Biodegradation of Spirodiclofen by Bacillus sp. Isolated from Savannah and Citrus Fruits Soils

Spirodiclofen, an extensively used insecticide/acaricide in fruit crops to mitigate pest-related losses, poses environmental and health risks due to its high toxicity and slow natural biodegradation. To mitigate this problem, bioremediation emerges as a viable solution for eliminating toxic xenobiotics and safeguarding the environment and human diet. In this study, an optimal bioremediation conditions was achieved using Bacillus sp. 6F, isolated from Savannah soil, and the Taguchi factorial experimental design (peptone G, pH 5, 40 ºC, 200 rpm). This optimized approach resulted in the biodegradation of 88% of spirodiclofen (100 mg L⁻¹) within 3 days, while Bacillus sp. CSA-21, isolated from citrus fruits soil, achieved a remarkable 93% degradation in just 2 days. Additionally, under these optimized conditions, 89% of the main metabolite M1, formed during spirodiclofen biodegradation, was effectively remediated within 3 days. Liquid chromatography tandem-mass spectrometry (LC–MS/MS) identified ten metabolites (M1-M10) produced during the spirodiclofen /M1 biodegradation process. This study presents an efficient, and fast decontamination protocol, marking a significant advancement in addressing spirodiclofen persistence in the environment.