Metagenomic Characterization of Microbiome Taxa Associated with Coral Reef Communities in North Area of Tabuk Region, Saudia Arabia

The coral microbiome is highly related to the overall health and the survival and proliferation of coral reefs. The Red Sea's unique physiochemical characteristics, such a significant north-south temperature and salinity gradient, make it a very intriguing research system. However, the Red Sea is rather isolated, with a very diversified ecosystem rich in coral communities, and the makeup of the coral-associated microbiome remains little understood. Therefore, comprehending the makeup and dispersion of the endogenous microbiome associated with coral is crucial for understanding how the coral microbiome coexists and interacts, as well as its contribution to temperature tolerance and resistance against possible pathogens. Here, we investigate metagenomic sequencing targeting 16S rRNA using DNAs from the sediment samples to identify the coral microbiome and to understand the dynamics of microbial taxa and genes in the surface mucous layer (SML) microbiome of the coral communities in three distinct areas close to and far from coral communities in the Red Sea. These findings highlight the genomic array of the microbiome in three areas around and beneath the coral communities and revealed distinct bacterial communities in each group, where <i>Pseudoalteromonas agarivorans</i> (30%), <i>Vibrio owensii</i> (11%), and <i>Pseudoalteromonas</i> sp. Xi13 (10%) were the most predominant species in samples closer to coral (a coral-associated microbiome), with the domination of <i>Pseudoalteromonas_agarivorans</i> and <i>Vibrio_owensii</i> in Alshreah samples distant from coral, while <i>Pseudoalteromonas</i>_sp._Xi13 was more abundant in closer samples. Moreover, Proteobacteria such as <i>Pseudoalteromonas</i>, <i>Pseudomonas</i> and <i>Cyanobacteria</i> were the most prevalent phyla of the coral microbiome. Further, Saweehal showed the highest diversity far from corals (52.8%) and in Alshreah (7.35%) compared to Marwan (1.75%). The microbial community was less diversified in the samples from Alshreah Far (5.99%) and Marwan Far (1.75%), which had comparatively lower values for all indices. Also, <i>Vibrio</i> species were the most prevalent microorganisms in the coral mucus, and the prevalence of these bacteria is significantly higher than those found in the surrounding saltwater. These findings reveal that there is a notable difference in microbial diversity across the various settings and locales, revealing that geographic variables and coral closeness affect the diversity of microbial communities. There were significant differences in microbial community composition regarding the proximity to coral. In addition, there were strong positive correlations between genera <i>Pseudoalteromonas</i> and <i>Vibrio</i> in close-to-coral environments, suggesting that these bacteria may play a synergistic role in Immunizing coral, raising its tolerance towards environmental stress and overall coral health.