Gobry Josephine J, Bachwenkizi Hilda S, Kimambo Offoro N, Ngassapa Faustin N, Kilulya Kessy F
Department of Chemistry, College of Natural and Applied Science, University of Dar es Salaam, P.O. Box 35061, Dar es Salaam, Tanzania.
Department of Water Resources, Water Institute, P.O. Box 35059, Dar es Salaam, Tanzania.
J Toxicol. 2023 Oct 16;2023:5532962. doi: 10.1155/2023/5532962. eCollection 2023.
Harmful algal blooms (HABs) pose a significant threat to aquatic ecosystems and human health due to the production of toxins. The identification and quantification of these toxins are crucial for water quality management decisions. This study used DNA analysis (PCR techniques) to identify toxin-producing strains and liquid-chromatography-tandem mass spectrometry (LC-MS/MS) to quantify microcystins in samples from Mindu and Nyumba ya Mungu Dams in Tanzania. The results showed that HABs were detected in both dams. The BLAST results revealed that the 16S gene sequences of uncultured samples were very similar to an , , , and . Sequences of the cultured samples were most similar to , , , and . Further analyses showed that the nucleotide sequence similarity of uncultured isolates from this study and those from the GenBank ranged from 85 to 100%. For cultured isolates from this study and others from the GenBank, nucleotide identity ranged from 81 to 100%. The molecular identification of confirmed the presence of HABs in both Mindu and Nyumba ya Mungu Dams in Tanzania. At Mindu Dam, the mean concentrations (± standard deviation) of microcystin-LR, -RR, and -YR were 1.08 ± 0.749 ppm, 0.120 ± 0.0211 ppm, and 1.37 ± 0.862 ppm, respectively. Similarly, at Nyumba ya Mungu Dam, the concentrations of microcystin-LR, -RR, and -YR were 1.07 ± 0.499 ppm, 0.124 ± 0.0224 ppm, and 0.961 ± 0.408 ppm, respectively. This paper represents the first application of PCR and LC-MS/MS to study microcystins in small freshwater reservoirs in Tanzania. This study confirms the presence of toxin-producing strains of in both dams and also provides evidence of the occurrence of microcystins from these strains. These findings contribute in improving the monitoring of HABs contamination and their potential impact on water quality in Tanzanian reservoirs.
有害藻华（HABs）由于会产生毒素，对水生生态系统和人类健康构成重大威胁。这些毒素的鉴定和定量对于水质管理决策至关重要。本研究使用DNA分析（PCR技术）来鉴定产毒素菌株，并使用液相色谱-串联质谱法（LC-MS/MS）对坦桑尼亚明杜大坝和纽姆巴亚蒙古大坝样本中的微囊藻毒素进行定量。结果表明，两座大坝均检测到有害藻华。BLAST结果显示，未培养样本的16S基因序列与[具体名称1]、[具体名称2]、[具体名称3]和[具体名称4]非常相似。培养样本的序列与[具体名称5]、[具体名称6]、[具体名称7]和[具体名称8]最为相似。进一步分析表明，本研究中未培养分离株与GenBank中分离株的核苷酸序列相似性在85%至100%之间。对于本研究中的培养分离株与GenBank中的其他分离株，核苷酸同一性在81%至100%之间。[具体名称]的分子鉴定证实了坦桑尼亚明杜大坝和纽姆巴亚蒙古大坝中均存在有害藻华。在明杜大坝，微囊藻毒素-LR、-RR和-YR的平均浓度（±标准差）分别为1.08±0.749 ppm、0.120±0.0211 ppm和1.37±0.862 ppm。同样，在纽姆巴亚蒙古大坝，微囊藻毒素-LR、-RR和-YR的浓度分别为1.07±0.499 ppm、0.124±0.0224 ppm和0.961±0.408 ppm。本文首次应用PCR和LC-MS/MS研究坦桑尼亚小型淡水水库中的微囊藻毒素。本研究证实了两座大坝中均存在产毒素的[具体名称]菌株，并提供了这些菌株产生微囊藻毒素的证据。这些发现有助于改进对坦桑尼亚水库中有害藻华污染及其对水质潜在影响的监测。
