Glyphosate in the environment: Pollution dynamics, fate, microbial degradation and associated pathways

Glyphosate (GlyP), an extensively used broad-spectrum herbicide, has revolutionized weed management in modern agriculture. However, its widespread application has become a subject of global environmental concern due to its extensive agricultural application and persistent ecological footprint. Although GlyP was initially recognized for its high efficacy and low human toxicity, increasing evidence highlights its widespread environmental contamination, with residues detected in soil, water, foodstuffs, and non-target organisms, including humans. The environmental pollution and potential human health threats arising from the widespread use of GlyP underscore the urgent need for effective alternatives for its removal and treatment. While various treatment technologies exist for mitigating GlyP contamination, bioremediation has emerged as a promising, eco-friendly solution. Although there is considerable research on the fate and toxicity of GlyP, reviews focusing on its environmental contamination and biodegradation mechanisms remain limited. This review consolidates recent research on GlyP’s chemistry and mode of action, environmental fate and contamination, and a summary of latest findings on its biodegradation and potential degradation pathways. Two predominant pathways have been elucidated: GlyP oxidoreductase (GOX) pathway, which cleaves the C–N bond to produce aminomethylphosphonic acid (AMPA) and glyoxylate, and the C–P lyase pathway, which targets the C–P bond, yielding sarcosine and inorganic phosphate. These pathways are encoded by specific genes, notably the GOX family in bacteria such as Ochrobactrum and Pseudomonas , and the phn operon in phosphate-limited environments. Understanding the enzymatic mechanisms underlying GlyP degradation not only clarifies its environmental fate but also opens avenues for designing microbial systems with enhanced detoxification potential.