US EPA

7420596 

Journal Article 

Monitoring of geosmin producing Anabaena circinalis using quantitative PCR 

Tsao, HW; Michinaka, A; Yen, HK; Giglio, S; Hobson, P; Monis, P; Lin, TF; , 

2014 

1 

Water Research
ISSN: 0043-1354
EISSN: 1879-2448 

PERGAMON-ELSEVIER SCIENCE LTD 

OXFORD 

49 

416-425 

English 

24176608 

10.1016/j.watres.2013.10.028 

WOS:000330601400037 

https://linkinghub.elsevier.com/retrieve/pii/S0043135413008099
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Geosmin is one of the most commonly detected off-flavor chemicals present in reservoirs and drinking water systems. Quantitative real-time PCR (qPCR) is useful for quantifying geosmin-producers by focusing on the gene encoding geosmin synthase, which is responsible for geosmin synthesis. In this study, several primers and probes were designed and evaluated to detect the geosmin synthase gene in cyanobacteria. The specificity of primer and probe sets was tested using 21 strains of laboratory cultured cyanobacteria isolated from surface waters in Australia (18) and Taiwan (2), including 6 strains with geosmin producing ability. The results showed that the primers designed in this study could successfully detect all geosmin producing strains tested. The selected primers were used in a qPCR assay, and the calibration curves were linear from 5 × 10(1) to 5 × 10(5) copies mL(-1), with a high correlation coefficient (R(2) = 0.999). This method was then applied to analyze samples taken from Myponga Reservoir, South Australia, during a cyanobacterial bloom event. The results showed good correlations between qPCR techniques and traditional methods, including cell counts determined by microscopy and geosmin concentration measured using gas chromatography (GC) coupled with a mass selective detector (MSD). Results demonstrate that qPCR could be used for tracking geosmin-producing cyanobacteria in drinking water reservoirs. The qPCR assay may provide water utilities with the ability to properly characterize a taste and odor episode and choose appropriate management and treatment options.