Monitoring of cyanobacteria and cyanotoxins in two subtropical reservoirs by real-time quantitative PCR

• Grant number: 18/00394-2
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: May 02, 2018
• End date: November 01, 2018
• Field of knowledge: Engineering - Sanitary Engineering - Environmental Sanitation
• Principal Investigator: Maria do Carmo Calijuri
• Grantee: Munique de Almeida Bispo Moraes
• Supervisor: Niels Ole Gerslev Jørgensen
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Institution abroad: University of Copenhagen, Copenhagen, Denmark
• Associated to the scholarship: 15/21191-4 - Spatio-temporal variability of cyanobacteria in Lobo Reservoir (Itirapina, SP): community composition, molecular and toxins analysis, BP.DR

Abstract

Cyanobacteria are known as cyanotoxin producers, and the occurrence of potentially toxic blooms in public water supply reservoirs has been more frequently observed due to eutrophication. Among the cyanotoxins produced by cyanobacteria, microcystin and saxitoxin are highlighted. These metabolites are biosynthesized by two gene groups known as mcy and sxt, respectively. The detection of these genes through real-time polymerase chain reaction (qPCR) allows for the grouping of toxic and non-toxic strains, otherwise impossible if done only by morphology. Therefore, the goal of this project is to investigate the occurrence of potentially cyanotoxin producing cyanobacteria in two subtropical reservoirs, Lobo and Itupararanga, via amplification of 16S rRNA, mcyA and sxtA genes by qPCR. Four samplings were performed during the course of a year in the riverine and dam zones of both reservoirs, in two depths (surface and lower boundary of the photic zone). After the total DNA extraction and the integrity and concentration verification, the amplification reactions of the target genes will be executed with the use of primers. The standard curves will be established by matching the target fragments' concentrations with the threshold cycle (the PCR cycle step in which the fluorescence surpasses an established threshold level) for the three analyzed genes. With the conclusion of the qPCR analysis, the obtained results will be compared to biological and physical-chemical water variables such as cyanobacteria abundance, concentration of cyanotoxins, water temperature and TN:TP ratio to comprehend the cyanobacteria and cyanotoxins occurrence in both studied environments. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MORAES, MUNIQUE DE ALMEIDA BISPO; RODRIGUES, RAPHAELLA DE ABREU MAGALHAES; PODDUTURI, RAJU; JORGENSEN, NIELS OLE GERSLEV; CALIJURI, MARIA DO CARMO. Prediction of Cyanotoxin Episodes in Freshwater: A Case Study on Microcystin and Saxitoxin in the Lobo Reservoir, Sao Paulo State, Brazil. ENVIRONMENTS, v. 10, n. 8, p. 16-pg., 2023-08-01. (16/09405-1, 18/00394-2, 15/21191-4)

MORAES, MUNIQUE A. B.; RODRIGUES, RAPHAELLA A. M.; SCHLUTER, LOUISE; PODDUTURI, RAJU; JORGENSEN, NIELS O. G.; CALIJURI, MARIA C.. Influence of Environmental Factors on Occurrence of Cyanobacteria and Abundance of Saxitoxin-Producing Cyanobacteria in a Subtropical Drinking Water Reservoir in Brazil. WATER, v. 13, n. 12, JUN 2021. (15/21191-4, 16/09405-1, 18/00394-2)

PODDUTURI, RAJU; SCHLUTER, LOUSE; LIU, TINGTING; SAVIOLO OSTI, JOAO ALEXANDRE; BISPO MORAES, MUNIQUE DE ALMEIDA; JORGENSEN, NIELS O. G.. Monitoring of saxitoxin production in lakes in Denmark by molecular, chromatographic and microscopic approaches. HARMFUL ALGAE, v. 101, JAN 2021. (18/00394-2, 15/21191-4)