• Journal of Applied Biological Chemistry
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• v.48 no.4
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• pp.218-221
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• 2005

Nucleotide sequence of Brevibacterium flavum ptsG gene capable of complementing Escherichia coli ZSC113 mutations defective to glucose permease activity of phosphotransferase system was completely determined, and the gene product was compared with other glucose-specific enzyme II ($EII^{Glc}$). A ptsG gene of B. flavum consisted of open reading frame of 2,025 nucleotides putatively encoding polypeptide of 675 amino acid residues and TAA stop codon. Deduced amino acid sequence of B. flavum ($EII^{Glc}$) had high homology with ($EIIs^{Glc}$) of Corynebacterium glutamicum, C. efficiens, and B. lactofermentum. Arrangement of structural domains, IIBCA, of B. flanum ($EII^{Glc}$) protein was identical to that of EIIs belonging to glucose-phosphotransferase system.

• Journal of Microbiology and Biotechnology
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• v.5 no.5
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• pp.250-256
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• 1995

The ddh gene encoding meso-diaminopimelate (meso-DAP)-dehydrogenase (DDH) in Brevibacterium lactofermentum was isolated by complementation of the Escherichia coli dapD mutation. It was supposed from subcloning experiments and complementation tests that the evidence for DDH activity appeared in about 2.5 kb Xhol fragmented genome. The 2.5 kb Xhol fragment containing the ddh gene was sequenced, and an open reading frame of 960 bp encoding a polypeptide comprising 320 amino acids was found. Computer analysis indicated that the deduced amino acid of the B. lactofermentum ddh gene showed a high homology with that of the Corynebacterium glutamicum ddh gene.

• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.736-741
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• 2012

In this study, we analyzed the oxidative stress response of wblA ($\underline{w}$hi$\underline{B}$-$\underline{l}$ike gene $\underline{A}$, SCO3579), which was previously shown to be a global antibiotic down-regulator in Streptomyces coelicolor. Ever since a WblA ortholog named WhcA in Corynebacterium glutamicum was found to play a negative role in the oxidative stress response, S. coelicolor wblA has been proposed to have a similar effect. A wblA-deletion mutant exhibited a less sensitive response to oxidative stress induced by diamide present in solid plate culture. Using real-time RT-PCR analysis, we also compared the transcription levels of oxidative stress-related genes, including sodF, sodF2, sodN, trxB, and trxB2, between S. coelicolor wild type and a wblA-deletion mutant in the presence or absence of oxidative stress. Target genes were expressed higher in the wblA-deletion mutant compared with wild type, both in the absence and presence of oxidative stress. Moreover, expression of these target genes in S. coelicolor wild type was stimulated only in the presence of oxidative stress, suggesting that WblA plays a negative role in the oxidative stress response of S. coelicolor, similar to that of C. glutamicum WhcA, through the transcriptional regulation of oxidative stress-related genes.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.5
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• pp.237-251
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• 2002

The recent progress on metabolic systems engineering was reviewed based on our recent research results in terms of (1) metabolic signal flow diagram approach, (2) metabolic flux analysis (MFA) in particular with intracellular isotopomer distribution using NMR and/or GC-MS, (3) synthesis and optimization of metabolic flux distribution (MFD), (4) modification of MFD by gene manipulation and by controlling culture environment, (5) metabolic control analysis (MCA), (6) design of metabolic regulation structure, and (7) identification of unknown pathways with isotope tracing by NMR. The main characteristics of metabolic engineering is to treat metabolism as a network or entirety instead of individual reactions. The applications were made for poly-3-hydroxybutyrate (PHB) production using Ralstonia eutropha and recombinant Escherichia coli, lactate production by recombinant Saccharomyces cerevisiae, pyruvate production by vitamin auxotrophic yeast Toluropsis glabrata, lysine production using Corynebacterium glutamicum, and energetic analysis of photosynthesic microorganisms such as Cyanobateria. The characteristics of each approach were reviewed with their applications. The approach based on isotope labeling experiments gives reliable and quantitative results for metabolic flux analysis. It should be recognized that the next stage should be toward the investigation of metabolic flux analysis with gene and protein expressions to uncover the metabolic regulation in relation to genetic modification and/ or the change in the culture condition.

• KSBB Journal
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• v.6 no.3
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• pp.321-325
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• 1991

In thisstudy, effects of medium components on microbial production of L-phenylalanine by Corynebacterium glutamicum were investigated. The effect of carbon source on the production of L-phenylalanine was significant. Molasses enhanced the production of L-phenylalanine compared to sucrose, glucose, fructose, or their mixture. It was noticed that trace salts were required for the cell growth and product formation in the minimal medium, but excess amounts of trace salts had no effect on the production of L-phenylalanine. It was also found that optimum amounts of biotin and thiamine were required for the cell growth and the production of L -phenylalanine.

• Korean Journal of Microbiology
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• v.23 no.4
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• pp.265-270
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• 1985

Overall procedure of cell fusion between Brevibacterium flavum and Corynebacterium glutamicum was morphologically observed by transmission electron microscopy. Protoplasts formed by treatment of cells with penicillin G and lysozyme in order were released through the pores generated on a certain region of cell walls to be spherical form. When two different protoplasts were met, cell wall and membrane in the contact zone was disappeared and followed by the mutual exchange of cytoplasmic and/or chromosomal materials. Cell xall regeneration speed of the protoplasts fused was slower than that of the non-fused, whereas the size of the former was confirmed as bigger than that of the latter.

