Fig. 4.

Expression of the ldhA and pyk2 genes in C. glutamicum. a Identification of the co-transcription of ldhA and pyk2 in the ldhA-pyk2 cluster using RT-PCR. The C. glutamicum WT strain was cultured in minimal medium with glucose under aerobic conditions. The templates used for the PCR were as follows: lanes 1 and 4, total RNA reverse transcribed without reverse transcriptase; lanes 2 and 5, genomic DNA; and lanes 3 and 6, cDNA. The fragments in lanes 1, 2 and 3 were amplified using the primers WZ1181/WZ868 for rpoB. In addition, the primers WZ1171 and WZ1156 were used for the ldhA-pyk2 region in lanes 4, 5 and 6. b The relative transcription levels of the pyk1, pyk2 and ldhA genes were analyzed by qRT-PCR. Total RNA was isolated from WT cells harvested at the exponential phase under aerobic conditions and at 3 h cultivation under oxygen-deprived conditions. The expression levels of pyk1, pyk2 and ldhA under different conditions were compared against the expression of pyk1 under aerobic conditions (=1). The mean values from at least three independent cultures are shown with the standard deviations