Transcriptional profiling of Corynebacterium glutamicum metabolism during organic acid production under oxygen deprivation conditions.
A transcriptional profiling of the metabolism of Corynebacterium glutamicum under oxygen deprivation conditions is reported. It was observed that the glucose consumption rate per cell when C. glutamicum cells were incubated under oxygen deprivation conditions was higher than that achieved by cells incubated under aerobic growth conditions. Furthermore, DNA microarray and quantitative RT-PCR analyses revealed that the genes of several key enzymes of the glycolytic and organic acid production pathways, including gapA, pgk, tpi, ppc, ldhA and mdh, were significantly upregulated under oxygen deprivation conditions. The corresponding enzymic activities consistently correlated with the regulation patterns of the genetic expression observed at the transcriptional level. Studies of lacZ fusions with the gapA, ldhA and mdh genes indicated not only that these genes are strongly induced at the onset of the stationary phase under aerobic growth conditions, but also that high expression levels are maintained under oxygen deprivation conditions. These results indicate that the genetic expression of several key metabolic enzymes in C. glutamicum cells incubated under oxygen deprivation conditions is chiefly regulated at the transcriptional level. The physiological consequence of the observed increased transcription under oxygen deprivation conditions is an increased rate of carbon source consumption, which is accompanied by a concomitant increase in organic acid production.
Inui
Masayuki
M
Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan.
Suda
Masako
M
Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan.
Okino
Shohei
S
Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan.
Nonaka
Hiroshi
H
Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan.
Puskás
László G
LG
Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan.
Vertès
Alain A
AA
Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan.
Yukawa
Hideaki
H
Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan.
D000693:Anaerobiosis; D019677:Artificial Gene Fusion; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D002264:Carboxylic Acids / Q000378:metabolism*; D048230:Corynebacterium glutamicum / Q000235:genetics* / Q000378:metabolism*; D004798:Enzymes / Q000235:genetics; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D017930:Genes, Reporter; D005947:Glucose / Q000378:metabolism; D053858:Metabolic Networks and Pathways / Q000235:genetics; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D012329:RNA, Bacterial / Q000096:biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D001616:beta-Galactosidase / Q000032:analysis / Q000235:genetics
D001426:Bacterial Proteins; D002264:Carboxylic Acids; D004798:Enzymes; D012329:RNA, Bacterial; D012333:RNA, Messenger; D001616:beta-Galactosidase; D005947:Glucose