• Title/Summary/Keyword: Corynebacterium glutamicum

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Studies on Intergeneric Protoplast fusion and L-Lysine Productivity

  • 이인선;조정일
    • Journal of the East Asian Society of Dietary Life
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    • v.5 no.1
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    • pp.93-99
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    • 1995
  • For the improvement of the L-lysine productivity of Brevibacterium flavum and Corynebacterium glutamicum, fusants were induced by interspecific protoplast fusion of Bacillus subtilis with C. glutamicum and B. flavum. The following results were obtained through protoplast formation of strains condition of protoplast fusion, characteristics of the fusants, and the productivity of lysine form starch. B. flavum BF-5 and C. glutamicum protoplasts were made by the treatment of 0.3unit/$m\ell$ of penicillin G at the early stationary growth phase for 2 hours followed by incubation with 10mg/$m\ell$ of lysozyme at 37$^{\circ}C$ for 120 min. When a mixture of the protoplast was treated with 30% PEG(M.W.6,000) solution containing 50mM CaCl2 at optimal conditions, the intergeneric fusion frequency between protoplasts of C. glutamicum CG-2 and B. subtilis BD 224 was 7.1${\times}$105. The genetic properties on the L-lysine producing fusants were compared with those of parental strains. As a results, the intergeneric fusants were completed in each auxotrophic requirement, resistances for S-(2-amino-ethyl)-L-cysteine and kanamycine were confirmed. And one of fusants selected, FBB-41 were found to be genetically stable fusants. The aspartokinase activity of FBB-41 strain increased than that of the parent strain.

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Towards Methionine Overproduction in Corynebacterium glutamicum - Methanethiol and Dimethyldisulfide as Reduced Sulfur Sources

  • Bolten, Christoph J.;Schroder, Hartwig;Dickschat, Jeroen;Wittmann, Christoph
    • Journal of Microbiology and Biotechnology
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    • v.20 no.8
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    • pp.1196-1203
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    • 2010
  • In the present work, methanethiol and dimethyldisulfide were investigated as sulfur sources for methionine synthesis in Corynebacterium glutamicum. In silico pathway analysis predicted a high methionine yield for these reduced compounds, provided that they could be utilized. Wild-type cells were able to grow on both methanethiol and dimethyldisulfide as sole sulfur sources. Isotope labeling studies with mutant strains, exhibiting targeted modification of methionine biosynthesis, gave detailed insight into the underlying pathways involved in the assimilation of methanethiol and dimethyldisulfide. Both sulfur compounds are incorporated as an entire molecule, adding the terminal S-$CH_3$ group to O-acetylhomoserine. In this reaction, methionine is directly formed. MetY (O-acetylhomoserine sulfhydrylase) was identified as the enzyme catalyzing the reaction. The deletion of metY resulted in methionine auxotrophic strains grown on methanethiol or dimethyldisulfide as sole sulfur sources. Plasmid-based overexpression of metY in the ${\Delta}$metY background restored the capacity to grow on methanethiol or dimethyldisulfide as sole sulfur sources. In vitro studies with the C. glutamicum wild type revealed a relatively low activity of MetY for methanethiol (63 mU/mg) and dimethyldisulfide (61 mU/mg). Overexpression of metY increased the in vitro activity to 1,780 mU/mg and was beneficial for methionine production, since the intracellular methionine pool was increased 2-fold in the engineered strain. This positive effect was limited by a depletion of the metY substrate O-acetylhomoserine, suggesting a need for further metabolic engineering targets towards competitive production strains.

The Effect of Body Wash Containing Triclosan and Bamboo Salt on Axillary Malodor (Triclosan과 죽염을 함유한 바디워시의 액취 등에 미치는 효과에 대한 연구)

  • Roh, Seok-Sun;Yun, Woo-Sik;Jung, Ji-Young;Yu, Hyung-Uk;Hwang, Dong-Sung;Choi, Seung-Man;Lee, Jeong-Rae;Kang, Sang-Jin;Chang, Sug-Youn
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.35 no.3
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    • pp.219-228
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    • 2009
  • This study was performed to evaluate a deodorant body wash with 1.0 wt% of triclosan and 0.4 wt% of bamboo salt, which have an inhibitory effect on axillary malodor. In this studies, in vitro antibacterial study and the clinical study, which was designed by randomized assignment, double-blind and cross-over, were performed. In the antibacterial study, test sample, which was body wash having 1.0 wt% of triclosan and 0.4 wt% of bamboo salt, have a potent antibacterial effect on Corynebacterium glutamicum, Corynebacterium xerosis, Corynebacterium jeikeium. In the clinical study, test sample has a potent and significant deodorizing effect on axillary malodor and an antibacterial efficacy. And its efficacy was maintained for 9 h at least. There was no side effect during the period of clinical study. Consequently, body wash, containing 1.0 wt% of triclosan and 0.4 wt% of bamboo salt, has the effectiveness and the safety about axillary malodor reduction.

The protoplast formation, regeneration and fusion of coryneform bacteria (Coryneform bacteria의 原形質體 形成, 再生 및 融合에 관한 硏究)

  • Shin, Myung-Gyo;Lee, Se-Yong;Lim, Bun-Sam;Chun, Moon-Jin
    • Korean Journal of Microbiology
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    • v.22 no.3
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    • pp.175-181
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    • 1984
  • In order to develope a protoplast fusion system for industrial coryneform bacteria, the optimum conditions for the formation and regeneration of progoplast were examined for Brevibacterium flavum and Corynebacterium glutamicum and the protoplast fusion was performed. For the formation of the protoplast of B. flavum and C. glutamicum, the optimum time for penicillin G. treatment to obtain protoplast was mid-exponential growth phase ($O.D_{580}=0.6-0.8,\;8.0{\times}10^7-1.0{\times}10^8cell/ml$). At the optimum conditions (0.3units/ml penicillin G and $400{\mu}g/ml$ lysoyme for treatement), frequencies of protoplast formation and protoplast regeneration were 99% and 25%, respectively. Protoplast regeneration frequency was highest under the optimum conditions for the protoplast formation. Addition of 25mM $Mg^{2+}\;and\;50mM\;Ca^{2+}$ to the regeneration medium further increased the regeneration frequencies. The protoplast fusion frequencies of B. flavum and C. glutamicum in intraspecies fusion were $1.0{\times}10^{-8}\;and\;7.8{\times}10^{-4}$, of the regenerated protoplast respectively, when 33% of PEG (polythylene glycol) 6,000 was used as the fusing agent.

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