Evaluation of Soil Beneficial Bacteria as Plant Growth Enhancer and Biocontrol Agents

The use of soil beneficial bacteria, particularly plant growth-promoting rhizobacteria (PGPR), provides an eco-friendly alternative to synthetic agrochemicals in sustainable agriculture. This study aimed to isolate and characterize soil bacterial isolates from the rhizosphere of cabbage cultivation areas in Cameron Highlands, Malaysia, and evaluate their potential as PGPR and biocontrol agents. A total of 42 bacterial isolates were obtained, of which 15 were selected for detailed screening. Morphological and molecular characterization using 16S rDNA sequencing identified species from the genera Bacillus, Pseudomonas, and Serratia. These isolates exhibited key plant growth-promoting traits, including nitrogen fixation, phosphate solubilization, and potassium solubilization. Notably, isolates S9 and S30 demonstrated both plant growth-promoting and antibacterial activities against Xanthomonas campestris, a major pathogen of cabbage. Meanwhile, isolates S16 and S36, although lacking antibacterial activity, showed strong growth-promoting capabilities. These findings highlight the potential of native soil beneficial bacteria as biofertilizers and biocontrol agents, contributing to sustainable agricultural practices by reducing reliance on chemical fertilizers and pesticides. Future research should focus on field trials to validate their efficacy under diverse environmental conditions.