Fig. 5

Secondary metabolite coding potential in the prokaryotic communities of healthy and necrotic octocoral samples and seawater. a Distribution of biosynthetic gene clusters (BGCs, N = 462) across these 17 assembled, metagenomes. The BGC counts per compound class were obtained using antiSMASH version 5.0. b Principal component analysis (PCA) biplot based on the BGCs (arrows) found in the metagenomes of the microbiomes of healthy (EG_H, salmon circles) and necrotic (red triangles; EG_N) Eunicella gazella tissue, healthy Eunicella verrucosa (orange circles; EV01 - EV04), healthy Leptogorgia sarmentosa (olive circles; LS06 - LS08), and seawater (blue asterisks; SW01 - SW04). c Similarity network of 455 BGCs predicted by antiSMASH and grouped into biosynthetic gene cluster families (GCFs) across seven major compound classes using the BiG-SCAPE algorithm. The network was rendered in Cytoscape. Nodes represent amino acid sequences of BGC domains, and their different shapes indicate the origin of the sampled metagenome. BGC classes are color-coded with number of GCFs per class given in brackets. A majority of the GCFs (“Others,” N = 169) could not be classified using current BiG-SCAPE BGC nomenclature. Most GCFs were composed by only one BGC (singletons), with GCFs containing two or more BGCs represented through BGC networks inferred from protein sequence homology. PKS, polyketide synthase; NRPS, non-ribosomal peptide synthetase; RiPPs, ribosomally synthesized and post-translationally modified peptides; hserlactone, homoserine lactone; CDPS, tRNA-dependent cyclodipeptide synthases; hglE-KS, heterocyst glycolipid synthase-like PKS; LAP, linear azol(in)e-containing peptides