The XylR/NtrC-type regulator CbsR positively regulates upstream pathway of chlorobenzene degradation in Pandoraea pnomenusa.

This article focuses on the regulatory mechanisms controlling chlorobenzene degradation in the bacterium Pandoraea pnomenusa MCB032. It demonstrates that the XylR/NtrC-type regulator CbsR positively regulates the transcription of the cbsFAaAbAcAdB operon, which encodes enzymes for the upstream pathway converting chlorobenzene to 3-chlorocatechol, while the LysR-type regulator ClcR activates the clcABCDE operon responsible for the downstream 3-chlorocatechol degradation pathway. Experimental approaches including gene knockout, RT-PCR, primer extension, and electrophoretic mobility shift assays confirmed that CbsR binds promoter regions of both the cbs operon and its own operon, enhancing transcription in response to chlorobenzene. These findings elucidate the transcriptional regulation underlying chlorobenzene catabolism in strain MCB032, contributing to its effectiveness in bioremediation of chlorobenzene-contaminated environments.