ORIGINAL ABSTRACT

The proceeding study aimed to isolate glyphosate-degrading bacteria from soil and determine optimal degradation conditions through single-factor experiments and response surface methodology. The detoxifying efficacy of the isolate on glyphosate was assessed using earthworm model. The results indicate that Pseudomonas putida HE exhibited the highest glyphosate degradation rate. Optimal conditions for glyphosate degradation were observed at an inoculation percentage of approximately 5%, a pH of 7, and a temperature of 30 °C. Glyphosate induced notable neurotoxicity and reproductive toxicity in earthworms, evidenced by reduced activity of the neurotoxicity-associated enzyme AChE. Additionally, an increase in the activities of catalase, superoxide dismutase, and lactate dehydrogenase was observed. H&E staining revealed structural disruptions in the earthworm clitellum, with notable atrophy in the structure of spermathecae. Furthermore, glyphosate activation of earthworm immune systems led to increased expression of immune-related genes, specifically coelomic cytolytic factor and lysozyme. Notably, the introduction of strain HE mitigated the glyphosate toxicity to the earthworms mentioned above. P. putida HE was able to increase soil enzyme activities that were reduced due to glyphosate. The isolate P. putida HE, emerged as an effective and cost-efficient remedy for glyphosate degradation and toxicity reduction in natural settings, showcasing potential applications in real ecological settings.