Correspondence of coral holobiont metabolome with symbiotic bacteria, archaea and Symbiodinium communities

Microbial symbiotic partners, such as those associated with reef-building corals, mediate biochemical transformations that influence host performance and survival. While evidence suggests microbial community composition partly accounts for differences in coral physiology, how these symbionts affect metabolic pathways remains underexplored. We aimed to assess functional variation between coral-associated microbial partners in hospite. To this end, we characterized and compared microbial community composition and metabolomic profiles from 9 coral species. These data support and expand on previous research by demonstrating microbial communities and metabolite profiles are species-specific and are correlated to one another. Using Porites spp. as a case study, we present evidence that the relative abundance of different sub-clades of Symbiodinium and bacterial/archaeal families influence the composition of functionally important metabolites. Our data suggests that while some microbial partners benefit the union, others are more opportunistic and possibly parasitize the host. Consequently, coral partner choice likely influences cellular metabolic activities and, therefore, holobiont nutrition.