Semi-Quantitative PCR for Quantification of Hepatotoxic Cyanobacteria

Blooms of microcystin-producing cyanobacteria are a problem worldwide. Microcystin is a liver hepatotoxin commonly found in bodies of water and is produced mainly by the genus Microcystis. The aim of the present study was to develop and assess a competitive PCR method for the quantification of toxic and non-toxic Microcystis cells using the cpcBA and mcyB genes, which are respectively involved in the formation of phycocyanin and biosynthesis of microcystin. For the acquisition of competitor DNA, amplification sequences were carried out of the “cell DNA equivalent” of microcystin-producing (BCCUSP18) and non-microcystin-producing (BCCUSP03) strains of Microcystis spp. using primers described in the literature as well as others designed for the present study. The method was successfully developed, as competitor DNA was constructed and co-amplified with the target DNA. Competitive PCR proved to be useful in quantifying toxic and non-toxic cells of Microcystis spp. strains, representing a helpful methodology tool to study isolated toxin-producing cyanobacteria.