Rapid elimination of dicarboximide fungicides and their metabolite 3,5-dichloroaniline from soils by immobilized bacterial consortia
Yibo Dong, Qiuping Wang, Jiaohong Li, Wanping Zhang, Xiaomao Wu
Abstract
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 °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.