Comparison of C. glutamicum growing with GABA as carbon source in the presence or absence of (NH4)2SO4.

γ-Aminobutyric acid (GABA) is a non-proteinogenic amino acid and widespread in nature from microorganisms to plants and animals. DNA microarray analysis revealed that the transcription of gabTDP was strongly increased in C. glutamicum wild type grown with GABA and urea compared to the same strain cultivated with glucose and urea. Remarkably, the presence of ammonia partially inhibited growth on GABA, and the reasons for it were also investigated in this study. The aim was to identify genes differentially expressed in Corynebacterium glutamicum ATCC13032 cultivated in CGXII minimal medium with GABA as carbon source either with or without ammonium because addition of ammonium caused a growth defect under these conditions. C. glutamicum ATCC 13032 was cultivated inCGXII medium with GABA as carbon source and either (NH4)2SO4 or K2SO4. The cells were harvested in the exponential growth phase at an OD600 of 5.