FIG. 2.

Plasmids used in this study. (A) Diagram of mutagenic plasmid pMO9020. The region from nucleotides 683 to 3715 is the mutagenic cassette for deletion of qmoABC and DVU0851 genes by marker exchange mutagenesis. NcoI sites were used for Southern confirmation of the deletion. (B) pMO9072 vector constructed for complementation studies in SRB and pMO9072. The promoter aph(3′)-IIp is constitutively expressed and drives the expression of a gene placed in the multicloning site. The pBG1 segment is an endogenous cryptic plasmid from Desulfovibrio strain G20 (34) that allows for stable replication of plasmids in SRB. Unique restriction sites that can be used for the introduction of complementing DNA are shown. SpR, spectinomycin resistance.