | - Tohru Takahashi
- Department of Medical Technology, Kumamoto Health Science University, 325 Izumi-machi, Kumamoto, 861-5598, Japan
| | - Tomohiro Komorita
- Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, 3-1-100 Tsukide, Kumamoto, 862-8502, Japan
| | - Ryo Orita
- Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, 3-1-100 Tsukide, Kumamoto, 862-8502, Japan
| | - Jin-Woo Choi
- Korea Institute of Ocean Science and Technology, 41 Jangmok 1-gil, Jangmok-Myon, Geoji, 656-834, Republic of Korea
| | - Risa Takenaka
- Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, 3-1-100 Tsukide, Kumamoto, 862-8502, Japan
| | - Rie Mabuchi
- Department of Environmental Science, Faculty of Science, Shinshu University, Matsumoto, 390-8621, Japan
| | - Ho-Dong Park
- Department of Environmental Science, Faculty of Science, Shinshu University, Matsumoto, 390-8621, Japan
| | - Hiroaki Tsutsumi
- Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, 3-1-100 Tsukide, Kumamoto, 862-8502, Japan
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24
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He X, Liu YL, Conklin A, Westrick J, Weavers LK, Dionysiou DD, Lenhart JJ, Mouser PJ, Szlag D, Walker HW. Toxic cyanobacteria and drinking water: Impacts, detection, and treatment. HARMFUL ALGAE 2016; 54:174-193. [PMID: 28073475 DOI: 10.1016/j.hal.2016.01.001] [Citation(s) in RCA: 145] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 01/06/2016] [Indexed: 05/06/2023]
Abstract
Blooms of toxic cyanobacteria in water supply systems are a global issue affecting water supplies on every major continent except Antarctica. The occurrence of toxic cyanobacteria in freshwater is increasing in both frequency and distribution. The protection of water supplies has therefore become increasingly more challenging. To reduce the risk from toxic cyanobacterial blooms in drinking water, a multi-barrier approach is needed, consisting of prevention, source control, treatment optimization, and monitoring. In this paper, current research on some of the critical elements of this multi-barrier approach are reviewed and synthesized, with an emphasis on the effectiveness of water treatment technologies for removing cyanobacteria and related toxic compounds. This paper synthesizes and updates a number of previous review articles on various aspects of this multi-barrier approach in order to provide a holistic resource for researchers, water managers and engineers, as well as water treatment plant operators.
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Affiliation(s)
- Xuexiang He
- Southern Nevada Water Authority, PO Box 99954, Las Vegas, NV 89193, USA
| | - Yen-Ling Liu
- Department of Civil, Environmental and Geodetic Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - Amanda Conklin
- Department of Civil, Environmental and Geodetic Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - Judy Westrick
- Department of Chemistry, Wayne State University, Detroit, MI 48202, USA
| | - Linda K Weavers
- Department of Civil, Environmental and Geodetic Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - Dionysios D Dionysiou
- Environmental Engineering and Science Program, University of Cincinnati, Cincinnati, OH 45221, USA
| | - John J Lenhart
- Department of Civil, Environmental and Geodetic Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - Paula J Mouser
- Department of Civil, Environmental and Geodetic Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - David Szlag
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA
| | - Harold W Walker
- Department of Civil Engineering, Stony Brook University, Stony Brook, NY 11794, USA.
