Simultaneous Microcystin Degradation and <i>Microcystis aeruginosa</i> Inhibition with the Single Enzyme Microcystinase A

Liu, Honglin; Guo, Xiaoliang; Liu, Lei; Yan, Mingyue; Li, Jiahui; Hou, Shuyan; Wan, Jian; Feng, Lingling

doi:10.1021/acs.est.0c02155

Cited by 54 publications

(56 citation statements)

References 43 publications

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“…It was noteworthy that a single Acinetobacter sp. or a single enzyme (Microcystinase A) was identified to degrade MC-LR and inhibit growth of Microcystis aeruginosa simultaneously [ 14 , 34 ]. The specific distribution of lytic-cyanobacteria bacteria and MC-LR-degrading bacteria accounts for the vegetable-dependent MC-LR degradation in soils of ACM treatments.…”

Section: Resultsmentioning

confidence: 99%

“…Concentrations of MCs in waters are normally lower than 100 μg/L, but sometimes could be up to thousands of microgramme per litre, relying on environmental conditions and occurrence of MCs-producing cyanobacteria [ 8 , 12 ]. MCs in water can enter agricultural soils and show relatively high stability, because their cyclical heptapeptide structure is resistant to non-specific enzyme degradation, pH changes, and high temperature [ 13 , 14 , 15 ]. There is thus a great possibility that agricultural soils in the regions with frequent CBs outbreaks can be heavily polluted by MCs [ 12 , 16 , 17 ].…”

Section: Introductionmentioning

confidence: 99%

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Bioaccumulation and Phytotoxicity and Human Health Risk from Microcystin-LR under Various Treatments: A Pot Study

Xiang

Wang

et al. 2020

Toxins

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Microcystin-LR (MC-LR) is prevalent in water and can be translocated into soil-crop ecosystem via irrigation, overflow (pollution accident), and cyanobacterial manure applications, threatening agricultural production and human health. However, the effects of various input pathways on the bioaccumulation and toxicity of MCs in terrestrial plants have been hardly reported so far. In the present study, pot experiments were performed to compare the bioaccumulation, toxicity, and health risk of MC-LR as well as its degradation in soils among various treatments with the same total amount of added MC-LR (150 μg/kg). The treatments included irrigation with polluted water (IPW), cultivation with polluted soil (CPS), and application of cyanobacterial manure (ACM). Three common leaf-vegetables in southern China were used in the pot experiments, including Ipomoea batatas L., Brassica juncea L., and Brassica alboglabra L. All leaf vegetables could bioaccumulate MC-LR under the three treatments, with much higher MC-LR bioaccumulation, especially root bioconcentration observed in ACM treatment than IPW and CPS treatments. An opposite trend in MC-LR degradation in soils of these treatments indicated that ACM could limit MC-LR degradation in soils and thus promote its bioaccumulation in the vegetables. MC-LR bioaccumulation could cause toxicity to the vegetables, with the highest toxic effects observed in ACM treatment. Similarly, bioaccumulation of MC-LR in the edible parts of the leaf-vegetables posed 1.1~4.8 fold higher human health risks in ACM treatment than in IPW and CPS treatments. The findings of this study highlighted a great concern on applications of cyanobacterial manure.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Bioaccumulation and Phytotoxicity and Human Health Risk from Microcystin-LR under Various Treatments: A Pot Study

Xiang

Wang

et al. 2020

Toxins

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“…However, this work mostly emphasized the effects of bacteria that degrade MCs. Microorganisms used in biological treatments may also carry potential risks (e.g., biological invasion) (Liu et al, 2020). Less information is available on the effects of a secreted substance (e.g., active enzyme) on the degradation of MCs.…”

Section: Discussionmentioning

confidence: 99%

“…MC-LTH1 (Yang et al, 2014). However, there are potential risks that these microorganisms used in treating MCs may become ecologically dominant or secrete unknown toxic substances into the water (Liu et al, 2020). Therefore, safe and effective treatment against MCs is still a great challenge.…”

