FIG. 5.

Expression of the ndnR, nadA, nadC, nadS, and cgR_1149 genes in response to nicotinate. (A) The C. glutamicum wild-type strain was cultured in minimal BT medium for 4 h, and then the culture was supplemented with nicotinate to the final concentration of 41 μM. The levels of ndnR (white rectangles), nadA (white circles), nadC (white triangles), nadS (white diamonds), and cgR_1149 (black rectangles) mRNAs in the cells 0, 3, 6, 9, and 12 min after the nicotinate supplementation were determined by quantitative RT-PCR. The mRNA levels are presented relative to the value attained using cells immediately before nicotinate supplementation (0 min). The values represent the means from three independent cultivations with standard errors. (B) C. glutamicum wild-type strain carrying the ndnR promoter-lacZ (PndnR-lacZ) fusion in the chromosome was cultured in minimal BT medium supplemented with nicotinate at 0, 0.041, 0.41, 4.1, 41, and 410 μM. The β-galactosidase activity in the exponentially growing cells was measured in Miller units (MU). The values represent the mean results from three independent cultivations, with standard errors.