中国生物工程杂志

Benzoate dioxygenase gene（benABC）cluster was amplified from Pseudomonas sp.B3-1 DNA in vitro, using PCR techniques and directionally cloned into plasmid pLAFRJ. The recombinant plasmid was transformed into E．coli DH5α by electroporation, then mobilized into Pseudomonas sp.B3-1 by triconjugation. Selecting for the medium with Amp and Tc bioantics, the recombinant strain named Pseudomonas sp.B4 were obtained. After optimizing the fermentation conditions of this strain for producing catecho1，the optimized conditions were sodium benzoate 6.0 g/L, polypepton 2.5 g/L, pH6.0, incubated at 32℃and shaken at 200 rpm for 36 hour. Under these conditions，the catechol yield improved about 20% compared with the wild strain B3-1 and reached 0.7 mg/ml.