Monitoring of saxitoxin production in lakes in Denmark by molecular, chromatographic and microscopic approaches

Autor(es)

Podduturi, Raju ^[1] ; Schluter, Louse ^[2] ; Liu, Tingting ^[3] ; Saviolo Osti, Joao Alexandre ^[4] ; Bispo Moraes, Munique de Almeida ^[5] ; Jorgensen, Niels O. G. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Copenhagen, Dept Plant & Environm Sci, Frederiksberg - Denmark

^[2] DHI Grp, Agern Alle, Horsholm - Denmark

^[3] Chinese Acad Sci, Res Ctr Ecoenvironm Sci, Beijing - Peoples R China

^[4] Univeritas UNG Univ, Postgrad Res Ctr, Guarulhos, SP - Brazil

^[5] Sao Carlos Sch Engn Univ Sao Paulo, Dept Hydraul & Sanitat, Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: HARMFUL ALGAE; v. 101, JAN 2021.
• Citações Web of Science: 4

Resumo

Diversity of phytoplankton in three eutrophic and two mesotrophic lakes in Denmark was determined by microscopic and HPLC pigment analyses to identify and quantify potential saxitoxin (STX) producing cyanobacteria. Potential dominant STX-producers were identified to the filamentous genera Dolichospermum, Cuspidothrix, Phormidium and Planktolyngbya. Presence of STX production was documented by extraction of five intracellular STXs that included (in declining concentration in the cyanobacteria) dc-neo-STX, neo-STX, dc-STX, STX and GTX. Total concentrations of the five STXs varied from 9 to 142 fg per potential STX producer, corresponding to 87 to 985 ng L-1 in the lakes. For molecular detection of the STX-producers, a quantitative PCR method was developed by design of a new robust primer set with broad coverage to target the sxtA gene that is common to all STX-producing cyanobacteria. After validation, copy numbers of the sxtA gene were determined to vary from about 10(4) (mesotrophic lakes) to 10(8) per mL (the most eutrophic lake). A moderate but significant correlation was observed between abundance of the sxtA copies and concentrations of the five intracellular STXs. The qPCR assay was found to be a rapid and robust procedure for quantification of STX producers. Saxitoxin and its analogs appeared not to cause health concerns in the lakes, but commercial fishing for pike perch in the most eutrophic lake should be monitored to test for food web accumulation of STXs. (AU)

• Processo FAPESP: 18/00394-2 - Monitoramento de cianobactérias e cianotoxinas em dois reservatórios subtropicais por PCR quantitativo em tempo real
• Beneficiário: Munique de Almeida Bispo Moraes
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado
• Processo FAPESP: 15/21191-4 - Variabilidade espaço-temporal de cianobactérias no Reservatório do Lobo (Itirapina, SP): composição da comunidade, análises moleculares e de toxinas
• Beneficiário: Munique de Almeida Bispo Moraes
• Modalidade de apoio: Bolsas no Brasil - Doutorado