Metagenomic profiling on diversity and gene function of microbial community inhabiting bris soil

Beach Ridges Interspersed with Swales (BRIS) soil, widely distributed along the Kelantan_Terengganu plains, is characterized by poor physical and chemical properties, making it a challenging environment for agriculture. Soil hosts a dynamic ecosystem with diverse microbial communities that play essential roles in metabolic processes and soil health regulation. However, these communities are strongly influenced by physico-chemical properties, and in BRIS soils, the extreme conditions pose significant challenges. A comprehensive understanding of microbial community composition can help identify strategies to improve soil health in BRIS environments. This study investigated the microbial community composition of BRIS soils using a metagenomic approach, evaluated the effects of physico-chemical characteristics, and predicted microbial metabolic functions. Soil samples were collected from four BRIS series (Jambu, Rudua, Baging, and Rhu Tapai) at four depths each. Extracted DNA was analyzed using Illumina Miseq high-throughput sequencing. Alpha diversity and multivariate analyses were performed in R software, while predictive microbial functions were annotated using the Functional Annotation of Prokaryotic Taxa (FAPROTAX). The results showed significant differences in microbial richness among series, with approximately 60% of the total OTUs shared across samples. Dominant phyla included Proteobacteria, Actinobacteria, Bacteroidetes, and Acidobacteria. Principal component analysis (PCA) revealed clustering patterns, while redundancy analysis (RDA) indicated that soil pH, exchangeable aluminium, and base saturation significantly influenced bacterial community structure. A total of 50 out of 92 predicted metabolic functional groups were identified, with _chemoheterotrophy_ being the most abundant function across all samples. These findings highlight that microbial community composition and metabolic functions in BRIS soils are strongly shaped by physico-chemical properties. The dominance of specific microbial taxa and their functional roles underscores the adaptive capacity and ecological significance of microbes in BRIS soils, providing valuable insights for improving soil health in such BRIS environments.