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Li H, Pan G. Simultaneous removal of harmful algal blooms and microcystins using microorganism- and chitosan-modified local soil. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:6249-6256. [PMID: 25901393 DOI: 10.1021/acs.est.5b00840] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Cyanobacterial harmful algal blooms (cyano-HAB) and microcystins (MCs) can cause a potential threat to public health. Here, a method for simultaneous removal of cyano-HAB and MCs was developed using chitosan-modified local soil (MLS) flocculation plus microorganism-modified soil capping. The experiment was conducted in simulated columns containing algal water collected from Lake Taihu (China). More than 90% of algal cells and intracellular MCs were flocculated and removed from water using chitosan-MLS and the sunken flocs were treated by different capping materials including Pseudomonas sp. An18 modified local soil. During 40 days of incubation, dissolved MC-LR and MC-RR showed 10-fold increase in the flocculation-only system. The increase of MC-LR and MC-RR in water was reduced by 30 and 70% in soil capping treatments; however, the total content of MCs in the sediment-water column remained similar to that in the control and flocculation only systems. In contrast, both dissolved MCs and total MCs were reduced by 90% in Pseudomonas sp. An18 modified soil capping treatment. The high performance of toxin decomposition was due to the combined effects of flocculation and MC-degrading bacteria that embedded in the capping material, which prevents dilution of bacteria biomass, concentrates algal cells, confines released toxins, and enhances toxin biodegradation.
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Affiliation(s)
- Hong Li
- †Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085, China
- ‡Institute of Biology, Guizhou Academy of Science, Guiyang 550009, China
| | - Gang Pan
- †Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085, China
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Zhang J, Shi H, Liu A, Cao Z, Hao J, Gong R. Identification of a new microcystin-degrading bacterium isolated from Lake Chaohu, China. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2015; 94:661-6. [PMID: 25820434 DOI: 10.1007/s00128-015-1531-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 03/24/2015] [Indexed: 05/20/2023]
Abstract
A microcystin-LR (MC-LR)-degrading bacterium was isolated from Lake Chaohu, a eutrophic freshwater lake containing toxic cyanobacterial blooms. Based on the analysis of 16S rDNA gene sequence and physiobiochemical characteristics, the isolated strain, most likely belongs to the genus Bacillus with the highest sequence similarity value with Bacillus nanhaiencis strain K-W39 (JQ799091.1), was named B. nanhaiencis strain JZ-2013. The strain JZ-2013 could grow on mineral salt medium supplied with MC-LR as sole carbon and nitrogen sources. The optimal temperature and pH for strain JZ-2013 growth and MC-LR biodegradation were 30°C and 8.0, respectively. The MC-LR with the initial concentration of 15 mg/L could be consumed 80 % by strain JZ-2013 within 9 days. The existence of exogenous carbon and nitrogen sources could significantly increase the removal efficiency of MC-LR. The strain JZ-2013 can efficiently removed MC-LR of low concentration in real water sample.
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Affiliation(s)
- Jian Zhang
- College of Life Science, Anhui Normal University, Wuhu, 241000, People's Republic of China
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27
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Umehara A, Komorita T, Tai A, Takahashi T, Orita R, Tsutsumi H. Short-term dynamics of cyanobacterial toxins (microcystins) following a discharge from a coastal reservoir in Isahaya Bay, Japan. MARINE POLLUTION BULLETIN 2015; 92:73-79. [PMID: 25595488 DOI: 10.1016/j.marpolbul.2014.12.053] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Revised: 12/22/2014] [Accepted: 12/30/2014] [Indexed: 06/04/2023]
Abstract
Freshwater cyanobacteria produce highly toxic substances such as microcystins (MCs), and water containing MCs is often discharged to downstream and coastal areas. We conducted field monitoring in Isahaya Bay to clarify the short-term dynamics of MCs discharged from a reservoir following a cyanobacteria bloom in the warm season. MCs were detected in the seawater of the bay (max. 0.10 μg L(-1)), and were deposited on the sea floor, with the MC content of the surface sediment increasing by approximately five times (0.11±0.077-0.53±0.15 μg kgww(-1), mean±SD) at the four stations near the reservoir drainage gate before and after the discharge. The MCs was then transported from the mouth of the bay by tidal currents during the period of the study. Therefore, the MCs were moved away from the closed water area where the cyanobacteria blooms, and spread throughout the coastal area.
