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sxtA-Based Quantitative Molecular Assay To Identify Saxitoxin-Producing Harmful Algal Blooms in Marine Waters


Murray, SA and Wiese, M and Stuken, A and Brett, S and Kellmann, R and Hallegraeff, GM and Neilan, BA, sxtA-Based Quantitative Molecular Assay To Identify Saxitoxin-Producing Harmful Algal Blooms in Marine Waters, Applied and Environmental Microbiology, 77, (19) pp. 7050-7057. ISSN 0099-2240 (2011) [Refereed Article]

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Copyright 2011 American Society for Microbiology

DOI: doi:10.1128/AEM.05308-11


The recent identification of genes involved in the production of the potent neurotoxin and keystone metabolite saxitoxin (STX) in marine eukaryotic phytoplankton has allowed us for the first time to develop molecular genetic methods to investigate the chemical ecology of harmful algal blooms in situ. We present a novel method for detecting and quantifying the potential for STX production in marine environmental samples. Our assay detects a domain of the gene sxtA that encodes a unique enzyme putatively involved in the sxt pathway in marine dinoflagellates, sxtA4. A product of the correct size was recovered from nine strains of four species of STX-producing Alexandrium and Gymnodinium catenatum and was not detected in the non-STX-producing Alexandrium species, other dinoflagellate cultures, or an environmental sample that did not contain known STX-producing species. However, sxtA4 was also detected in the non-STX-producing strain of Alexandrium tamarense, Tasmanian ribotype. We investigated the copy number of sxtA4 in three strains of Alexandrium catenella and found it to be relatively constant among strains. Using our novel method, we detected and quantified sxtA4 in three environmental blooms of Alexandrium catenella that led to STX uptake in oysters. We conclude that this method shows promise as an accurate, fast, and cost-effective means of quantifying the potential for STX production in marine samples and will be useful for biological oceanographic research and harmful algal bloom monitoring.

Item Details

Item Type:Refereed Article
Keywords:toxic dinoflagellate probe
Research Division:Biological Sciences
Research Group:Plant biology
Research Field:Phycology (incl. marine grasses)
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - aquaculture
Objective Field:Fisheries - aquaculture not elsewhere classified
UTAS Author:Hallegraeff, GM (Professor Gustaaf Hallegraeff)
ID Code:76300
Year Published:2011
Funding Support:Australian Research Council (LP0776759)
Web of Science® Times Cited:87
Deposited By:IMAS Research and Education Centre
Deposited On:2012-03-04
Last Modified:2017-10-31

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