Biodegradation of Fipronil: Transformation Products, Microbial Characterisation and Toxicity Assessment

Fipronil is a highly active, broad spectrum insecticide with increasing and wide use. The degradation of fipronil was studied in Brazilian soil under oxic anoxic conditions. Under conditions, the half-life 16.9 days, sulfone as main metabolite, no further during 30 days incubation. This accompanied by an increase bacterial archaeal ammonia oxidizers, well denitrifiers, microorganisms related to Sphingomonas. 15.7 for obtained, sulphide primary at lower concentrations, these metabolites 90 In complete iron-reducers oxidizers selection that are uncultured Clostridiales (family VIII). Sulphate reducers methanogens most microbial community were not affected its metabolites. Toxicity evaluation, using vitro effect-based CALUX assays confirmed have similar toxic potency compared parent compound fipronil. Therefore, potential (eco)toxicity does seem decrease upon degradation.