Conversion of phenol to glutamate and proline in Corynebacterium glutamicum is regulated by transcriptional regulator ArgR.
This paper reports a novel integrated metabolic pathway of amino acid production through the utilization of phenol in Corynebacterium glutamicum. In the presence of 8.5 mM phenol, the level of glutamate and proline production increased up to 1.2- and 14.7-fold, respectively, compared to the control condition. In addition, their productivities increased 1.6- and 20-fold in the culture medium using phenol as the sole carbon source with 72 microM FeSO(4) as iron supplementation. Chromatin immunoprecipitation assay showed that the DNA-binding affinity of ArgR as a transcriptional repressor to the upstream of gltB and gdh gene was reduced significantly in the presence of 8.5 mM phenol. In addition, the DNA-binding affinity of ArgR to the upstream of gltB and gdh gene by iron supplementation was severely reduced, more than that under only 8.5 mM phenol. These results are consistent with those showing an increase in the mRNA levels of the two genes in the presence of 8.5 mM phenol and iron supplementation. Overall, iron enhances the biotransformation to glutamate and proline from phenol because of the regulated transcriptional levels. Furthermore, the biotransformation of phenol to glutamate and proline probably occurs through an interaction between ArgR and the gltB and gdh genes.
Lee
Soo Youn
SY
Department of Bioprocess Engineering, Chonbuk National University, 664-14 Duckjin-dong, Jeonju, South Korea.
Kim
Yang-Hoon
YH
Min
Jiho
J
D001426:Bacterial Proteins / Q000502:physiology*; D001711:Biotransformation; D047369:Chromatin Immunoprecipitation; D048230:Corynebacterium glutamicum / Q000378:metabolism*; D004269:DNA, Bacterial / Q000378:metabolism; D005296:Ferrous Compounds / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D018698:Glutamic Acid / Q000378:metabolism*; D019800:Phenol / Q000378:metabolism*; D011392:Proline; D011485:Protein Binding; D012097:Repressor Proteins / Q000502:physiology*
C087018:ArgR protein, Bacteria; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D005296:Ferrous Compounds; D012097:Repressor Proteins; D019800:Phenol; C020748:ferrous sulfate; D018698:Glutamic Acid; D011392:Proline