A DNA fragment containing the pgdA gene (lmo0415) and its promoter was generated by PCR using oligonucleotides lmo0415-1 (59-AAGGATCCCACAATATGTTAGTTTTCAGGGG-39) and lmo0415-2 (59-AAGGATCCTTATTTCACCATTCTT-GAATCTG-39). The fragment was integrated into pCR-Blunt-II-TOPO (Invitrogen) and the construct was verified by sequencing. After digestion of the construct by BamHI, the fragment was purified on agarose gel and cloned into the integrative vector pPL2 [43] , previously digested by BamHI, constructing pOD98. The pOD98 was electroporated into DpgdA at 2,500 V, 200 V and 25 mF. Transformants were selected at 37uC on BHI agar containing chloramphenicol (7 mg/mL). The presence of the pgdA gene in the complemented strain was confirmed by PCR using oligonucleotides lmo0415-1 and lmo0415-2.