Detection of Microcystin-Producing Cyanobacteria in a Reservoir by Whole Cell Quantitative PCR

Cyanobacterial blooms are of increasing concern due to their negative impacts on environment and cyanobacteria-producing cyanotoxins, which create serious threats to animal and human health. Early detection of the harmful cyanotoxin-producing cyanobacteria is vital for the water management. In this study, we compared the amplification specificity for microcystin-producing cyanobacteria with primers targeting 16S rRNA genes, phycocyanin operon, and regions of mcy gene clusters. To detect presence of microcystin-producing cyanobacteria in a drinking water sourced reservoir, whole cell PCR assay was performed to amplify partial mcyA, mcyE, and the results were compared with that of direct microscopic counts based on morphologic identification. The positive liner correlation of the Microcystis colony by microscopic counts with mcyA containing cell, which was quantified by whole cell quantitative RT-PCR assay, was further confirmed. The results indicated that the microcystin-producer in the reservoir was mainly Microcystis. Therefore, we provided a simple, rapid, sensitive and applicable method for early detection of toxic cyanobacteria.