Enhancement of carbofuran degradation by immobilized Bacillus sp. strain DT1

Abstract

The widespread application of carbofuran has raised increasing concerns about health damage and environmental pollution. To degrade carbofuran in liquid and soil media, Bacillus sp. strain DT1 was isolated from soil. The isolated bacterial strain used the compound as a sole source of carbon and energy. Using rice straw as a material for bacteria immobilization resulting in 97.5% of the insecticide was degraded in a biofilm-batch reactor at the 3rd cycle, which was about 20% higher than using glass slides for immobilization. The chemical degradation in soils by bacteria immobilized in rice straw was also from 12.5% to 19.8% higher than by free counterparts. Furthermore, the dissipation rates in the previously-treated soils were higher than those in the untreated soils. Besides, the degradation of carbofuran by Bacillus sp. DT1 produced 3-hydroxycarbofuran, carbofuran 7-phenol and 2-hydroxy-3-(3-methypropan-2-ol) phenol as intermediate products. These findings demonstrated that Bacillus sp. DT1 immobilized in rice straw has a high potential for bioaugmentation of carbofuran in biofilm-batch reactor and in soils.