RT Journal Article SR Electronic(1) A1 Rehm, Nadine A1 Georgi, Tobias A1 Hiery, Eva A1 Degner, Ursula A1 Schmiedl, Alfred A1 Burkovski, Andreas A1 Bott, MichaelYR 2010 T1 l-Glutamine as a nitrogen source for Corynebacterium glutamicum: derepression of the AmtR regulon and implications for nitrogen sensing JF Microbiology, VO 156 IS 10 SP 3180 OP 3193 DO https://doi.org/10.1099/mic.0.040667-0 PB Microbiology Society, SN 1465-2080, AB Corynebacterium glutamicum, a Gram-positive soil bacterium employed in the industrial production of various amino acids, is able to use a number of different nitrogen sources, such as ammonium, urea or creatinine. This study shows that l-glutamine serves as an excellent nitrogen source for C. glutamicum and allows similar growth rates in glucose minimal medium to those in ammonium. A transcriptome comparison revealed that the nitrogen starvation response was elicited when glutamine served as the sole nitrogen source, meaning that the target genes of the global nitrogen regulator AmtR were derepressed. Subsequent growth experiments with a variety of mutants defective in nitrogen metabolism showed that glutamate synthase is crucial for glutamine utilization, while a putative glutaminase is dispensable under the experimental conditions used. The gltBD operon encoding the glutamate synthase is a member of the AmtR regulon. The observation that the nitrogen starvation response was elicited at high intracellular l-glutamine levels has implications for nitrogen sensing. In contrast with other Gram-positive and Gram-negative bacteria such as Bacillus subtilis, Salmonella enterica serovar Typhimurium and Klebsiella pneumoniae, a drop in glutamine concentration obviously does not serve as a nitrogen starvation signal in C. glutamicum. , UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.040667-0