19Marine sponges live with complex microbial consortia, which have been considered as 20 potential sources of novel natural products. However, the usual recalcitrance of host-21 associated microorganisms to cultivation makes studying sponge symbionts challenging. To 22 tackle this complexity, exploration of cultivated sponge-associated bacteria and their coding 23 potential is unavoidable. In this study, we isolate and report the draft genome sequences of 14 24 bacterial strains from the marine sponge Spongia sp. using R2A and VXA media. The strains 25 belong to the classes Actinobacteria, Gammaproteobacteria, Alphaproteobacteria, and 26 Cytophagia spanning 11 formally described genera plus two potentially novel genera in the 27Rhodobacteraceae family and one potentially novel family in the Cytophagales order. 28Functional genomics revealed presumed symbiosis factors typical of specific taxonomic 29 groups (i.e. taurine metabolism genes among the Alphaproteobacteria, chitinase encoding 30 genes and eukaryotic-like proteins in the Cytophagia genome) while multidrug efflux pumps, 31 1 Current affiliation: Sorbonne Universités/CNRS, Station Biologique de Roscoff, UMR 8227, Integrative Biology of Marine Models, CS 90074, Roscoff, France also important in host-microbe interactions, were common across all genomes. Moreover, we 32 detected 76 secondary-metabolite biosynthetic gene clusters putatively involved in the 33 production of drug-like compounds or signalling molecules across all genomes, warranting 34 future biotechnologically driven research into their coding potential. 35
Keywords 36Porifera, genomics, host-microbe interactions, symbiosis, marine microbiology, secondary 37 metabolite 38