Isolation and genome sequencing of 14 Spongia sp. bacterial associates expands the taxonomic and functional breadth of the cultivatable marine sponge microbiome

Marine sponges live with complex microbial consortia, which have been considered as potential sources of novel natural products. However, the usual recalcitrance of host-associated microorganisms to cultivation makes studying sponge symbionts challenging. To tackle this complexity, exploration of cultivated sponge-associated bacteria and their coding potential is unavoidable. In this study, we isolate and report the draft genome sequences of 14 bacterial strains from the marine sponge Spongia sp. using R2A and VXA media. The strains belong to the classes Actinobacteria, Gammaproteobacteria, Alphaproteobacteria, and Cytophagia spanning 11 formally described genera plus two potentially novel genera in the Rhodobacteraceae family and one potentially novel family in the Cytophagales order. Functional genomics revealed presumed symbiosis factors typical of specific taxonomic groups (i.e. taurine metabolism genes among the Alphaproteobacteria, chitinase encoding genes and eukaryotic-like proteins in the Cytophagia genome) while multidrug efflux pumps, also important in host-microbe interactions, were common across all genomes. Moreover, we detected 76 secondary-metabolite biosynthetic gene clusters putatively involved in the production of drug-like compounds or signalling molecules across all genomes, warranting future biotechnologically driven research into their coding potential.