Transfer of the gene encoding the NapA acid phosphatase of Morganella morganii to a Burkholderia cepacia strain

A composite plasmid was constructed using the broad-host-range vector pRK29 3 and the plasmid pPM9, the latter one harbouring a gene encoding the Nap A acid phosphatase from At. morganii. The recombinant construction was trans formed and expressed in E. coli MC1061. Transformant clones were selected a nd characterized, showing that the relative orientation of both original pl asmids with respect to each other affected the expression of the gene, with one of the plasmids (pT4) expressing significantly lower values of activit y than the opposite orientation construction (pT5). Zymograms developed to detect acid phosphatase activity also corroborated the gene expression in t he E. coli host. The genetic constructions (pT4 and pT5) were transferred. to B. cepacia IS-16 by conjugation. The same effect of the original plasmid orientation in the construction was corroborated in the B. cepacia IS-16 s train. Compared with the strain lacking the recombinant plasmid, no signifi cant improvement of cell-bound enzymatic activity was achieved by the excon jugant harbouring pT5. However, a significant increase in the extracellular enzyme activity was detected in the recombinant strains. No metabolic load due to the presence of the recombinant plasmid was detected in both E. col i and Burkholderia hosts.