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A collection of polar cyanobacteria to contribute to the inventory of the biodiversity and discover the biotechnological potential

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Academic year: 2021

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A collection of polar cyanobacteria to contribute to the inventory of the biodiversity and discover the biotechnological potential Wilmotte, A.1, Waleron, K.2, Waleron, M.2, Namsaraev, Z.1, Simon, P.1, Renard,

M.1, Vincent, W.F.4, Castenholz, R.W.5, Marinelli, F.6, Komarek, J.7, Elster, J.7 1 - University of Liege, Centre for Protein Engineering, Liege, Belgium.

awilmotte@ulg.ac.be

2 - University of Gdansk, Department of Biotechnology, Gdansk, Poland 3 - University of Ghent, Laboratory of Microbiology, Ghent, Belgium

4 - Universite Laval, Department of Biology, Quebec, Canada 5 - University of Oregon, Department of Biology, Eugene, USA

6 - University of Insuburia, DBSM, Varese, Italy

7 – University of South Bohemia, Ceske Budejovice, Czech Republic

Since 2005, the BCCM (Belgian Co-ordinated Collections of Microorganisms) has suppported the elaboration of a collection of polar cyanobacteria (ULC) and the construction of an Assurance Quality system.

It includes 125 unicyanobacterial strains coming from different Antarctic (South Victoria Land, East Antarctica, Transantarctic Mountains...) and Arctic regions (North Canada, Alaska,...), as well as different biotopes (microbial mats, ice shelves, hypolithic and endolithic habitats, ...). The three main orders of cyanobacteria (Chroococcales, Oscillatoriales, Nostocales) are represented.

Taxonomic characterisations include the sequencing of the 16S rRNA gene and the spacer between the 16S and 23S (ITS), as well as genomic fingerprints obtained with variants of the HIP repeats (Smith et al., Microbiol. 1998 ), and the RFLP of rpoC1 and recA gene fragments.

Several Antarctic strains were already screened for bioactivity against pathogenic bacteria and fungi (Taton et al. J. Phycol, 2006; Biondi et al. J. Appl. Microbiol, 2008). About 120 chemically diverse extracts were generated from 48 strains and screened by antimicrobial assays and cytotoxicity tests. Besides the high percentage of cytotoxic activities, they showed a widely distributed activity versus Gram positives, and few but very interesting activities against fungal pathogens. 17 strains were bioactive against the Gram-positive

Staphylococcus aureus, or the fungi Aspergillus fumigatus and Cryptococcus neoformans and 25 were cytotoxic against HeLa cells. The bioactivities were

not in accordance with the phylogenetic relationships, but rather strain-specific. These data confirm the renewed interested for biotechnological exploitation of cyanobacteria.

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