Bacterial community structure in the alcyoniid Lobophytum pauciflorum

Abstract

Abstract Corals are associated with diverse and abundant bacterial communities, some members of which may promote host health through the exclusion of pathogens, increased environmental resilience, and by extending metabolic pathways in the holobiont. Much of our understanding of the microbiomes associated with anthozoans is derived from studying Scleractinia, though the Alcyonacea also harbour diverse microbial communities. This study examined the bacterial community associated with the alcyoniid Lobophytum pauciflorum, using 16S rRNA gene amplicon sequencing to document patterns between colonies and within the inner tissue, outer tissue and the mucus layer microhabitats. Tissue layers hosted similar bacterial communities, dominated by sequences affiliated with Endozoicomonadaceae, particularly the genus Parendozoicomonas. Sequences affiliated with Spirochaetaceae were also abundant in some colonies but were less evenly distributed among colonies. The bacterial community associated with the mucus layer was distinct from the tissue layers and its phylogenetic diversity was two-fold higher. The results from this study demonstrate that L. pauciflorum hosts a diverse bacterial community that is relatively stable at the colony level. Importantly, this study identifies the microhabitat specific communities that may have important roles in Alcyonacea health.