Cyanobacteria in Azorean lakes and hot springs: biodiversity assessment and toxin monitoring.

Objectivo

Culture banks are a resource of living cultures of organisms such as algae, cyanobacteria, or other, maintained in comfortable growth conditions for future uses. The culture collections are important resources for research and are regularly accessed by industries, universities or researchers. Cultures of isolated strains of cyanobacteria are important to study their biodiversity (morphological, genetic and biochemical diversity), their ecological implications and environmental behaviour, and the properties and impacts of their secondary metabolites. Cyanobacteria are a high source of secondary metabolites, some with pharmaceutical properties, other with industrial applications (e.g. production of biofuels), and also some with toxic properties (cyanotoxins). Recognizing the importance of cyanobacteria and their toxins, a monitoring program in which is determined the concentration of microcystins by standard analytical methods (HPLC) and the presence of cyanobacteria by microscopy observation and identification was implemented in the archipelago. Regardless, previous studies shown that other cyanotoxins (saxitoxin, anatoxin-a and cylindrospermopsin) apart from microcystins may be present in Azorean lakes since several genera that are known to produce them (e.g. Anabaena sp. and Aphanizomenon sp.) are present in high abundance in these waters. Due to environmental factors, such as geographic isolation or physicochemical conditions of the habitat, Azorean cyanobacteria can present differences in taxonomic, ecological or biochemical levels from continental species. Taking this into consideration, in this work we propose the creation of the first collection of cyanobacteria strains isolated from Azorean lakes and hot springs, their genetic characterization, and the development of molecular methodologies (based on conventional PCR and DNA electrophoresis) for their detection in environmental samples.

In articulation with the Azorean Inland Waters Monitoring Program (Concurso Público Nº 1/DRA/2014), seasonal sampling of planktonic and benthic habitats will be carried out in 23 lakes in São Miguel, Pico, Flores and Corvo islands. Additionally, several hot springs in São Miguel Island will also be sampled to study the diversity of extremophile cyanobacteria. Cyanobacteria present in these samples will be isolated and characterized by molecular markers. For cyanotoxin production potential in lake waters, parts of the gene clusters mcy, sxt, ana and cyn will be targeted to identify the potential for microcystin, anatoxin-a, saxitoxin and cylindrospermopsin production, respectively.

Thus it is expected to exhaustively study the presence of cyanobacteria species in Azores inland waters and the presence of cyanotoxin producing genes in order to propose a surveillance system and more accurate guideline for warning about the presence of cyanotoxins in the Azores, so that it prevents contact of the population with these toxins harmful to health.