• Title/Summary/Keyword: resting cell

Search Result 33, Processing Time 0.14 seconds

토착미 생물을 이용한 TNT(2,4,6-Trinitrotoluene)의 생물학적분해

  • 배범한;유경민;장윤영;이인숙
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
    • /
    • /
    • pp.235-238
    • /
    • 2002
  • Microorganisms were isolated from military shooting site. Aerobic batch reactor and resting cell condition experiments were carried out using isolated microorganisms. Experiments were examined at room temperature on shaker and ten-roll mixer. During 10 days of reaction time, TNT was degraded 15.51 ~ 22.47 mg/L from initial concentration(31$\pm$1 mg/L) by aerobic batch reactor. Aerobic resting cell condition experiments were carried out ill phosphate buffer with 58($\pm$1) mg/L TNT at pH of 6.0($\pm$0.2). TNT was degraded 67.8% of initial concentration. The mai or component was found 4-ADNT(4-Aminodinitrotoluene).

  • PDF

Studies on the Production of Gluconic Acid by Resting Cell System of Aspergillus niger (Aspergillus niger의 휴지균체에 의한 Gluconic Acid생성에 관한 연구)

  • 정지관;양호석;신규철;양한철
    • Microbiology and Biotechnology Letters
    • /
    • v.9 no.1
    • /
    • pp.7-19
    • /
    • 1981
  • The production of gluconic acid from glucose by the resting cell system of Aspergillus niger was studied. It was found that the conversion products from glucose by the resting cell system were markedly influenced by the pH, temperature, substrate concentration, aeration, metal ions, cultivation time and storage conditions of the resting cells. Conversion products were identified as gluconic acid by the thin layer chromatography and infrared spectrophotometry. These conversions were greatly stimulated by addition of $Mg^{++}$, and S $n^{++}$, but showed inhibitory effects by C $u^{++}$, H $g^{++}$, C $d^{++}$, A $g^{+}$ and cyanide. For the optimum cell storage, it was effective to be kept at -$25^{\circ}C$ in 0.05M phosphate buffer solution of pH 7.0. The gluconic acid production by the resting cell system was more effective than those of the fermentation with respect to cultivation time, yield, recovery and re-use of the cell.l.l.l.l.l.l.

  • PDF

Optimal Conditions and Substrate Specificity for Trehalose Production by Resting Cells of Arthrobacter crystallopoietes N-08

  • Seo, Yi-Seul;Shin, Kwang-Soon
    • Preventive Nutrition and Food Science
    • /
    • v.16 no.4
    • /
    • pp.357-363
    • /
    • 2011
  • Recently, we found that Arthrobacter crystallopoietes N-08 isolated from soil directly produces trehalose from maltose by a resting cell reaction. In this study, the optimal set of conditions and substrate specificity for the trehalose production using resting cells was investigated. Optimum temperature and pH of the resting cell reaction were $55^{\circ}C$ and pH 5.5, respectively, and the reaction was stable for two hours at $37{\sim}55^{\circ}C$ and for one hour at the wide pH ranges of 3~9. Various disaccharide substrates with different glycosidic linkages, such as maltose, isomaltose, cellobiose, nigerose, sophorose, and laminaribiose, were converted into trehalose-like spots in thin layer chromatography (TLC). These results indicated broad substrate specificity of this reaction and the possibility that cellobiose could be converted into other trehalose anomers such as ${\alpha},{\beta}$- and ${\beta},{\beta}$-trehalose. Therefore, the product after the resting cell reaction with cellobiose was purified by ${\beta}$-glucosidase treatment and Dowex-1 ($OH^-$) column chromatography and its structure was analyzed. Component sugar and methylation analyses indicated that this cellobiose-conversion product was composed of only non-reducing terminal glucopyranoside. MALDI-TOF and ESI-MS/MS analyses suggested that this oligosaccharide contained a non-reducing disaccharide unit with a 1,1-glucosidic linkage. When this disaccharide was analyzed by $^1H$-NMR and $^{13}C$-NMR, it gave the same signals with ${\alpha}$-D-glucopyranosyl-(1,1)-${\alpha}$-D-glucopyranoside. These results suggest that cellobiose can be converted to ${\alpha},{\alpha}$-trehalose by the resting cells of A. crystallopoietes N-08.

