Biodegradation of Tribenuron-Methyl by <i>Microbacterium paraoxydans</i> BS3-TBM: Optimization and Toxicological Evaluation

Abstract

This study presents an innovative approach to eco-friendly pesticide removal by investigating the biodegradation of tribenuron-methyl (TBM) using a novel bacterial strain, Microbacterium paraoxydans BS3-TBM, isolated from TBM-contaminated agricultural soil. Identified through 16S rRNA analysis, this strain demonstrated remarkable potential by utilizing TBM as its sole carbon source. Under optimal conditions─TBM concentration of 5.25 mg/L, inoculum volume of 9.9% (v/v), and pH of 5.008─Microbacterium paraoxydans BS3-TBM achieved a 99% degradation of TBM within just 5 days, as predicted by an Artificial Neural Network-Genetic Algorithm (ANN-GA) model. Analysis of the degradation intermediates revealed the formation of N-methyl-4-methoxy-6-methyl-1,3,5-triazin-2-amine (N-MTA) and Methyl 2-(aminosulfonyl) benzoate (MASB) due to TBM hydrolysis. Importantly, both N-MTA and MASB were completely removed following biological treatment using the bacterial strain Microbacterium paraoxydans BS3-TBM. Toxicity assays using the microalgae Nannochloropsis gaditana confirmed a significant reduction in the toxicity of the treated TBM solution compared to the untreated sample. These findings highlight the effectiveness and environmental safety of using Microbacterium paraoxydans BS3-TBM for TBM removal, offering a promising solution for sustainable pesticide degradation.