The Presence of Toxic and Non-Toxic Cyanobacteria in the Sediments of the Limpopo River Basin: Implications for Human Health
The presence of harmful algal blooms (HABs) and cyanotoxins in drinking water sources poses a great threat to human health. The current study employed molecular techniques to determine the occurrence of non-toxic and toxic cyanobacteria species in the Limpopo River basin based on the phylogenetic an...
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| Format: | Article |
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MDPI AG
2018-07-01
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| Series: | Toxins |
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| Online Access: | http://www.mdpi.com/2072-6651/10/7/269 |
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| author | Murendeni Magonono Paul Johan Oberholster Shonhai Addmore Makumire Stanley Jabulani Ray Gumbo |
| author_facet | Murendeni Magonono Paul Johan Oberholster Shonhai Addmore Makumire Stanley Jabulani Ray Gumbo |
| author_sort | Murendeni Magonono |
| collection | DOAJ |
| description | The presence of harmful algal blooms (HABs) and cyanotoxins in drinking water sources poses a great threat to human health. The current study employed molecular techniques to determine the occurrence of non-toxic and toxic cyanobacteria species in the Limpopo River basin based on the phylogenetic analysis of the 16S rRNA gene. Bottom sediment samples were collected from selected rivers: Limpopo, Crocodile, Mokolo, Mogalakwena, Nzhelele, Lephalale, Sand Rivers (South Africa); Notwane (Botswana); and Shashe River and Mzingwane River (Zimbabwe). A physical-chemical analysis of the bottom sediments showed the availability of nutrients, nitrates and phosphates, in excess of 0.5 mg/L, in most of the river sediments, while alkalinity, pH and salinity were in excess of 500 mg/L. The FlowCam showed the dominant cyanobacteria species that were identified from the sediment samples, and these were the Microcystis species, followed by Raphidiopsis raciborskii, Phormidium and Planktothrix species. The latter species were also confirmed by molecular techniques. Nevertheless, two samples showed an amplification of the cylindrospermopsin polyketide synthetase gene (S3 and S9), while the other two samples showed an amplification for the microcystin/nodularin synthetase genes (S8 and S13). Thus, these findings may imply the presence of toxic cyanobacteria species in the studied river sediments. The presence of cyanobacteria may be hazardous to humans because rural communities and farmers abstract water from the Limpopo river catchment for human consumption, livestock and wildlife watering and irrigation. |
| first_indexed | 2024-04-11T12:19:27Z |
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| id | doaj.art-8bff51235a41405eb803a1e00513e567 |
| institution | Directory Open Access Journal |
| issn | 2072-6651 |
| language | English |
| last_indexed | 2024-04-11T12:19:27Z |
| publishDate | 2018-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Toxins |
| spelling | doaj.art-8bff51235a41405eb803a1e00513e5672022-12-22T04:24:09ZengMDPI AGToxins2072-66512018-07-0110726910.3390/toxins10070269toxins10070269The Presence of Toxic and Non-Toxic Cyanobacteria in the Sediments of the Limpopo River Basin: Implications for Human HealthMurendeni Magonono0Paul Johan Oberholster1Shonhai Addmore2Makumire Stanley3Jabulani Ray Gumbo4Department of Hydrology and Water Resources, School of Environmental Sciences, University of Venda, Thohoyandou 0950, South AfricaCouncil for Scientific and Industrial Research, Natural Resources and the Environment, Stellenbosch 7600, South AfricaDepartment of Biochemistry, School of Mathematical and Natural Sciences, University of Venda, Thohoyandou 0950, South AfricaDepartment of Biochemistry, School of Mathematical and Natural Sciences, University of Venda, Thohoyandou 0950, South AfricaDepartment of Hydrology and Water Resources, School of Environmental Sciences, University of Venda, Thohoyandou 0950, South AfricaThe presence of harmful algal blooms (HABs) and cyanotoxins in drinking water sources poses a great threat to human health. The current study employed molecular techniques to determine the occurrence of non-toxic and toxic cyanobacteria species in the Limpopo River basin based on the phylogenetic analysis of the 16S rRNA gene. Bottom sediment samples were collected from selected rivers: Limpopo, Crocodile, Mokolo, Mogalakwena, Nzhelele, Lephalale, Sand Rivers (South Africa); Notwane (Botswana); and Shashe River and Mzingwane River (Zimbabwe). A physical-chemical analysis of the bottom sediments showed the availability of nutrients, nitrates and phosphates, in excess of 0.5 mg/L, in most of the river sediments, while alkalinity, pH and salinity were in excess of 500 mg/L. The FlowCam showed the dominant cyanobacteria species that were identified from the sediment samples, and these were the Microcystis species, followed by Raphidiopsis raciborskii, Phormidium and Planktothrix species. The latter species were also confirmed by molecular techniques. Nevertheless, two samples showed an amplification of the cylindrospermopsin polyketide synthetase gene (S3 and S9), while the other two samples showed an amplification for the microcystin/nodularin synthetase genes (S8 and S13). Thus, these findings may imply the presence of toxic cyanobacteria species in the studied river sediments. The presence of cyanobacteria may be hazardous to humans because rural communities and farmers abstract water from the Limpopo river catchment for human consumption, livestock and wildlife watering and irrigation.http://www.mdpi.com/2072-6651/10/7/269cyanobacteriacyanotoxinsnutrient enrichmentakinetesharmful algal bloomsPCRphylogenetic analyses |
| spellingShingle | Murendeni Magonono Paul Johan Oberholster Shonhai Addmore Makumire Stanley Jabulani Ray Gumbo The Presence of Toxic and Non-Toxic Cyanobacteria in the Sediments of the Limpopo River Basin: Implications for Human Health Toxins cyanobacteria cyanotoxins nutrient enrichment akinetes harmful algal blooms PCR phylogenetic analyses |
| title | The Presence of Toxic and Non-Toxic Cyanobacteria in the Sediments of the Limpopo River Basin: Implications for Human Health |
| title_full | The Presence of Toxic and Non-Toxic Cyanobacteria in the Sediments of the Limpopo River Basin: Implications for Human Health |
| title_fullStr | The Presence of Toxic and Non-Toxic Cyanobacteria in the Sediments of the Limpopo River Basin: Implications for Human Health |
| title_full_unstemmed | The Presence of Toxic and Non-Toxic Cyanobacteria in the Sediments of the Limpopo River Basin: Implications for Human Health |
| title_short | The Presence of Toxic and Non-Toxic Cyanobacteria in the Sediments of the Limpopo River Basin: Implications for Human Health |
| title_sort | presence of toxic and non toxic cyanobacteria in the sediments of the limpopo river basin implications for human health |
| topic | cyanobacteria cyanotoxins nutrient enrichment akinetes harmful algal blooms PCR phylogenetic analyses |
| url | http://www.mdpi.com/2072-6651/10/7/269 |
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