Use of environmental DNA to investigate the distribution of microcystin-producing Microcystis in Eastern Ontario
The emergence and persistence of algae blooms, comprising multiple toxicity-producing cyanobacteria genera, pose great threats to aquatic environments, to many native species, and to human health. In Ontario, cyanobacteria blooms were reported from across the province spanning 2009 to 2014, mainly occurring in Eastern Ontario as well as the southeastern part of Northern Ontario. Eastern Ontario is predicted to face increasing risk of cyanobacteria blooms in the future. microcystin-producing Microcystis is one of the dominant toxin-producing cyanobacteria genera, which presents many of the most significant challenges for water quality and public health. In this study, I develop and test a quantitative real-time polymerase chain reaction (qPCR) and environmental DNA (eDNA) approach to assess the distribution of microcystin-producing Microcystis in Eastern Ontario and estimate potential toxicity in 43 water bodies sampled in the summer of 2017. The qPCR assay was used to detect the Microcystin synthetase gene E (mcyE gene) in water samples. The limit of detection of qPCR was 3.06E+05 copies/L for mcyE. microcystin-producing Microcystis was detected in 28 out of total 43 water bodies. My research proved that a qPCR assay developed to target Microcystis gene fragments was specific and efficient for rapid detection of Microcystis and for diagnosing its toxicity.