• Journal of Microbiology and Biotechnology
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• v.25 no.4
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• pp.452-458
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• 2015

The biocatalytic efficiency of recombinant Corynebacterium glutamicum ATCC 13032 expressing the secondary alcohol dehydrogenase of Micrococcus luteus NCTC2665 was studied. Recombinant C. glutamicum converts ricinoleic acid to a product, identified by gas chromatography/mass spectrometry as 12-ketooleic acid (12-oxo-cis-9-octadecenoic acid). The effects of pH, reaction temperature, and non-ionic detergent on recombinant C. glutamiucm whole cell bioconversion were examined. The determined optimal conditions for production of 12-ketooleic acid are pH 8.0, 35℃, and 0.05 g/l Tween80. Under these conditions, recombinant C. glutamicum produces 3.3 mM 12-ketooleic acid, with a 72% (mol/mol) maximum conversion yield, and 1.1 g/l/h volumetric productivity in 2 h; and 3.9 mM 12-ketooleic acid, with a 74% (mol/mol) maximum conversion yield, and 0.69 g/l/h maximum volumetric productivity in 4 h of fermentation. This study constitutes the first report of significant production of 12-ketooleic acid using a recombinant Corynebacterium glutamicum-based biocatalyst.

• Microbiology and Biotechnology Letters
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• v.17 no.6
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• pp.552-555
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• 1989

A 150-fold purified preparation of NADPH-specific glutamate dehydrogenase of Corynebacterium glutamicum (1) was used for the determination of kinetic parameters of the substrates, NADPH, NH$_4$Cl, and $\alpha$-ketoglutarate in the direction of glutamate synthesis. The kinetic constants determined from this study suggest a biosynthetic role for the enzyme, Based on the analysis of the result derived from initial velocity, the reaction mechanism was postulated to be ordered addition with NADPH as a first substrate to bind in the forward direction. Of the several metabolites tested for a possible function in the regulation of glutamate dehydrogenase activity, only malate and citrate were appeared to have an appreciable influence on the enzyme, Potassium chloride showed to be the most effective for the enzyme activity.

• Microbiology and Biotechnology Letters
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• v.45 no.3
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• pp.271-275
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• 2017

The expression of Deinococcus radiodurans dr1558 and pprM genes was examined for enhanced lysine production in recombinant Corynebacterium glutamicum. These genes are known to confer high tolerance to pH and osmotic shock in Escherichia coli. D. radiodurans dr1558 and pprM genes were expressed in C. glutamicum by using 6 synthetic promoters of different strengths, to evaluate the effect of expression efficiency on lysine production. Recombinant C. glutamicum expressing DR1558 under the L26 and I64 promoters showed higher lysine production than that expressing DR1558 under other promoters. Similarly, recombinant C. glutamicum expressing PprM under same promoters (L26 and I64) showed a higher increase in lysine production compared to that expressing PprM under other promoters. In the absence of $CaCO_3$ in the medium, the expression of DR1558 or PprM also increased lysine concentration in C. glutamicum depending on the promoter used. Together, these results suggest that genes involved in radiation tolerance in D. radiodurans can be used to enhance production of amino acids and their derivatives.

• Microbiology and Biotechnology Letters
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• v.47 no.1
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• pp.78-86
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• 2019

Recombinant Corynebacterium glutamicum producing N-acetylglucosamine (GlcNAc) was constructed by metabolic engineering. To construct a basal strain producing GlcNAc, the genes nagA, nagB, and nanE encoding N-acetylglucosamine-6-phosphate deacetylase, glucosamine-6-phosphate deaminase, and N-acetylmannosamine-6-phosphate epimerase, respectively, were sequentially deleted from C. glutamicum ATCC 13032, yielding strain KG208. In addition, the genes glmS and gna1 encoding glucosamine-6-phosphate synthase and glucosamine-6-phosphate N-acetyltransferase, which originated from C. glutamicum and Saccharomyces cerevisiae, respectively, were expressed in several expression vectors. Among several combinations of glmS and gna1 expression, recombinant cells expressing glmS and gna1 under control of the ilvC promoter produced 1.77 g/l of GlcNAc and 0.63 g/l of glucosamine in flask cultures.

• Journal of Microbiology and Biotechnology
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• v.11 no.2
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• pp.294-301
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• 2001

The effects of including glycine and isonicotinic acid hydrazide (INH) in the growth medium (Luria broth, LBG) on the subsequent lysozyme-imduced protoplast formation and transformation efficiency of Corynebacterium glutamicum were studied. The transformation efficiency of C. glutamicum AS019 increased up to 100-fold as the ocncentrationof glycine in the media increased from 0% to 5% (w/v), relative to cells grown in the absence of glycine. The presence of 5 mg/ml INH in the growth medium led to a further 10-fold increase in transformation efficiency. In addition, this transformation protocol was successfully applied to other strains of C. glutamicum. Both chemicals affected the mycolic acid attachment to the cell surface of C. glutamicum, when INH, the relative percentage of fatty acids of AS019 to the total lipids (mycolic acid plus fatty acids) decreased from 76.9% (in LBG) to 72.9% (in LBG-2% glycine) and 66.4% (in LBG-8 mg InG/ml), thereby suggeting that these chemicals also inhibit fatty acid synthesis.