• Journal of Microbiology and Biotechnology
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• v.31 no.11
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• pp.1465-1480
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• 2021

Violacein, a purple pigment first isolated from a gram-negative coccobacillus Chromobacterium violaceum, has gained extensive research interest in recent years due to its huge potential in the pharmaceutic area and industry. In this review, we summarize the latest research advances concerning this pigment, which include (1) fundamental studies of its biosynthetic pathway, (2) production of violacein by native producers, apart from C. violaceum, (3) metabolic engineering for improved production in heterologous hosts such as Escherichia coli, Citrobacter freundii, Corynebacterium glutamicum, and Yarrowia lipolytica, (4) biological/pharmaceutical and industrial properties, (5) and applications in synthetic biology. Due to the intrinsic properties of violacein and the intermediates during its biosynthesis, the prospective research has huge potential to move this pigment into real clinical and industrial applications.

• Journal of Life Science
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• v.28 no.6
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• pp.656-662
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• 2018

Flavin-containing monooxygenases from Corynebacterium (cFMOs) were mutagenized based on homology modeling to develop variants with an enhanced indigoid production capability. The four mutants, F170Y, A210G, A210S, and T326S, which fused to a maltose-binding protein (MBP), were constructed, and their biochemical properties were characterized. Of these, purified MBP-T326S required a higher concentration of exogenous FAD (100 mM) than the wild-type MBP-cFMO for optimal activity and showed a 3.8-fold increase in the $k_{cat}/K_m$ value at $100{\mu}M$ FAD compared to that of MBP-cFMO at $2{\mu}M$ FAD. The indole oxygenase activities of MBP-T326S decreased to 63-77% compared to that of the MBP-cFMO In addition, MBP-T326S displayed a very low level of futile NADPH oxidase activities (21-24%) in the absence of a substrate. Mutant proteins except for T326S displayed similar $K_m$ and increased $k_{cat}/K_m$ values compared to the wild-type. MBP-F170Y and -A210S mutants showed elevated indole oxygenase activity higher than 3.1- and 2.9-fold, respectively, in comparison with MBP-cFMO. When indigoid production was carried out in LB broth with 2.5 g/l of tryptophan, Escherichia coli expressing cFMO produced 684 mg/l of indigo and 104 mg/l of indirubin, while cells harboring T326S produced 1,040 mg/l of indigo and 112 mg/l of indirubin. The results indicate that the production of indigo was 13% higher when compared to a previous report in which an E. coli expressing FMO from Methylophaga produced 920 mg/l of indigo. The protein engineering of cFMO based on homology modeling provided a more rational strategy for developing indigoid-producing strains.

• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.154-163
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• 1989

This studies were designed to improve the productivity of L-lysine by protoplast fusion and immobilized system of fusants using strains of Brevibacterium flavum ATCC 21528, Brevibacterium lactofermentum ATCC 21086 and Corynebacterium glutamicum 820. Mutants were isolated with concentration method of $300{\mu}g/ml$ penicillin-G after treatment of $250{\mu}g/ml$ N-methyl-N-nitro-N-nitrosoguanidine. B. flavum $37-2(Hos^-,\;Kan^r,\;AEC^r)$, B. lactofermentum $6-2(Ile^-,\;Val^-,\;Str^r,\;AEC^r)$ and C. glutamicum 57-5$(Met^-,\;Thr^-,\;Rif^r,\;AEC^r)$ were isolated from mutants. Protoplasts were induced by being incubated with $500{\mu}g/ml$ lysozyme of lysis solution for 6 hr and the ratio of protoplast formation and regeneration were ranging from 97-99% and 33-37%, respectively. Fusion frequencies of fusants of BBFL 21, BCFG 37 and BCLG 59 were shown in the range from $1.25{\times}10^{-6}\;to\;5.83{\times}10^{-7}$ under the optimum conditions. The fusant BBFL 21 showed the highest productivity of $411.1\;ng/ml{\cdot}hr$ L-lysine in the lysine productivity broth at $30^{\circ}C$ for 72hr. In the immobilization systems, fusant BBFL 21 was employed in various polymer matrices such as sodium alginate, polyacrylamide, agar and ${\alpha}-carrageena$. The immobilization of sodium alginate showed the highest productivity of $413\;ng/ml{\cdot}hr$ L-lysine in the batch system. Continuous fermentation of immobilization system by using tube fermentor was produced the highest productivity $416.7\;ng/ml{\cdot}hr $ L-lysine under optimum condition.

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.741-748
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• 2019

As the occurrence of harmful algal blooms (HABs) have become severe in precious water resources, the development of efficient harmful algae treatment methods is considering as an important environmental issue for sustainable conservation of water resources. To treat HABs in water resources, various conventional physical and chemical methods have been utilized and showed treatment efficiency, However, these methods can lead to discharging of cyanotoxins into the water bodies by chemical or physical algal cell lysis or destruction. Thus, to overcome this limitation, the development of safe HABs treatment methods is required. In the present study, adsorption technology was investigated for the removal of harmful algal species, Microcystis aeruginosa from aqueous phases. Industrial waste biomass, Corynebacterium glutamicum biomass was valorized as biosorbent (PEI-modified alginate/biomass composite fiber; PEI-AlgBF) for M. aeruginosa through immobilization with alginate matrix and cationic polymer (polyethylenimine; PEI) coating. The functional groups characteristic of PEI-Alg was determined using FT-IR analysis. By adsorption process used PEI-AlgBF, 52 and 67% of M. aeruginosa could be removed under the initial density of M. aeruginosa 200×10⁴ cells mL^-1 and 50×10⁴ cells mL^-1, respectively. As the increasing surface area of PEI-AlgBF, the removal efficiency was increased. In addition, we could find that adsorptive removal of M. aeruginosa has occurred without any M. aeruginosa cell lysis and destruction.