Editor: Riks Laanbroek
Evaluation of taxa-specific real-time PCR, whole-cell FISH and morphotaxonomy analyses for the detection and quantification of the toxic microalgae Alexandrium minutum (Dinophyceae), Global Clade ribotype
Article first published online: 16 DEC 2008
© 2008 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved
FEMS Microbiology Ecology
Volume 67, Issue 2, pages 329–341, February 2009
How to Cite
Touzet, N., Keady, E., Raine, R. and Maher, M. (2009), Evaluation of taxa-specific real-time PCR, whole-cell FISH and morphotaxonomy analyses for the detection and quantification of the toxic microalgae Alexandrium minutum (Dinophyceae), Global Clade ribotype. FEMS Microbiology Ecology, 67: 329–341. doi: 10.1111/j.1574-6941.2008.00627.x
- Issue published online: 22 DEC 2008
- Article first published online: 16 DEC 2008
- Received 26 March 2008; revised 20 October 2008; accepted 24 October 2008.First published online 16 December 2008.
The dinoflagellate genus Alexandrium contains neurotoxin-producing species that have adversely affected the aquaculture industry in many countries. The morphological similarity between Alexandrium species has led to the development of molecular methods for the discrimination, enumeration and monitoring of toxic and nontoxic species. A quantitative real-time PCR assay (qRT-PCR) targeting the internal transcribed spacer 1-5.8S rRNA gene using hybridization probe technology was developed for the potentially toxic species Alexandrium minutum (Global Clade) (GC). The assay was specific with a detection limit of less than one cell equivalent. The assay was used to detect and quantify A. minutum (GC) in seawater samples collected during summer 2007 in Cork Harbour, Ireland. The results were compared with those obtained using whole-cell FISH (WC-FISH) and morphotaxonomy analyses. Alexandrium minutum did not reach high bloom concentrations over the sampling period (maximum of c. 6 × 104 cells L−1), and the average concentrations determined using qRT-PCR, WC-FISH and morphotaxonomy did not significantly differ in eight of nine comparisons. Regression curves showed positive relationships between the methods; WC-FISH and qRT-PCR slightly under- and overestimated, respectively, the A. minutum concentrations compared with the morphotaxonomy method. The qRT-PCR assay for A. minutum (GC) offers high-throughput sample analysis and may prove suitable for implementation in microalgae monitoring programmes and assist in population dynamics studies of the species.