Fig. 6

GABA fermentation of gadB2-expressing C. glutamicum strains under P _dnaK promoter with different length and bicistronic architecture. a Cell growth, b glucose consumption, c GAD activity, d Glu production, e GABA production, f gadB2 transcription level. Squares PdnaK-B2, circles PdnaK(+1)-B2, triangles PdnaK(−1)-B2, empty squares in dotted line PdnaK(−2)-B2, empty circles in dotted line PdnaK(−3)-B2, empty triangles in dotted line PdnaK2SD-B2. White bars at 20 h, black bars at 40 h. Averages of three independent experiments are provided