| Summary: | In the Polar Regions, Cyanobacteria represent key primary producers and are the main drivers of the food webs in a wide range of aquatic to terrestrial habitats. For example, they build benthic microbial mats in lakes and soil crusts in terrestrial biotopes. They may present interesting features to survive freeze/thaw cycles, seasonally contrasted light intensities, high UV radiations, dessication and other stresses. The BCCM/ULC public collection funded by the Belgian Science Policy Office since 2011 aims to gather a representative portion of the polar cyanobacterial diversity with different ecological origins (limnetic mats, soil crusts, cryoconites, endoliths…). It makes it available for researchers to study the taxonomy, evolution, adaptations to harsh environmental conditions, and genomic make-up. It presently includes 226 cyanobacterial strains, with 119 being of Antarctic origin (catalogue: http://bccm.belspo.be/catalogues/ulc-catalogue-search). An ISO 9001 certificate was obtained for the public deposition and distribution of strains, as part of the multi-site certification for the BCCM consortium. The morphological identification shows that the strains belong to the orders Synechococcales, Oscillatoriales, Pleurocapsales, Chroococcidiopsidales and Nostocales. The 16S rRNA and ITS sequences of the strains are being characterized. Our results show that the Antarctic strains are positioned into 25 OTUs (sequences with > 97,5% 16S rRNA similarity), and thus, represent a quite large diversity. In addition, cyanobacteria are known to produce a wide range of secondary metabolites (e.g. alkaloids, cyclic and linear peptides, polyketides) with bioactive potential. Among these bioactive metabolites, some display antibiotic, anticancer or antifungal effects. In collaboration with the BCCM/IHEM collection of biomedical fungi, a screening of cyanobacterial strains from BCCM/ULC was performed in order to discover potential new antifungal drugs. The analysis of a first set of methanol extracts from 15 different ...
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