Isolation and Identification of <em>Bacillus stercoris</em> CMB2 with Nitrogen-Fixing and Phosphate Solubilizing Capabilities from Baby Maize Roots

Baby maize (Zea mays L.) is one of the important food crops in Asian regions and exhibits strong adaptability to adverse conditions across diverse agroecological zones. However, maize is commonly cultivated on nutrient-poor soils and under dry conditions, resulting in low fertilizer use efficiency and unstable baby maize yields across cropping seasons. Excessive application of chemical fertilizers, particularly nitrogen and phosphorus fertilizers, not only increases production costs but also contributes to soil degradation and environmental pollution. Beneficial endophytic bacteria, especially nitrogen-fixing and phosphate-solubilizing bacteria, have been recognized as sustainable biological solutions to enhance nutrient acquisition and improve crop productivity. The main objective of this study was to isolate, identify, and biologically characterize an endophytic bacterial strain possessing both nitrogen-fixing and phosphate-solubilizing capabilities from baby maize root tissues, with the aim of promoting plant growth and increasing baby maize yield under nutrient-deficient conditions. The study was conducted at the Central Laboratory, An Giang University, Vietnam. Among ten bacterial isolates screened, Bacillus stercoris CMB2 (B. stercoris CMB2) was successfully isolated, identified, and selected due to its outstanding abilities in atmospheric nitrogen fixation and solubilization of insoluble phosphorus compounds. The application of B. stercoris CMB2 demonstrated considerable potential for sustainable baby maize cultivation by improving soil nutrient status, enhancing fertilizer use efficiency, and increasing baby maize productivity in nutrient-poor soils.