Figure 2.

Influence of oxygen, carbon sources, and growth phase on the transcription of the C4-dicarboxylate transporter genes as measured by real-time RT-PCR. (A) Transcript fold difference of the dcuA, dcuB, dcuC, dcuC2, and dctA genes in logarithmic phase grown wild-type C. jejuni (10 h) at 10% O₂ compared to 16 h at 0.3% O₂. (B) The effect of adding various carbon sources to the HI culture medium on the transcription of the C4-dicarboxylate genes. Hereto total RNA was isolated from wild-type grown in HI or HI with 25 mM serine, aspartate, fumarate, or succinate for 10 h. (C) Influence of the growth phase on the transcription of the C4-dicarboxylate genes as estimated for wild-type bacteria by real-time RT-PCR. Total RNA was extracted from logarithmic (10 h), or stationary (20 h) phase cultures. Fold change relative to the transcription levels was calculated using the arithmetic formula (2^−ΔΔCt). The gyrA gene was used as normalization gene. Data of four independent experiments with two independent preparations of RNA are presented as mean values ± standard deviation, ^**P < 0.01.