Plant growth-promoting bacteria as biological controls for sustainable crop protection against agricultural biodeterioration

Agricultural biodeterioration caused by phytopathogenic microorganisms, soil-dwelling pests, and abiotic stress factors represents a critical threat to global food security, resulting in annual crop losses exceeding $220 billion worldwide. Plant growth-promoting bacteria (PGPB) emerge as sustainable biological solutions for controlling multiple biodeterioration agents while enhancing crop resilience and productivity. This comprehensive review examines PGPB mechanisms in suppressing agricultural biodeterioration through direct antagonism (antibiotic production, lytic enzyme secretion, volatile organic compound emission), competitive exclusion (nutrient sequestration, niche occupation, biofilm formation), and induced systemic resistance (defense gene priming, antimicrobial compound synthesis, structural barrier reinforcement). Key biocontrol species including Pseudomonas fluorescens, Bacillus subtilis, Trichoderma harzianum, and Azospirillum brasilense demonstrate 40–85% efficacy against major deteriorative agents such as Fusarium spp., Rhizoctonia solani, Pythium ultimum, and plant-parasitic nematodes. PGPB simultaneously prevent abiotic deterioration by enhancing plant tolerance to drought, salinity, and heavy metal stress through ACC deaminase activity, osmoprotectant production, and antioxidant system enhancement. Despite proven anti-deteriorative properties, commercialization faces challenges including environmental variability (35–80% efficacy fluctuation), formulation instability (50–90% viability loss during storage), and regulatory complexity. Emerging technologies including synthetic biology, precision application systems, and multi-strain consortia offer promising solutions for developing next-generation biocontrol agents with enhanced reliability and broader spectrum activity. This analysis provides critical insights for integrating PGPB into comprehensive biodeterioration management strategies essential for sustainable agricultural intensification.