Construction of a genetically engineered microorganism for phenanthrene biodegradation

The bacterium Pseudomonas sp. CGMCC2953, isolated from oil-polluted soil, was used as a recipient for a biodegradative gene encoding catechol 2,3-dioxygenase (C23O), which was successfully cloned into the plasmid pK4 derived from pRK415 with a broad host range. The apparent phenanthrene biodegradation parameters of the recombinant microorganism (Pseudomonas sp. CGMCC2953-pK) were determined and compared with those of the wild type. As the key enzyme of phenanthrene degradation, C23O, could be expressed constitutively in the recombinant strain, Pseudomonas sp. CGMCC2953-pK showed an increased ability to degrade phenanthrene. The excessive production of C23O in Pseudomonas sp. CGMCC2953-pK could serve as an effective approach to construct genetically engineered microorganisms for the bioremediation of environmental contaminations.