Abstract

Pseudomonas sp. strain S-47 can grow on 4-chlorobenzoate (4CBA) and transform 4CBA to 4-chlorocatechol (4CC) under aerobic conditions, which is subsequently degraded to produce 2-hydroxypent-2, 4-dienoate (2H-2,4DA). The upper steps for conversion of 4CBA to 4CC are recognized to be conducted by the benzoate-1,2-dioxygenase (B12O) system encoded by benABC and benD. The ensving meta-cleabage reaction of 4CC is catalyzed by catechol 2,3-dioxygenase(C23O) encoded by the xylE gene. The benABCD and the xylE genes were cloned from the chromosome of Pseudomonas sP. S-47 into pCS1(48.7kb), pCS101(24.4kb), pCS201(17.7kb), and pCS202(6.7kb) recombinant plasmids, and were well ecpressed in E. coli XL1-Blue host cells. The PstI-insert (4.0kb) of pC202 was found to contain the benABCD and cylE genes and to have 2 EcoRV, 1 SphI, and 3 SacII restriction sites.

• Keywords: benABCD; xylE 4-chlorobenzoate; 4-Chlorocatechol; dioxygenase; Pseudomonas sp. S-47