Expression and characterization of a recombinant 2,3-dihydroxybiphenyl-1,2-dioxygenase from Pseudomonas

摘要

The 2, 3-dihydroxybiphenyl-1,2-dioxygenase, which can degrade the 2,3-dihydroxybiphenyl, was encoded by a synthesized PsbphCI gene. The PsbphCI gene was transformed into Escherichia coli and the encoding protein purified, had a molecular mass of ～32 kDa as determined by SDS-PAGE. The optimum pH for the purified enzyme at 20°C was 9.0, and the optimal temperature at pH 8.0 was 30°C. Subsequently, the PsbphCI gene was transformed into Pseudomonas putida sp. to verify the degradation of 2,3-dihydroxybiphenyl by HPLC. The transgenic EG11 strain degraded 65.20% of the 2,3-DHBP after 2 minutes at 30°C, while the wild-type EG11 strain degraded only 37.75%. This study provides guidance for the cultivation of bioengineered biphenyl/PCBs-degrading bacteria which can be applied to the biodegradation of environmental biphenyl/PCBs contamination.