Section: Introductionmentioning

confidence: 99%

Characterization and Mechanism of Linearized-Microcystinase Involved in Bacterial Degradation of Microcystins

et al. 2021

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Microcystins (MCs) are extremely hazardous to the ecological environment and public health. How to control and remove MCs is an unsolved problem all over the world. Some microbes and their enzymes are thought to be effective in degrading MCs. Microcystinase can linearize microcystin-leucine-arginine (MC-LR) via a specific locus. However, linearized MC-LR is also very toxic and needs to be removed. How linearized MC-LR was metabolized by linearized-microcystinase, especially how linearized-microcystinase binds to linearized MC-LR, has not been defined. A combination of in vitro experiments and computer simulation was applied to explore the characterization and molecular mechanisms for linearized MC-LR degraded by linearized-microcystinase. The purified linearized-microcystinase was obtained by recombinant Escherichia coli overexpressing. The concentration of linearized MC-LR was detected by high-performance liquid chromatography, and linearized MC-LR degradation products were analyzed by the mass spectrometer. Homology modeling was used to predict the structure of the linearized-microcystinase. Molecular docking techniques on the computer were used to simulate the binding sites of linearized-microcystinase and linearized MC-LR. The purified linearized-microcystinase was obtained successfully. The linearized-microcystinase degraded linearized MC-LR to tetrapeptide efficiently. The second structure of linearized-microcystinase consisted of many alpha-helices, beta-strands, and colis. Linearized-microcystinase interacted the linearized MC-LR with hydrogen bond, hydrophobic interaction, electrostatic forces, and the Van der Waals force. This study firstly reveals the characterization and specific enzymatic mechanism of linearized-microcystinase for catalyzing linearized MC-LR. These findings encourage the application of MC-degrading engineering bacteria and build a great technique for MC-LR biodegradation in environmental engineering.

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“…The overgrowth of harmful algae cause deterioration of water quality and emit an unpleasant smell, leading to the loss of recreational and property values of aquatic ecosystems (Zhang et al 2021). In cyano-HABs, several cyanobacterial genera such as Anabaena, Microcystis, Nostoc and Planktothrix can produce toxic secondary metabolites (Dziga et al 2013), which can inhibit the growth of other taxa and increase the competitive and defensive abilities (Liu et al 2020). The existence of these toxins in waterbodies for recreation, drinking water and irrigation can pose serious human health risks and thus become an increasingly concerned public health topic (Preece et al 2021).…”

Section: Introductionmentioning

confidence: 99%

Microcystin-leucine arginine blocks vasculogenesis and angiogenesis through impairing cytoskeleton and impeding endothelial cell migration by downregulating integrin-mediated Rho/ROCK signaling pathway

Wang

Chen

Zhang

et al. 2021

Environ Sci Pollut Res

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The main characteristic of eutrophication is cyanobacteria harmful algae blooms. Microcystin-leucine arginine (MC-LR) is considered to be the most toxic and most commonly secondary metabolite produced by cyanobacteria. It has been reported that MC-LR had potential vascular toxicity. However, the mechanism that MC-LR induced vascular toxicity is very limited and remain to be clari ed. The aim of this study was to evaluate the toxic hazard towards the vasculogenesis and angiogenesis of MC-LR. Its effects on vasculogenesis, sprouting angiogenesis and endothelial cell tube formation were studied. The study showed that MC-LR exposure blocked vasculogenesis in zebra sh embryos, sprouting angiogenesis from rat aorta and tube formation of human umbilical vein endothelial cells (HUVECs). In addition, MC-LR exposure also induced the disruption of cytoskeletal structures and markedly inhibited endothelial cells (ECs) migration from caudal hematopoietic tissue in zebra sh and HUVEC migration.Western blot analysis showed that MC-LR exposure down-regulated the expressions of integrin β1, FAK, Rho and ROCK. Combined with these results, MC-LR could induce disruption of cytoskeleton via downregulating integrin-mediated FAK/ROCK signaling pathway, leading to the inhibition of ECs migration, which nally blocked vasculogenesis and angiogenesis.

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Simultaneous Microcystin Degradation and Microcystis aeruginosa Inhibition with the Single Enzyme Microcystinase A

Cited by 54 publications

References 43 publications

Bioaccumulation and Phytotoxicity and Human Health Risk from Microcystin-LR under Various Treatments: A Pot Study

Bioaccumulation and Phytotoxicity and Human Health Risk from Microcystin-LR under Various Treatments: A Pot Study

Characterization and Mechanism of Linearized-Microcystinase Involved in Bacterial Degradation of Microcystins

Microcystin-leucine arginine blocks vasculogenesis and angiogenesis through impairing cytoskeleton and impeding endothelial cell migration by downregulating integrin-mediated Rho/ROCK signaling pathway

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