Fig 2.

Transcriptional analyses of genDFM, genR, and genKH of strains RES167 and RES167 ΔgenR in response to Glu (glucose), GEN, and 3-HBA. (A and B) qRT-PCR analyses examining the transcription of genDFM, genR, and genKH (indicated as DFM, R, and KH, respectively, on the x axis) in strains RES167 and RES167 ΔgenR. RNA samples were isolated from strains RES167 and RES167 ΔgenR induced on MM with 2 mM Glu, GEN, or 3-HBA overnight as described in Materials and Methods. Cultures grown on MM with GEN or 3-HBA were collected for RNA isolation. The levels of gene expression in each sample were calculated as the fold expression ratio after normalization to 16S rRNA gene transcript levels. The values are averages of two independent RT-qPCR experiments. Error bars indicate standard deviations. (C and D) β-Galactosidase activity driven by genDFM, genR, and genKH promoters. Strains RES167 and RES167 ΔgenR, both containing pZWHJ006, pZWHJ007, and pZWHJ008, were grown in triplicate in BHIBM and transferred into MM at a 1.0% inoculum containing 2 mM Glu, GEN, or 3-HBA for induction of β-galactosidase activity overnight. The mutant RES167 ΔgenR was first grown in BHIBM until mid-log phase and then harvested and transferred to MM for induction of β-galactosidase activity. β-Galactosidase activity was assessed using a Miller assay. The data are derived from at least three independent measurements, and error bars indicate standard deviations.