Using degrading endophytic bacteria to detoxify the phthalic acid esters in crops from contaminated soil

Abstract

Phthalic acid esters (PAEs) are widely released into the environment due to industrial and agricultural activities. This poses significant risks, not only to crops grown on contaminated soil but also to humans. PAEs enter the human body through the food chain, causing potential health hazards. Endophytic bacteria have demonstrated a significant potential as effective bioremediation agents, with specialized mechanisms of PAEs degradation. Endophytic bacteria such as Rhodococcus, Pseudomonas and Sphingomona recognize root exudates, adhere to and penetrate root surfaces, and ultimately colonize crops. They form symbiotic relationships with crops, obtaining nutrients and habitats from crops, meanwhile, promoting plant growth and health through hormone production, nutrient regulation, and the suppression of pathogenic microorganisms. Furthermore, endophytic bacteria efficiently degrade PAEs in soil-crop systems through synergistic interactions with indigenous rhizosphere microflora and regulatory effects on enzyme activity in crops. Here, we review the role of endophytic bacteria in the bioremediation of PAEs-contaminated crops and soils. In addition, we discuss the scarcity of endophytic bacterial strains with a confirmed ability to degrade PAEs, and underscore the lack of the research on the mechanisms of PAEs degradation by these bacteria. This review also points out that future study should investigate the molecular mechanisms underlying the interaction between endophytic bacteria and PAEs to offer novel insights and solutions for environmental protection and sustainable agricultural development.