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Affiliation(s)
- Akira Umehara
- Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, 3-1-100 Tsukide, Kumamoto 862-8502, Japan.
| | - Tomohiro Komorita
- Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, 3-1-100 Tsukide, Kumamoto 862-8502, Japan
| | - Akira Tai
- Faculty of Institute for Advanced Study, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan
| | - Tohru Takahashi
- Department of Medical Technology, Kumamoto Health Science University, 325 Izumi-machi, Kumamoto 861-5598, Japan
| | - Ryo Orita
- Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, 3-1-100 Tsukide, Kumamoto 862-8502, Japan
| | - Hiroaki Tsutsumi
- Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, 3-1-100 Tsukide, Kumamoto 862-8502, Japan
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Mankiewicz-Boczek J, Gągała I, Jurczak T, Jaskulska A, Pawełczyk J, Dziadek J. Bacteria homologus to Aeromonas capable of microcystin degradation. Open Life Sci 2015. [DOI: 10.1515/biol-2015-0012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
AbstractWater blooms dominated by cyanobacteria are capable of producing hepatotoxins known as microcystins. These toxins are dangerous to people and to the environment. Therefore, for a better understanding of the biological termination of this increasingly common phenomenon, bacteria with the potential to degrade cyanobacteria-derived hepatotoxins and the degradative activity of culturable bacteria were studied. Based on the presence of the mlrA gene, bacteria with a homology to the Sphingopyxis and Stenotrophomonas genera were identified as those presenting potential for microcystins degradation directly in the water samples from the Sulejów Reservoir (SU, Central Poland). However, this biodegrading potential has not been confirmed in in vitro experiments. The degrading activity of the culturable isolates from the water studied was determined in more than 30 bacterial mixes. An analysis of the biodegradation of the microcystin-LR (MC-LR) together with an analysis of the phylogenetic affiliation of bacteria demonstrated for the first time that bacteria homologous to the Aeromonas genus were able to degrade the mentioned hepatotoxin, although the mlrA gene was not amplified. The maximal removal efficiency of MC-LR was 48%. This study demonstrates a new aspect of interactions between the microcystin-containing cyanobacteria and bacteria from the Aeromonas genus.
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Affiliation(s)
- J. Mankiewicz-Boczek
- 1European Regional Centre for Ecohydrology of the Polish Academy of Sciences, Łódź, 90-364, Poland
- 2Department of Applied Ecology, Faculty of Biology and Environmental Protection, University of Lodz, Łódź, 90-237, Poland
| | - I. Gągała
- 1European Regional Centre for Ecohydrology of the Polish Academy of Sciences, Łódź, 90-364, Poland
| | - T. Jurczak
- 2Department of Applied Ecology, Faculty of Biology and Environmental Protection, University of Lodz, Łódź, 90-237, Poland
| | - A. Jaskulska
- 2Department of Applied Ecology, Faculty of Biology and Environmental Protection, University of Lodz, Łódź, 90-237, Poland
| | - J. Pawełczyk
- 3Institute for Medical Biology of the Polish Academy of Sciences, Łódź, 93-232, Poland
| | - J. Dziadek
- 3Institute for Medical Biology of the Polish Academy of Sciences, Łódź, 93-232, Poland
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29
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Corbel S, Mougin C, Bouaïcha N. Cyanobacterial toxins: modes of actions, fate in aquatic and soil ecosystems, phytotoxicity and bioaccumulation in agricultural crops. CHEMOSPHERE 2014; 96:1-15. [PMID: 24012139 DOI: 10.1016/j.chemosphere.2013.07.056] [Citation(s) in RCA: 187] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 07/15/2013] [Accepted: 07/23/2013] [Indexed: 05/26/2023]
Abstract
The occurrence of harmful cyanobacterial blooms in surface waters is often accompanied by the production of a variety of cyanotoxins. These toxins are designed to target in humans and animals specific organs on which they act: hepatotoxins (liver), neurotoxins (nervous system), cytotoxic alkaloids, and dermatotoxins (skin), but they often have important side effects too. When introduced into the soil ecosystem by spray irrigation of crops they may affect the same molecular pathways in plants having identical or similar target organs, tissues, cells or biomolecules. There are also several indications that terrestrial plants, including food crop plants, can bioaccumulate cyanotoxins and present, therefore, potential health hazards for human and animals. The number of publications concerned with phytotoxic effects of cyanotoxins on agricultural plants has increased recently. In this review, we first examine different cyanotoxins and their modes of actions in humans and mammals and occurrence of target biomolecules in vegetable organisms. Then we present environmental concentrations of cyanotoxins in freshwaters and their fate in aquatic and soil ecosystems. Finally, we highlight bioaccumulation of cyanotoxins in plants used for feed and food and its consequences on animals and human health. Overall, our review shows that the information on the effects of cyanotoxins on non-target organisms in the terrestrial environment is particularly scarce, and that there are still serious gaps in the knowledge about the fate in the soil ecosystems and phytotoxicity of these toxins.