• Journal of Microbiology and Biotechnology
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• v.26 no.8
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• pp.1404-1408
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• 2016

In recent years, foot-and-mouth disease has occurred in all parts of the world. The animals with the disease are buried in the ground; therefore, their concentration could affect ground or groundwater. Moreover, the complete degradation of carcasses is not a certainty, and their disposal is important to prevent humans, livestock, and the environment from being affected with the disease. The treatment of Corynebacterium glutamicum is a feasible method to reduce the risk of carcass decomposition affecting humans or the environment. Therefore, this study aimed to investigate the effect of C. glutamicum on the soil environment with a carcass. The composition of amino acids in the soil treated with C. glutamicum was generally higher than those in the untreated soil. Moreover, the plant root in the soil samples treated with C. glutamicum had 84.0% amino acids relative to the standard value and was similar to that of the control. The results of this study suggest the possibility to reduce the toxicity of a grave land containing animals with this disease.

• Korean Journal of Veterinary Service
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• v.40 no.1
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• pp.53-59
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• 2017

Foot and mouth disease (FMD) is highly infectious disease of cloven-hoofed animals, particularly problematic in cattle, sheep, pigs and goats for economic reasons. Last FMD outbreak in February, 2017 caused tremendous social and economical impacts. The Korean FMD policy aims to vaccinate intact animals and euthanize and bury infected animals to prevent the disease spread. However, there was a problem that the buried livestock did not decompose after several years. Therefore, the study was purposed to investigate the effect of Corynebacterium glutamicum and Bacillus licheniformis on the degradation of buried cow carcasses and on the soil condition; such as temperature, decomposition course of carcasses, composition of amino acids in the soil around carcasses, and plant root elongation to measure soil conditions. As a result, the composition of amino acids in the soil treated with C. glutamicum and B. licheniformis was generally higher than those in the untreated soil. Plant roots in soil treated with C. glutamicum and B. licheniformis grew longer than in non-treated soil. The results suggested that the toxic effect on a grave land buried with FMD infected livestock is reduced when treated with C. glutamicum and B. licheniformis in regard of odor reduction, promoted decaying process, and soil fertilization.

• KSBB Journal
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• v.5 no.2
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• pp.125-131
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• 1990

Microbial production of L-phenylalanine using Corynebacterium glutamicum ATCC 21674, a tyrosine auxotroph resistant to aromatic amino acid analogues, has been studied and kinetic analysis was performed. Even though the strain was reported as a tyrosine auxotroph, it produced tyrosine and was able to grow on the minimal medium where no tyrosine was present. The average specific growth rate at the exponential growth phase was 0.087 hr-1. There was a dissociation of growth from the formation of the product. Linear correlation between biomass production and total CO2 production was obtained. The relationship between CO2 evolution rate and sugar consumption rate was also found to be linear.

• Journal of Microbiology and Biotechnology
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• v.7 no.6
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• pp.435-437
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• 1997

The role of $Ca^{2+}$ in making functional malate synthase in Corynebacterium glutamicum was investigated using the cloned DNA coding for the enzyme. Introduction of cloned aceB into C. glutamicum overexpressed malate synthase as judged by SDS-PAGE. However, the increase in enzyme activity of the expressed malate synthase did not match the level of overexpression observed in SDS-PAGE. Addition of $Ca^{2+}$ to the growth medium specifically increased the activity. The malate synthase could be stained with ruthenium red in a $Ca^{2+}$-specific manner. This agrees with the previous observation which reported a potential $Ca^{2+}$-binding domain in the N-terminal region of the protein.

• Journal of Microbiology and Biotechnology
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• v.17 no.2
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• pp.187-194
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• 2007

In order to utilize different nitrogen sources and to survive in a situation of nitrogen limitation, microorganisms have developed sophisticated mechanisms to adapt their metabolism to a changing nitrogen supply. In this communication, the recent knowledge of nitrogen regulation in the amino acid producer Corynebacterium glutamicum is summarized. The core adaptations of C. glutamicum to nitrogen limitation on the level of transcription are controlled by the global regulator AmtR. Further components of the signal pathway are GlnK, a $P_{II}-type$ signal transduction protein, and GlnD. Mechanisms involved in nitrogen control in C. glutamicum regulating gene expression and protein activity are repression of transcription, protein-complex formation, protein modification by adenylylation, change of intracellular localization, and proteolysis.