AdvanceWarning of Cyanobacterial Toxicity

ReportNo WSAA 108

March 1996




Arapid laboratory assay based on the inhibition of protein phosphatase activityhas been developed for the routine monitoring of the microcystin class ofcyanobacterial toxins. This test is capable of detecting toxin levels to <0.1ug microcystin-LR perlitre of water, without sample concentration. It is therefore most suitable foradvance warning of cyanobacterial toxicity.


Theassay has been extensively tested and is now available as a commercial service.Several modifications have been designed and implemented as a result of thistesting.


Usingthis assay, the existence of previously unreported endogenous cyanobacterialprotein phosphatase and proteolytic activities has been demonstrated. Theseendogenous activities may lead to underestimation of toxin concentration andmodifications to the assay have been developed.


Theeffectiveness of the assay in detecting unknown toxins or variants which cannotbe detected by any other procedure (such as HPLC) has been demonstrated.


Anon-radioactive assay has also been developed, which has the potential forfurther development as a field based test.


Irregularoccurrences of readily accessible cyanobacterial blooms in the Hunter regionthroughout this project has prevented extensive analysis of algal hot-spots andconditions predisposing to toxicity. Sampling and testing is continuing suchthat information relating to objectives (ii) and (iii) is likely to beforthcoming in subsequent years.


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