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30
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Li H, Pan G. Enhanced and continued degradation of microcystins using microorganisms obtained through natural media. J Microbiol Methods 2013; 96:73-80. [PMID: 24246232 DOI: 10.1016/j.mimet.2013.11.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 11/05/2013] [Accepted: 11/05/2013] [Indexed: 10/26/2022]
Abstract
Microorganisms isolated through artificial media are often unsustainable in biodegrading microcystins (MCs) in natural water. Here we studied alternative approaches to isolate MCs-degrading bacteria using natural media. In comparison to two species (MS-1 and MS-2) isolated from artificial media and the failure of bacterial colonies formation using water extracts of sediment (10%, w/v), five colony species (WC-1 to WC-5) appeared using concentrated water extracts of sediment that is 10-fold enhancement of nutrient level. In the simulated biodegradation test in Lake Taihu water with continuous supply of MCs, a lag phase of 6days was required for MS-1 and M-2 to degrade 13% and 15% of the added MC-RR and MC-LR, respectively, whereas the lag phase was only 3days with approximately 44% and 31% removal of the added MC-RR and MC-LR by WC-1 to WC-5. During the continuous supply experiment, degradation of MCs by MS-1 and MS-2 stopped after 3days, while degradation of MCs by WC-1 to WC-5 lasted continuously throughout the 18day test period with 2 to 6-fold enhancement of removal rate. 16S rRNA gene sequences and phylogenetic analysis indicated the potential to amplify species of MCs-degrading bacteria when natural media were used. The results suggested that the increased adaptability of bacteria obtained through concentrated natural media was responsible for the enhanced and continued biodegradation under simulated natural water conditions.
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Affiliation(s)
- Hong Li
- Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People's Republic of China
| | - Gang Pan
- Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People's Republic of China.
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31
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Cyanobacterial toxin degrading bacteria: who are they? BIOMED RESEARCH INTERNATIONAL 2013; 2013:463894. [PMID: 23841072 PMCID: PMC3690202 DOI: 10.1155/2013/463894] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 05/21/2013] [Indexed: 11/17/2022]
Abstract
Cyanobacteria are ubiquitous in nature and are both beneficial and detrimental to humans. Benefits include being food supplements and producing bioactive compounds, like antimicrobial and anticancer substances, while their detrimental effects are evident by toxin production, causing major ecological problems at the ecosystem level. To date, there are several ways to degrade or transform these toxins by chemical methods, while the biodegradation of these compounds is understudied. In this paper, we present a meta-analysis of the currently available 16S rRNA and mlrA (microcystinase) genes diversity of isolates known to degrade cyanobacterial toxins. The available data revealed that these bacteria belong primarily to the Proteobacteria, with several strains from the sphingomonads, and one from each of the Methylobacillus and Paucibacter genera. Other strains belonged to the genera Arthrobacter, Bacillus, and Lactobacillus. By combining the ecological knowledge on the distribution, abundance, and ecophysiology of the bacteria that cooccur with toxic cyanobacterial blooms and newly developed molecular approaches, it is possible not only to discover more strains with cyanobacterial toxin degradation abilities, but also to reveal the genes associated with the degradation of these toxins.
