Genomic Analysis and Identification of Catabolic Pathways for Aromatic Compounds in Corynebacterium glutamicum

Abstract

The catabolism of aromatic compounds in Corynebacterium glutamicum was investigated by genome data mining and by experimental analysis. Results indicated that C. glutamicum assimilated different aromatic compounds such as phenol, p-cresol, benzoate, 4-hydroxybenzoate, vanillate, vanillin, resorcinol, 3,5-dihydroxytoluene and 2,4-dihydroxybenzoate. Genome data indicated, and enzyme assays confirmed; the existence of multiple ring-cleavage pathways for the catabolism of central aromatic intermediates; the protocatechuate and catechol branches of the -ketoadipate pathway, two similar hydroxyquinol pathways and the gentisate pathway. Two putative hydroxyquinol 1,2-dioxygenase genes (ncg11113 and ncg12951) were cloned and functionally identified in Escherichia coli. The genes encoding enzymes for the conversion of phenol, benzoate, 3-hydroxybenzoate, 4-hydroxybenzoate and vanillate in the central -ketoadipate pathways were mapped on the chromosome of C. glutamicum. A unique 30-kb (approximately 1% of the entire genome) catabolic island that channels the degradation of various aromatic compounds was mapped to position 2525-2555 kb of the genome. The global analysis and characterization of aromatic degradation pathways provided new insights into the metabolic ability of C. glutamicum in addition to its well-known ability to produce various amino acids and vitamins.

Genome-wide investigation of aromatic acid transporters in Corynebacterium glutamicum

“…In contrast to the location of all necessary genes for the protocatechuate branch of this pathway in the bketoadipate metabolic island, the putative transporter gene, ncgl1031, is located elsewhere in the genome. The ncgl2922 gene is located in another genetic cluster, and this gene has been previously shown to be necessary for 3-hydroxybenzoate and gentisate assimilation (Shen et al, 2005b). The ncgl2953 gene is located in one of the two genetic clusters (ncgl1110-ncgl1113 and ncgl2950-ncgl2953) that have recently been determined to be involved in resorcinol and hydroxyquinol degradation (Huang et al, 2006).…”

Molecular characterization of a eukaryotic-like phenol hydroxylase from <i>Corynebacterium glutamicum</i>

“…Escherichia coli strains were grown aerobically on a rotary shaker at 37°C in Luria-Bertani (LB) broth or on LB agar plates. C. glutamicum strains were routinely grown in LB medium or in mineral salts medium (MSM) supplemented with glucose or aromatic compounds as a carbon source on a rotary shaker (180 rpm) at 30°C (Shen et al, 2005a). For the generation of mutants and maintenance of C. glutamicum, BHIS medium (brain heart broth with 0.5 M sorbitol) was used.…”

“…Key Words: Corynebacterium glutamicum; oligomerization; phenol hydroxylase; site-directed mutagenesis Corynebacterium glutamicum, a well-known Gram-positive industrial bacterium widely applied in amino acids and nucleotides production, was recently reported to assimilate various phenolic compounds such as phenol, vanillin, ferulic acid, benzoate, 4-hydroxybenzoate, 2,4-dichlorobenzoate, and other aromatic compounds (Qi et al, 2007;Shen et al, 2004Shen et al, , 2005a. Indeed, C. glutamicum has recently been successfully used for the large-scale remediation of phenol-contaminated soil and water (Lee et al, 2010a;Shen and Liu, 2005).…”

“…This newly defined amino acid production processes provide an alternative pathway in bioremediation/bioconversion of phenolic pollutants in C. glutamicum. Although most of the pathways and enzymes involved in the assimilation of aromatic compounds have been characterized in C. glutamicum (Shen et al, 2005a(Shen et al, , 2012, no functional or biochemical information about phenol hydroxylase in the genus Corynebacterium has been reported so far. In this paper, we have biochemically identified the gene phe encoding a single-component, eukaryote-like phenol hydroxylase in C. glutamicum.…”

The LacI/GalR family transcriptional regulator UriR negatively controls uridine utilization of Corynebacterium glutamicum by binding to catabolite-responsive element (cre)-like sequences

“…Corynebacterium glutamicum is a Gram-positive soil bacterium, able to sense and utilize a large variety of carbon and energy sources so as to adapt to constantly changing environmental conditions (Eikmanns, 2005;Shen et al, 2005;Yukawa et al, 2007). This ability is mediated by a diverse metabolism that underlies a complex regulation on the transcriptional level Han et al, 2007).…”