| Title | Cyanobacterial biodiversity of semiarid public drinking water supply reservoirs assessed via next-generation DNA sequencing technology |
|---|---|
| Author | Adriana Sturion Lorenzi1,2, Mathias Ahii Chia1,3, Fabyano Alvares Cardoso Lopes2,4, Genivaldo Gueiros Z. Silva2, Robert A. Edwards2,5, and Maria do Carmo Bittencourt-Oliveira1* |
| Address | 1Laboratory of Cyanobacteria, Department of Biological Sciences, Luiz de Queiroz College of Agriculture, University of São Paulo (USP), Piracicaba, SP, Brazil, 2Computational Science Research Center, San Diego State University, San Diego, California, USA, 3School of Marine and Atmospheric Sciences, Stony Brook University, Southampton Campus, New York, USA, 4Laboratory of Enzymology, Department of Cell Biology, University of Brasília (UNB), Brasília, DF, Brazil, 5Department of Computer Science, San Diego State University, San Diego, California, USA |
| Bibliography | Journal of Microbiology, 57(6),450–460, 2019, |
| DOI | 10.1007/s12275-019-8349-7 |
| Key Words | cyanotoxins, genotypic composition, NGS, public water supply, water quality |
| Abstract | Next-generation DNA sequencing technology was applied to generate molecular data from semiarid reservoirs during well-defined seasons. Target sequences of 16S-23S rRNA ITS and cpcBA-IGS were used to reveal the taxonomic groups of cyanobacteria present in the samples, and genes coding for cyanotoxins such as microcystins (mcyE), saxitoxins (sxtA), and cylindrospermopsins (cyrJ) were investigated. The presence of saxitoxins in the environmental samples was evaluated using ELISA kit. Taxonomic analyses of high-throughput DNA sequencing data showed the dominance of the genus Microcystis in Mundaú reservoir. Furthermore, it was the most abundant genus in the dry season in Ingazeira reservoir. In the rainy season, 16S-23S rRNA ITS analysis revealed that Cylindrospermopsis raciborskii comprised 46.8% of the cyanobacterial community in Ingazeira reservoir, while the cpcBAIGS region revealed that C. raciborskii (31.8%) was the most abundant taxon followed by Sphaerospermopsis aphanizomenoides (17.3%) and Planktothrix zahidii (16.6%). Despite the presence of other potential toxin-producing genera, the detected sxtA gene belonged to C. raciborskii, while the mcyE gene belonged to Microcystis in both reservoirs. The detected mcyE gene had good correlation with MC content, while the amplification of the sxtA gene was related to the presence of STX. The cyrJ gene was not detected in these samples. Using DNA analyses, our results showed that the cyanobacterial composition of Mundaú reservoir was similar in successive dry seasons, and it varied between seasons in Ingazeira reservoir. In addition, our data suggest that some biases of analysis influenced the cyanobacterial communities seen in the NGS output of Ingazeira reservoir. |