Biochemical, functional, and molecular profiling of three bacterial isolates with bioremediation potential for...

The primary focus of the current research was to isolate and characterize imidacloprid (IM) degrading bacteria found in maize field soils. The characterization encompassed various aspects, including morphological, biochemical, functional, and sequencing analyses of these bacterial cultures. Furthermore, the study assessed the potential of these bacterial cultures to bioremediate IM contaminated soil, comparing their efficacy with untreated soil. The quantification of IM and its metabolites viz., 6-chloronicotinic acid (6-CNA), 5-hydroxy imidacloprid (5-OH-IM), Imidacloprid-urea (IM-urea), Imidacloprid-olefin (IM-olefin), and desnitro-imidacloprid hydrochloride (DN-IM.HCl) residues in soil was conducted using Liquid Chromatography tandem Mass Spectrometry after extraction using Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERs) methodology. The limit of quantification (LOQ) for IM and its metabolites in soil was determined to be 0.01 mg kg^-1. Upon amending the soil with Pseudomonas sp., Bacillus subtilis, and Enterobacter cloacae, there was a noticeable increase in the percentage of IM degradation compared to untreated soils. This significant enhancement in degradation percentages across various concentrations of IM underscores the effectiveness of these microbial strains as catalyzing agents for the bioremediation process. Consequently, these findings suggest promising potential for utilizing these bacterial strains in bioremediation strategies aimed at alleviating IM contamination in soil environments.