Effective mycoremediation coupled with bioaugmentation studies: An advanced study on newly isolated Aspergillus sp. in Type-II pyrethroid-contaminated soil.

The intensive application of type-II pyrethroid worldwide in agricultural and residential practices potentially contributes to soil and water pollution, raising various concerns about environmental and public health. In the present study, robust fungus (strain PYR-P2) with high pyrethroids degradation potential was isolated from pesticide-contaminated soil. The strain was identified based on morphology and molecular characteristics, as Aspergillus sp. The screening of the transforming ability of strain PYR-P2 was evaluated in minimal salt media (MSM), where the fungus utilized up to 500 mg L of pyrethroid mixture (cypermethrin (CYP), cyfluthrin (CYF), cyhalothrin (CYH)). With this in view, central composite design (CCD) with three independent variables (pH, temperature, and initial concentration) was employed to identify the optimal conditions for achieving maximum pyrethroid removal. Under optimal conditions, strain PYR-P2 was implemented for the bioaugmentation studies in natural and sterile soil (NS/SS) systems spiked with pyrethroid (single and mixture) at a concentration of 100 mg kg. The highest pyrethroid removal percentages were observed in fungally augmented NS, accompanied by a decrease in pyrethroid half-life (t). Herein, the observed half-life (t) of pyrethroids in the fungally augmented NS varied between 1.48 and 2.69 d, with equally good values recorded in SS as 1.65-3.10 d. Taken together, the mycoremediation study employing fungal (strain PYR-P2) augmentation under optimized conditions represents an efficient strategy to restore pyrethroid-contaminated soil.