Effective Early Treatment of <i>Microcystis</i> Exponential Growth and Microcystin Production with Hydrogen Peroxide and Hydroxyapatite
Mitigating cyanotoxin production is essential to protecting aquatic ecosystems and public health. However, current harmful cyanobacterial bloom (HCB) control strategies have significant shortcomings. Because predicting HCBs is difficult, current HCB control strategies are employed when heavy HCBs ha...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-12-01
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| Series: | Toxins |
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| Online Access: | https://www.mdpi.com/2072-6651/15/1/3 |
| _version_ | 1797436655309684736 |
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| author | Ian Struewing Nathan Sienkiewicz Chiqian Zhang Nicholas Dugan Jingrang Lu |
| author_facet | Ian Struewing Nathan Sienkiewicz Chiqian Zhang Nicholas Dugan Jingrang Lu |
| author_sort | Ian Struewing |
| collection | DOAJ |
| description | Mitigating cyanotoxin production is essential to protecting aquatic ecosystems and public health. However, current harmful cyanobacterial bloom (HCB) control strategies have significant shortcomings. Because predicting HCBs is difficult, current HCB control strategies are employed when heavy HCBs have already occurred. Our pilot study developed an effective HCB prediction approach that is employed before exponential cyanobacterial growth and massive cyanotoxin production can occur. We used a quantitative polymerase chain reaction (qPCR) assay targeting the toxin-encoding gene <i>mcyA</i> to signal the timing of treatment. When control measures were applied at an early growth stage or one week before the exponential growth of <i>Microcystis aeruginosa</i> (predicted by qPCR signals), both hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) and the adsorbent hydroxyapatite (HAP) effectively stopped <i>M. aeruginosa</i> growth and microcystin (MC) production. Treatment with either H<sub>2</sub>O<sub>2</sub> (10 mg·L<sup>−1</sup>) or HAP (40 µm particles at 2.5 g·L<sup>−1</sup>) significantly reduced both <i>mcyA</i> gene copies and MC levels compared with the control in a dose-dependent manner. While both treatments reduced MC levels similarly, HAP showed a greater ability to reduce <i>mcyA</i> gene abundance. Under laboratory culture conditions, H<sub>2</sub>O<sub>2</sub> and HAP also prevented MC production when applied at the early stages of the bloom when <i>mcyA</i> gene abundance was below 10<sup>5</sup> copies·mL<sup>−1</sup>. |
| first_indexed | 2024-03-09T11:05:45Z |
| format | Article |
| id | doaj.art-05c7bf96e45649ee8796efe3d8d79382 |
| institution | Directory Open Access Journal |
| issn | 2072-6651 |
| language | English |
| last_indexed | 2024-03-09T11:05:45Z |
| publishDate | 2022-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Toxins |
| spelling | doaj.art-05c7bf96e45649ee8796efe3d8d793822023-12-01T00:56:17ZengMDPI AGToxins2072-66512022-12-01151310.3390/toxins15010003Effective Early Treatment of <i>Microcystis</i> Exponential Growth and Microcystin Production with Hydrogen Peroxide and HydroxyapatiteIan Struewing0Nathan Sienkiewicz1Chiqian Zhang2Nicholas Dugan3Jingrang Lu4Office of Research and Development, United States Environmental Protection Agency, Cincinnati, OH 45268, USAOffice of Research and Development, United States Environmental Protection Agency, Cincinnati, OH 45268, USADepartment of Civil and Environmental Engineering, Southern University and A&M College, Baton Rouge, LA 70813, USAOffice of Research and Development, United States Environmental Protection Agency, Cincinnati, OH 45268, USAOffice of Research and Development, United States Environmental Protection Agency, Cincinnati, OH 45268, USAMitigating cyanotoxin production is essential to protecting aquatic ecosystems and public health. However, current harmful cyanobacterial bloom (HCB) control strategies have significant shortcomings. Because predicting HCBs is difficult, current HCB control strategies are employed when heavy HCBs have already occurred. Our pilot study developed an effective HCB prediction approach that is employed before exponential cyanobacterial growth and massive cyanotoxin production can occur. We used a quantitative polymerase chain reaction (qPCR) assay targeting the toxin-encoding gene <i>mcyA</i> to signal the timing of treatment. When control measures were applied at an early growth stage or one week before the exponential growth of <i>Microcystis aeruginosa</i> (predicted by qPCR signals), both hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) and the adsorbent hydroxyapatite (HAP) effectively stopped <i>M. aeruginosa</i> growth and microcystin (MC) production. Treatment with either H<sub>2</sub>O<sub>2</sub> (10 mg·L<sup>−1</sup>) or HAP (40 µm particles at 2.5 g·L<sup>−1</sup>) significantly reduced both <i>mcyA</i> gene copies and MC levels compared with the control in a dose-dependent manner. While both treatments reduced MC levels similarly, HAP showed a greater ability to reduce <i>mcyA</i> gene abundance. Under laboratory culture conditions, H<sub>2</sub>O<sub>2</sub> and HAP also prevented MC production when applied at the early stages of the bloom when <i>mcyA</i> gene abundance was below 10<sup>5</sup> copies·mL<sup>−1</sup>.https://www.mdpi.com/2072-6651/15/1/3adsorptionH<sub>2</sub>O<sub>2</sub>harmful cyanobacterial bloomscyanotoxinssurface water<i>Microcystis aeruginosa</i> |
| spellingShingle | Ian Struewing Nathan Sienkiewicz Chiqian Zhang Nicholas Dugan Jingrang Lu Effective Early Treatment of <i>Microcystis</i> Exponential Growth and Microcystin Production with Hydrogen Peroxide and Hydroxyapatite Toxins adsorption H<sub>2</sub>O<sub>2</sub> harmful cyanobacterial blooms cyanotoxins surface water <i>Microcystis aeruginosa</i> |
| title | Effective Early Treatment of <i>Microcystis</i> Exponential Growth and Microcystin Production with Hydrogen Peroxide and Hydroxyapatite |
| title_full | Effective Early Treatment of <i>Microcystis</i> Exponential Growth and Microcystin Production with Hydrogen Peroxide and Hydroxyapatite |
| title_fullStr | Effective Early Treatment of <i>Microcystis</i> Exponential Growth and Microcystin Production with Hydrogen Peroxide and Hydroxyapatite |
| title_full_unstemmed | Effective Early Treatment of <i>Microcystis</i> Exponential Growth and Microcystin Production with Hydrogen Peroxide and Hydroxyapatite |
| title_short | Effective Early Treatment of <i>Microcystis</i> Exponential Growth and Microcystin Production with Hydrogen Peroxide and Hydroxyapatite |
| title_sort | effective early treatment of i microcystis i exponential growth and microcystin production with hydrogen peroxide and hydroxyapatite |
| topic | adsorption H<sub>2</sub>O<sub>2</sub> harmful cyanobacterial blooms cyanotoxins surface water <i>Microcystis aeruginosa</i> |
| url | https://www.mdpi.com/2072-6651/15/1/3 |
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