bioRxiv preprint doi: https://doi.org/10.1101/2020.05.18.103358; this version posted May 21, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY 4.0 International license. 1 Phytoplankton trigger the production of cryptic metabolites in the marine 2 actinobacteria Salinispora tropica. 3 4 Audam Chhun1,#, Despoina Sousoni1, Maria del Mar Aguiló-Ferretjans2, Lijiang Song3, Christophe 5 Corre1,3,#, Joseph A. Christie-Oleza1,2,4,# 6 7 1 School of Life Sciences, University of Warwick, Coventry, UK 8 2 University of the Balearic Islands, Palma, Spain 9 3 Department of Chemistry, University of Warwick, Coventry, UK 10 4 IMEDEA (CSIC-UIB), Esporles, Spain 11 12 #Corresponding authors:
[email protected],
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[email protected] 13 14 15 Abstract 16 Bacteria from the Actinomycete family are a remarkable source of natural products with 17 pharmaceutical potential. The discovery of novel molecules from these organisms is, 18 however, hindered because most of the biosynthetic gene clusters (BGCs) encoding these 19 secondary metabolites are cryptic or silent and are referred to as orphan BGCs. While co- 20 culture has proven to be a promising approach to unlock the biosynthetic potential of many 21 microorganisms by activating the expression of these orphan BGCs, it still remains an 22 underexplored technique. The marine actinobacteria Salinispora tropica, for instance, 23 produces valuable compounds such as the anti-cancer molecule salinosporamide A but half 24 of its putative BGCs are still orphan.