Microbial communities associated with epilithic algal matrix with different morphological characters in Luhuitou fringing reef

The microbiota is an important component of the epilithic algal matrix (EAM) and plays a central role in biogeochemical cycling nutrients coral reef ecosystems. Insufficient studies on EAM diversity have led to limited understanding ecological functions EAMs different states. To explore microbial community Luhuitou fringing Sanya, China, which has undergone incessant expansion domination algae over past several decades, investigations were conducted reef’s intertidal zone. Five types substrate habitats (dead branching coral, dead massive flat granite block, concrete block) selected, their communities analyzed by high-throughput sequencing holobionts using 16S rDNA V4 region. Proteobacteria was most abundant group, accounting for more than 70% reads composition across all sites, followed Cyanobacteria (15.89%) Bacteroidetes (5.93%), respectively. Cluster analysis divided into three groups, namely short, medium, long EAMs. Algal length morphological factor impacting differences microbiota. groups had 52 common OTUs 78.52% sequences, among Vibrio spp. Photobacterium also unique OTUs. short 238 48.61% mainly genera Shewanella Cyanobacterium . medium contained 130 4.36% Pseudomonas Bacillus only 27 4.13% genus Marinobacter Compared with EAM, lower proportion autotrophic bacteria higher potential pathogenic bacteria. It suggested that phenotypes compositions, function changes from increase length. As expanded coastal reefs worldwide, it essential comprehensively structure communities.