BCCM/ULC, a culture collection to explore diversity and bioactivity of (sub)polar cyanobacteria

The BCCM/ULC public collection of (sub)polar cyanobacteria is funded since 2011 by the Belgian Science Policy Office. A Quality Management System was implemented and is continuously improved since then. An ISO9001 certificate was obtained for the public deposition and distribution of strains, as part of the multi-site certification for the BCCM consortium. BCCM/ULC is currently holding 134 cyanobacterial strains and the catalogue is available on http://bccm.belspo.be/catalogues/ulc-catalogue-search Continuous maintenance of living cultures, some of which are also cryopreserved, ensure the preservation and the possibility to rapidly deliver strains to clients for fundamental and applied research.

The collection includes 113 (sub)polar strains. In such extreme environments, cyanobacteria are important phototrophs and primary producers in terrestrial and freshwater ecosystems. The purpose of this public collection is to gather a representative portion of the cyanobacterial diversity with different ecological origins (limnetic microbial mats, soil crusts, cryoconites, endoliths, etc.) and make it available for researchers to study the taxonomy, evolution, adaptations to environmental conditions, and genomic make-up. Thus, 102 cyanobacterial strains were isolated from the three main biogeographic zones of the Antarctic continent. In addition, 7 strains were isolated in Arctic biotopes and 4 from Siberian lakes. The molecular characterization is underway, on the basis of 16S rRNA and ITS sequences. The diversity encompasses the three main cyanobacterial orders: Chroococcales, Oscillatoriales and Nostocales. This is particularly important in view of the emerging use of metagenomic approaches on environmental samples, where the comparisons with the genome sequences from well-defined strains is very useful.

In addition, cyanobacteria are known to produce a range of secondary metabolites (e.g. alkaloides, cyclic and linear peptides, polyketides) with different bioactive potential (e.g. antibiotic, antiviral, antifungal, anticancer, cytotoxic). The potential of the polar strains to produce cyanotoxins is currently studied by ELISA and the detection by PCR of genes involved in their production. Due to the geographic isolation and the strong environmental stressors of the habitat, the exploration of these metabolites in Antarctic cyanobacterial strains seems especially promising for biotechnology or biomedical applications.

In summary, the BCCM/ULC public collection could serve as a general reference for (sub)polar cyanobacteria with multiple applications (pigments, UV screens, …), as well as a resource for novel bioactive compounds