Extension of Sphingobium sp. BHC-A to a 2,4,5-trichlorophenoxyacetic acid mineralizing strain by metabolic engineering

• Transfer of the upstream pathway for 2,4,5-T to 2,5-DCHQ into BHC-A.
• Engineered strain BHC-Ae degraded 2,4,5-T to 2,5-DCHQ.
• BHC-Ae mineralized 2,5-DCHQ through γ-HCH downstream degradation pathway.

The gene cassette encoding for TftAB and TftCD proteins was integrated into the 16srDNA gene of the γ-hexachlorocyclohexane (γ-HCH) mineralizing strain Sphingobium sp. BHC-A by homologous recombination. The recombinant γ-HCH mineralizing strain may degrade 2,4,5-trichlorophenoxyacetic acid at a rate of 250 nmol mg [protein]−1 h−1, and the generated intermediate 2,5-dichlorohydroquinone may be further mineralized through γ-HCH downstream degradation pathway.