Application of a quantitative PCR method for monitoring of geosmin-producing Anabaena spp. in a Japanese reservoir

Cyanobacteria blooms occur frequently in lakes and reservoirs worldwide and the blooms are often accompanied by changes in the taste and odor of the water caused by cyanobacterial metabolites, such as geosmin. The amount of geosmin in drinking water in Japan is limited legally and requires regular monitoring. The approaches for detecting geosmin are generally based on gas chromatography–mass spectrometry (GC/MS), which requires experienced personnel or sophisticated instrumentation. Here, we applied a TaqMan probe method for detecting geosmin-producing cyanobacteria, Anabaena ( Dolichospermum ) spp. in a Japanese reservoir. Quantitative PCR amplification using the methods which targeted geosmin synthase gene, worked successfully and the DNA concentrations may correspond with both the number of Anabaena spp. cells and the geosmin concentration. The tests of suitable glass microfiber filters for monitoring Anabaena spp. revealed that the samples filtered through GF/D (particle retention size 2.7 µm) yielded significantly higher concentrations of Anabaena DNA compared with the samples filtered through the GF/F and GF/A.