Metagenomic Profiling of Nitrogen Cycling Potential in Caribbean Sponges

Abstract

The high species diversity of coral reefs is in part possible because of the efficient recycling of essential nutrients facilitated by resident organisms and their microbiomes. Sponges and their symbionts play a role in the recycling of nutrients and help ensure productive energy flow, allowing coral reefs to thrive. Here we present a metagenomic analysis of common and abundant sponges from the Caribbean, where microbial metagenome assembled genomes (MAGs) were assembled from shotgun sequencing data and were annotated for metabolic function. We focused on the completeness of nitrogen cycling pathways and the presence of genes from these pathways because bioavailability of nitrogen compounds can be essential in maintaining high biodiversity on coral reefs. We recovered high-quality genomes that spanned twenty-five unique taxa, with eleven of them contributing to the nitrogen cycling potential of the sponge holobiont. Insights on how common reef animals such as sponges interact with biologically important compounds may be a key component in understanding how coral reefs will continue to change in the coming decades.