Rapid Elimination of Dicarboximide Fungicides and Their Metabolite 3,5-Dichloroaniline from Soils by Immobilized Bacterial Consortia

The elimination of dicarboximide fungicides (DFs) and their metabolite 3,5-dichloroaniline (3,5-DCA) from polluted sites has a heightened concern considering their bioaccumulation and toxic health risks in humans and animals. In this study, the consortia of Providencia stuartii JD and Brevundimonas naejangsanensis J3 immobilized in a charcoal-alginate-chitosan carrier potently enhanced the degradation of dimethachlon + iprodione (D + I), iprodione + procymidone (I + P), dimethachlon + procymidone (D + P), dimethachlon + iprodione + procymidone (D + I + P), and 3,5-dichloroaniline in liquid cultures as contrasted to their free consortia. The optimized degradation parameters of immobilized JD + J3 were ascertained to be pH 7, 30 degrees C, 140 mg/mL immobilized JD + J3 and 50 mg/L mixed DFs or 3,5-DCA. Moreover, immobilized JD + J3 consortia exhibited the outstanding reusability and storage stability. Immobilization consortia of JD + J3 effectively accelerated the degradation of four mixtures of DFs mentioned above in field yellow soil and brown soil compared with the natural dissipation, and notably shortened their half-lives by 10.23-11.08 folds and 9.87-11.76 folds, respectively. Meanwhile, immobilized JD + J3 consortia also emerged a conspicuous enhancement effect for eliminating 3,5-dichloroaniline deriving from DFs in field soils. This work provides a new insight and strategy for the in situ rapid bioremediation of soils in agricultural areas polluted by mixed xenobiotics producing more toxic and persistent metabolites. (c) 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).