Emerging high throughput analyses of cyanobacterial toxins and toxic cyanobacteria

Abstract

The common occurrence of toxic cyanobacteria causes problems for health of animals and human beings. More research and good monitoring systems are needed to protect water users. It is important to have rapid, reliable and accurate analysis i.e. high throughput methods to identify the toxins as well as toxin producers in the environment. Excellent methods, such as ELISA already exist to analyse cyanobacterial hepatotoxins and saxitoxins, and PPIA for microcystins and nodularins. The LC/MS method can be fast in identifying the toxicants in the samples. Further development of this area should resolve the problems with sampling and sample preparation, which still are the bottlenecks of rapid analyses. In addition, the availability of reliable reference materials and standards should be resolved. Molecular detection methods are now routine in clinical and criminal laboratories and may also become important in environmental diagnostics. One prerequisite for the development of molecular analysis is that pure cultures of the producer organisms are available for identification of the biosynthetic genes responsible for toxin production and for proper testing of the diagnostic methods. Good methods are already available for the microcystin and nodularin-producing cyanobacteria such as conventional PCR, quantitative real-time PCR and microarrays/DNA chips. The DNA-chip technology offers an attractive monitoring system for toxic and non-toxic cyanobacteria. Only with these new technologies (PCR + DNA-chips) will we be able to study toxic cyanobacteria populations in situ and the effects of environmental factors on the occurrence and proliferation of especially toxic cyanobacteria. This is likely to yield important information for mitigation purposes. Further development of these methods should include all cyanobacterial biodiversity, including all toxin producers and primers/probes to detect producers of neurotoxins, cylindrospermopsins etc. (genes are unknown). The on-going genome projects concerning toxin producing cyanobacteria combined with future gene expression and gene knockout experiments as well as proteome research will yield a wealth of information on the biology and metabolic regulation of these organisms in near future.