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32
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Dziga D, Wasylewski M, Wladyka B, Nybom S, Meriluoto J. Microbial degradation of microcystins. Chem Res Toxicol 2013; 26:841-52. [PMID: 23621464 DOI: 10.1021/tx4000045] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Hepatotoxic microcystins that are produced by freshwater cyanobacteria pose a risk to public health. These compounds may be eliminated by enzymatic degradation. Here, we review the enzymatic pathways for the degradation of these hepatotoxins, some of which are newly discovered processes. The efficiencies of microcystin biodegradation pathways are documented in several papers and are compared here. Additionally, a comprehensive description of the microcystin enzymatic degradation scheme has been supplemented with a proposal for a new biodegradation pathway. Critical comments on less documented hypotheses are also included. The genetic aspects of biodegradation activity are discussed in detail. We also describe some methods that are useful for studying the biological decomposition of microcystins, including screening for microcystin degraders and detecting microcystin degradation products, with an emphasis on mass spectrometric methodology.
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Affiliation(s)
- Dariusz Dziga
- Department of Plant Physiology and Development, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
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Ho L, Sawade E, Newcombe G. Biological treatment options for cyanobacteria metabolite removal--a review. WATER RESEARCH 2012; 46:1536-1548. [PMID: 22133838 DOI: 10.1016/j.watres.2011.11.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 10/25/2011] [Accepted: 11/04/2011] [Indexed: 05/31/2023]
Abstract
The treatment of cyanobacterial metabolites can consume many resources for water authorities which can be problematic especially with the recent shift away from chemical- and energy-intensive processes towards carbon and climate neutrality. In recent times, there has been a renaissance in biological treatment, in particular, biological filtration processes, for cyanobacteria metabolite removal. This in part, is due to the advances in molecular microbiology which has assisted in further understanding the biodegradation processes of specific cyanobacteria metabolites. However, there is currently no concise portfolio which captures all the pertinent information for the biological treatment of a range of cyanobacterial metabolites. This review encapsulates all the relevant information to date in one document and provides insights into how biological treatment options can be implemented in treatment plants for optimum cyanobacterial metabolite removal.
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Affiliation(s)
- Lionel Ho
- Australian Water Quality Centre, South Australian Water Corporation, 250 Victoria Square, Adelaide, SA 5000, Australia.
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Shimizu K, Maseda H, Okano K, Itayama T, Kawauchi Y, Chen R, Utsumi M, Zhang Z, Sugiura N. How microcystin‐degrading bacteria express microcystin degradation activity. ACTA ACUST UNITED AC 2011. [DOI: 10.1111/j.1440-1770.2011.00480.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kazuya Shimizu
- Department of Life Sciences, Toyo University, Izumino Itakura Ora‐gun Gunma
| | - Hideaki Maseda
- Department of Biological Science & Technology, Institute of Technology of Science, The University of Tokushima Graduate School, Tokushima 770‐8506, Japan
| | - Kunihiro Okano
- Graduate School of Bioresource Science Akita Prefectural University, Kaidobata‐Nishi, Nakano Shimoshinjo, Akita City, Akita
| | - Tomoaki Itayama
- Research Institute for Human and Nature, Motoyama, Kamigamo, Kita‐ku, Kyoto
| | - Yukio Kawauchi
- Mitsubishi Chemical Analytech Co. Ltd., Enzo Chigasaki, Kanagawa
| | - Rongzhi Chen
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tennodai, Tsukuba, Ibaraki, Japan
| | - Motoo Utsumi
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tennodai, Tsukuba, Ibaraki, Japan
| | - Zhenya Zhang
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tennodai, Tsukuba, Ibaraki, Japan
| | - Norio Sugiura
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tennodai, Tsukuba, Ibaraki, Japan
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