Utilization of Phenol and Naphthalene Affects Synthesis of Various Amino Acids in Corynebacterium glutamicum

Abstract

This article reports multiple metabolic pathways of amino acid production via phenol and naphthalene use by Corynebacterium glutamicum. Biodegradation of phenol and naphthalene by C. glutamicum occurred in a mineral salt medium containing 1% yeast extract without any additional carbon sources. Among the amino acids synthesized via the TCA-cycle, glutamate synthesis increased in C. glutamicum supplemented with 8.5 mM phenol or with 4.2 mM naphthalene. Aspartate synthesis significantly increased when cultured with 4.2 mM naphthalene, and increased synthesis of threonine and histidine was observed only with the addition of phenol. In addition, synthesis of valine and leucine decreased considerably under both conditions. Moreover, the bioconversion of glutamate from phenol and naphthalene is regulated by a transcriptional regulator, FarR, at the transcription level of the gltBD and gdh genes. In this study, we found that the utilization of phenol and naphthalene enhances biosynthesis of several amino acids and that this mechanism is controlled by a transcriptional regulator.

Degradation and assimilation of aromatic compounds by Corynebacterium glutamicum: another potential for applications for this bacterium?

“…In phenol-grown cultures (8.5 mM), the production of glutamate and proline were 149.2 mM and 143.3 mM, 1.2 and 14.7 times higher, respectively, than the culture conditions without phenol, suggesting that the metabolic intermediates from phenol degradation fluxed into the central carbon metabolism and were used to produce glutamate and proline (Lee et al 2010a). When cultured with 4.2 mM naphthalene, aspartate and glutamate production also increased to 15.2 mM and 100.4 mM, 1.5-and 1.3-fold, respectively, compared to control (without naphthalene) (Lee et al 2010b). Much work is needed in the future to turn this into reality of the concept of using aromatic compounds as feedstock for bioproduction.…”

“…In contrast, its ability to utilize aromatic compounds is impressive. C. glutamicum grows on the following aromatic compounds: benzoate, phenol (Shen et al 2004), 3-hydrobenzoate, gentisate (Shen et al 2005b), protocatechuate, vanillate, 4-hydroxybenzoate, 4-cresol (Shen and Liu 2005;Qi et al 2007), resorcinol (Huang et al 2006), benzyl alcohol, 2,4-dihydroxybenzoate, 3,5-dihydroxytoluene (Shen et al 2005a), naphthalene (Lee et al 2010b), vanillin, ferulic acid (Merkens et al 2005), cinnamate, caffeate, and 4-coumarate (unpublished data). These compounds and their derivatives are channeled into central carbon metabolic pathways, as discussed in the following sections.…”

“…The discovery of mycothiol (MSH)-dependent gentisate pathway and the MSH-dependent maleylpyruvate isomerase C. glutamicum utilizes 3-hydroxybenzoate, gentisate, and naphthalene as carbon source for growth via the gentisate pathway (Shen et al 2005a;Lee et al 2010b) (Fig. 1).…”

Interaction of Transcriptional Repressor ArgR with Transcriptional Regulator FarR at the argB Promoter Region in Corynebacterium glutamicum

“…The construction of pEMBTL-SY0 carrying the argR coding region and pEMBTL-SY5 carrying the farR coding region were described in previous studies (Table 1) (13,14). pEMBTL-SY5 and pEMBTL-SY0, were used to transform E. coli BL21(DE3) cells by electroporation.…”

Bioremediation of 3,5-dinitrobenzoic acid and aniline by a Corynebacterium sp.

“…The knowledge of aromatic degradation and assimilation by this bacterium had been rarely explored until recently (Shen et al, 2012). C. glutamicum grows on the following aromatic compounds: benzoate, phenol (Shen et al, 2004), 3-hydrobenzoate, gentisate (Shen et al, 2005), resorcinol (Huang et al, 2006) and naphthalene (Lee et al, 2010). This paper focuses on the characterization of *Corresponding author.…”