The role of beneficial rhizobacteria in plant growth and soil fertility: A comprehensive review

The rising global demand for food, combined with environmental concerns, requires sustainable agricultural practices. Plant Growth-Promoting Rhizobacteria (PGPR) present a promising alternative to chemical fertilizers and pesticides by boosting plant growth, nutrient uptake, and disease resistance. These beneficial microbes colonize the rhizosphere and enhance crop productivity through various mechanisms such as nitrogen fixation, phosphate solubilization, siderophore production, phytohormone synthesis, and induced systemic resistance. Genera like Azospirillum, Bacillus, Pseudomonas, and Rhizobium have demonstrated significant benefits across different crops and stress conditions. PGPR also play critical roles in biocontrol and phytoremediation, making them essential components of biofertilizer and biopesticide formulations. Despite their proven potential, field effectiveness is often inconsistent due to environmental variability, strain-host specificity, and formulation challenges. Advances in microbial biotechnology, development of consortia, and regulatory frameworks are vital to improve their performance and adoption. This review emphasizes the mechanisms, applications, and future opportunities of PGPR in transforming modern agriculture into a more resilient and environmentally friendly system.