Comparative microbial ecology of seagrass and coral reef sediments in the Lakshadweep archipelago using...

Seagrass and coral reef sediments from Minicoy Island were investigated to compare bacterial community composition and predicted functional potential using 16S rRNA gene (V3-V4) amplicon sequencing. Sequence data were processed in QIIME2 with Deblur-generated amplicon sequence variants and taxonomic classification against the SILVA database. Alpha and beta diversity analyses revealed high similarity in microbial community composition between seagrass and coral reef sediments, indicating strong ecological connectivity within the atoll environment. Proteobacteria, Bacteroidota, and Desulfobacterota were dominant across both habitats, while sulfate-reducing families such as Desulfobulbaceae and Desulfobacteraceae were relatively enriched in seagrass sediments. Correlation analysis showed that microbial diversity was positively associated with nutrient concentrations and turbidity, and negatively associated with temperature and particulate organic carbon. Functional prediction using PICRUSt2 and KEGG pathway annotation identified habitat-associated trends in transport- and signalling-related pathways, although these functional differences were interpreted cautiously due to the limitations of predictive approaches. Henceforth, the study provides a baseline assessment of benthic microbial communities in Lakshadweep ecosystems and highlights the need for geographically independent sampling and multi-omics approaches to validate functional and ecological inferences.