Metagenomic Views of Microbial Communities in Sand Sediments Associated with Coral Reefs.

Xiyang Dong,Shengze Weng,Juan Peng,Haoyu Lan,Yongyi Peng,Haikun Zhang,Jia Lin,Jiang-Hai Wang,Xianbiao Lin,Ying Yang,Liangtian Huang

doi:10.1007/s00248-021-01957-8

Abstract

Reef sediments, the home for microbes with high abundances, provide an important source of carbonates and nutrients for the growth and maintenance of coral reefs. However, there is a lack of systematic research on the composition of microbial community in sediments of different geographic sites and their potential effect on nutrient recycling and health of the coral reef ecosystem. In combination of biogeochemical measurements with gene- and genome-centric metagenomics, we assessed microbial community compositions and functional diversity, as well as profiles of antibiotic resistance genes in surface sediments of 16 coral reef sites at different depths from the Xisha islands in the South China Sea. Reef sediment microbiomes are diverse and novel at lower taxonomic ranks, dominated by Proteobacteria and Planctomycetota. Most reef sediment bacteria potentially participate in biogeochemical cycling via oxidizing various organic and inorganic compounds as energy sources. High abundances of Proteobacteria (mostly Rhizobiales and Woeseiales) are metabolically flexible and contain rhodopsin genes. Various classes of antibiotic resistance genes, hosted by diverse bacterial lineages, were identified to confer resistance to multidrug, aminoglycoside, and other antibiotics. Overall, our findings expanded the understanding of reef sediment microbial ecology and provided insights for their link to the coral reef ecosystem health.

Highlights

Coral reefs, composed of coral reef communities and their surrounding marine environment, are one of the ecosystems with the highest level of biodiversity and community complexity in the ocean
Mainly composed of permeable calcium carbonate formed by biological breakdown processes, are one of the important components of coral reef ecosystems (Eyre, et al 2018, Janßen, et al 2017, Shadrack, et al 2020)
Studies largely ignored the role of sediment microbiome in maintaining the stability of coral reef ecosystems

Summary

Introduction

Coral reefs, composed of coral reef communities and their surrounding marine environment, are one of the ecosystems with the highest level of biodiversity and community complexity in the ocean. Corals and the reef ecosystems they support are facing enormous environmental pressures on local and global scales, such as coral bleaching caused by global warming and ocean acidification (Albright, et al 2016, Hughes, et al 2017). Reef sediments contain carbon, nitrogen, sulfur, phosphorus, iron and other chemical elements, most of which exist in the form of nutrient salts These nutrients can help to maintain the high biomass and primary productivity of coral reefs in low-nutrient ocean environments (Duprey, et al 2016, Ning, et al 2019)

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Conclusion