Detection of microcystin-producing cyanobacteria in water samples using loop-mediated isothermal amplification targeting mcyB gene.

Abstract

Microcystin toxin-producing cyanobacteria are known to have harmful effects on humans and animals. We have developed a loop-mediated isothermal amplification (LAMP)-based detection method by targeting the microcystin synthetase B gene (mcyB), the gene responsible for the production of microcystin. The sensitivity of the method was found to be 1fg per reaction, and it was 1000-fold higher than the conventional PCR. The LAMP method was able to amplify the target gene with a minimum amount of dNTP (0.4mM), which further reduces the cost of reaction. The improved LAMP assay could detect the presence of the toxin-producing cyanobacteria in water samples within 2h of time, which demonstrates the rapidness of the method. Freshwater samples were screened using the developed LAMP, and seven water samples collected from lakes and a bird sanctuary tested positive for mcyB gene harboring cyanobacteria, and negative in all other drinking waters. Hence, the developed LAMP could be a possible alternative to the existing molecular methods for screening for microcystin in environmental samples with greater sensitivity.