Identification and characterization of maize rhizospheric bacterial community by 16S ribosomal RNA in the semi-arid area of East Nusa Tenggara, Indonesia

Maize productivity in semi-arid regions such as East Nusa Tenggara Indonesia is significantly hindered by drought stress and low soil fertility resulting in yields well below the national average. The plant rhizosphere, a critical interface between roots and soil, hosts diverse microbial communities, particularly plant growth-promoting rhizobacteria, which are essential for enhancing plant resilience to abiotic stresses. This study aimed to identify and characterize the rhizospheric bacterial community associated with maize in NTT using 16S rRNA gene sequencing. Our findings revealed significant variations in bacterial abundance and community composition across different sites, reflecting environmental heterogeneity. Sample J1_KP exhibited a high abundance of Bacillus and Ammoniphilus spp., known for their roles in improving water use efficiency and stress tolerance through endospore formation. In contrast, sample J8_BTP was dominated by Pseudomonas spp., which are crucial for maintaining plant water status and root morphology under drier conditions. The presence of extremophiles like Melghirimyces thermohalophilus and nutrient cyclers such as Devosia oryziradicis and nitrifying bacteria (Nitrosospira multiformis, Nitrospira japonica) further highlights the adaptive strategies within these communities. This research provides valuable insights into microbial adaptations in challenging semi-arid environments, offering a foundation for developing targeted microbial inoculants to enhance maize resilience and productivity.