Molecular Detection of Genes Responsible for Cyanobacterial Toxin Production in the Genera Microcystis, Nodularia, and Cylindrospermopsis

2004 ◽  
pp. 213-222 ◽  
Author(s):  
Brendan P. Burns ◽  
Martin L. Saker ◽  
Michelle C. Moffitt ◽  
Brett A. Neilan
2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Konstantinos Ar. Kormas ◽  
Despoina S. Lymperopoulou

Cyanobacteria are ubiquitous in nature and are both beneficial and detrimental to humans. Benefits include being food supplements and producing bioactive compounds, like antimicrobial and anticancer substances, while their detrimental effects are evident by toxin production, causing major ecological problems at the ecosystem level. To date, there are several ways to degrade or transform these toxins by chemical methods, while the biodegradation of these compounds is understudied. In this paper, we present a meta-analysis of the currently available 16S rRNA andmlrA(microcystinase) genes diversity of isolates known to degrade cyanobacterial toxins. The available data revealed that these bacteria belong primarily to the Proteobacteria, with several strains from the sphingomonads, and one from each of theMethylobacillusandPaucibactergenera. Other strains belonged to the generaArthrobacter, Bacillus, andLactobacillus. By combining the ecological knowledge on the distribution, abundance, and ecophysiology of the bacteria that cooccur with toxic cyanobacterial blooms and newly developed molecular approaches, it is possible not only to discover more strains with cyanobacterial toxin degradation abilities, but also to reveal the genes associated with the degradation of these toxins.


2017 ◽  
Vol 18 (5) ◽  
pp. 1719-1726
Author(s):  
Cameron James Veal ◽  
Catherine Neelamraju ◽  
T. Wolff ◽  
A. Watkinson ◽  
D. Shillito ◽  
...  

Abstract The management of inland waterways to protect recreational users from cyanotoxin exposure is complicated by the common management practice of using proxy indicators of cyanotoxin production (cell counts and biovolumes of potentially toxin species), rather than the cyanotoxin itself. This widely accepted practice is further complicated by a lack of advisory guidelines for non-microcystin-producing cyanotoxins. This study has investigated the effectiveness of this management approach over five and a half years, monitoring 65 different sites in South East Queensland using phycological and toxin-analysis. This study concluded that cell counts of Cylindrospermopsis raciborskii, the most common potentially toxin producing species of cyanobacteria in South East Queensland's inland lakes, was a poor proxy indicator for cylindrospermopsin toxin production. Seqwater, the local water authority responsible for the management of recreational access to drinking water storage lakes, initiated an alternative management approach for recreational cyanobacterial water quality management in December 2016. This new approach is based on cyanobacterial toxin guideline values for five different cyanotoxins, with closures and warning notices issued based on the actual cyanotoxin concentration, not the proxy indicator. We encourage other recreational water management authorities consider this approach to manage recreational access in the future.


1989 ◽  
Vol 21 (3) ◽  
pp. 1-13 ◽  
Author(s):  
Geoffrey A. Codd ◽  
Steven G. Bell ◽  
William P. Brooks

Cyanobacteria (blue-green algae) commonly occur in fresh- and brackish waters and may produce massive annual growths as a consequence of nutrient enrichment from natural waters, agricultural fertilizer run-off, or from domestic/industrial effluents. The cyanobacterial species which dominate these growths typically belong to the genera which produce toxins. Cyanobacterial toxins cause fatal poisonings of agricultural livestock, wild animals, birds and fish on a world-wide basis. The involvement of the toxins in human health problems has also been inferred in several countries and their presence in drinking water sources is of interest to the drinking water industry. The occurrence and properties of cyanobacterial toxins are discussed here. New methods are being developed for the purification of the toxins and for their recovery and quantification from waters. These include the use of chemical, cytotoxicity and immunological methods to complement the mouse bioassay which has hitherto been used in cyanobacterial toxin studies with laboratory cultures and water samples. Information on the regulation of cyanobacterial toxin production and on the possible biological significance of the toxins in aquatic environments is also presented. A greater awareness of cyanobacterial toxins in waters destined for human use is required.


2018 ◽  
Author(s):  
Ana P. Semedo-Aguiar ◽  
José B. Pereira-Leal ◽  
Ricardo B. Leite

AbstractThe Cape Verde islands are part of the African Sahelian arid belt that possesses an irregular rainy season between August and October. This erratic rain pattern has prompted the need for water reservoirs, now critical for the country’s sustainability. Worldwide, freshwater cyanobacterial blooms are increasing in frequency due to global climate change and eutrophication of water bodies, particularly in reservoirs. To date there have been no risk assessments of cyanobacterial toxin production in these man-made structures. We evaluated this potential risk using 16S rRNA gene amplicon sequencing and full metagenome sequencing in freshwater reservoirs of Cape Verde.Our analysis revealed the presence of several potentially toxic cyanobacterial genera in all sampled reservoirs (Poilão, Saquinho and Faveta). In Faveta Microcystis sp., a genus well known for toxin production and bloom-formation, dominated our samples, while a green algae of the genus Cryptomonas and Gammaproteobacteria dominated Saquinho and Poilão.Taking advantage of the dominance of Microcystis in the Faveta reservoir, we were able to reconstruct and assemble its genome, extracted from a metagenome of bulk DNA from Faveta water. We named it Microcystis cf. aeruginosa CV01, for which a phylogenetic analysis revealed to have a close relationship with other genomes from those taxa, as well as other continental African strains, suggesting geographical coherency. In addition, it revealed several clusters of known toxin-producing genes. This assessment of Cape Verdean freshwater microbial diversity and potential for toxin production reinforces the need to better understand the microbial ecology as a whole of water reservoirs on the rise.


Sign in / Sign up

Export Citation Format

Share Document