Metagenomics insights into microbial diversity shifts among seagrass sediments

Abstract

Seagrasses are important in marine ecosystems by providing food and shelter for animals, storing carbon, and reducing sulfide and methane emissions. Previous studies found variations in the microbiomes of seagrass both above and below sediment surface, with certain microbes serving as indicators of seagrass health. Despite numerous studies on bacterial communities in specific seagrass species, little is known about bacterial communities in mixed seagrass beds. This study used metagenomics to investigate microbial diversity in bare and seagrass-associated sediments, across seven seagrass species combinations. The findings revealed higher alpha diversity of bacteria and archaea in the upper layers, whereas microbial eukaryotes were more diverse in the lower layers. Significant taxonomic differences were found between bare and seagrass sediments, and among seagrass species. Several metagenome-assembled genomes were reconstructed, primarily from Pseudomonadota and Thermodesulfobacteriota. This study improves our understanding of complex interactions between seagrasses and their associated microbial communities and laying a foundation for efficient strategies for the management and restoration of seagrass ecosystems.