EFFECTS OF TRANSFORMATION CAPACITY ON COMETABOLIC DEGRADATION OF TRICHLOROETHENE

  • Lee, Seung-Bong;Kim, Geon-Ha
    • Environmental Engineering Research
    • /
    • v.10 no.2
    • /
    • pp.79-87
    • /
    • 2005
  • The effects of transformation capacity on cometabolic degradation of trichloroethene (TCE) were evaluated using TCE-degrading actinomycetes pure and mixed culture under various culture conditions. The TCE transformation capacity of the actinomycetes enrichment culture in a batch test with phenol addition was 1.0 mg of TCE/mg of volatile suspended solids (VSS). The resting cell TCE transformation capacity of the actinomycetes pure culture cell was 0.75 mg TCE/mg VSS, which increased to 2.0 mg TCE/mg VSS when phenol was added as an external substrate. When the pure culture had an internal substrate in the form of poly-β-hydroxybutyrate (PHB) at 19% of the cell mass, the resting cell TCE transformation capacity increased from 0.47 to 0.6 mg TCE/mg VSS. The presence of PHB increased transformation capacity by 57%, whereas, the addition of phenol caused more than two fold increase in transformation capacity. The actinomycetes culture showed the highest transformation capacity.

Isolation and Identification of Aldehyde Producing Methanol Utilizing Yeast (메탄올 자화성 효모의 분리, 동정 및 Aldehyde 생산)

  • 윤병대;김희식;권태종;양지원;권기석;이현선;안종석;민태익
    • Microbiology and Biotechnology Letters
    • /
    • v.20 no.6
    • /
    • pp.630-636
    • /
    • 1992
  • Hansenula nonfermentans KYP-l was selected and identified from 19 methanol utilizing yeasts isolated from soil samples by the enrichment culture technique. This strain showed a high cell concentration and a high aldehyde production. Aldehyde production was carried out in a resting cell system using methanol utilizing yeast as a biocatalyst. The molar yield of acetaldehyde was the highest among the aldehyde investigated, and the maximum amount of aldehyde was produced by cells obtained from a 40 hours' culture.

  • PDF

Improved NADPH Regeneration for Fungal Cytochrome P450 Monooxygenase by Co-Expressing Bacterial Glucose Dehydrogenase in Resting-Cell Biotransformation of Recombinant Yeast

  • Jeon, Hyunwoo;Durairaj, Pradeepraj;Lee, Dowoo;Ahsan, Md Murshidul;Yun, Hyungdon
    • Journal of Microbiology and Biotechnology
    • /
    • v.26 no.12
    • /
    • pp.2076-2086
    • /
    • 2016
  • Fungal cytochrome P450 (CYP) enzymes catalyze versatile monooxygenase reactions and play a major role in fungal adaptations owing to their essential roles in the production avoid metabolites critical for pathogenesis, detoxification of xenobiotics, and exploitation avoid substrates. Although fungal CYP-dependent biotransformation for the selective oxidation avoid organic compounds in yeast system is advantageous, it often suffers from a shortage avoid intracellular NADPH. In this study, we aimed to investigate the use of bacterial glucose dehydrogenase (GDH) for the intracellular electron regeneration of fungal CYP monooxygenase in a yeast reconstituted system. The benzoate hydroxylase FoCYP53A19 and its homologous redox partner FoCPR from Fusarium oxysporum were co-expressed with the BsGDH from Bacillus subtilis in Saccharomyces cerevisiae for heterologous expression and biotransformations. We attempted to optimize several bottlenecks concerning the efficiency of fungal CYP-mediated whole-cell-biotransformation to enhance the conversion. The catalytic performance of the intracellular NADPH regeneration system facilitated the hydroxylation of benzoic acid to 4-hydroxybenzoic acid with high conversion in the resting-cell reaction. The FoCYP53A19+FoCPR+BsGDH reconstituted system produced 0.47 mM 4-hydroxybenzoic acid (94% conversion) in the resting-cell biotransformations performed in 50 mM phosphate buffer (pH 6.0) containing 0.5 mM benzoic acid and 0.25% glucose for 24 h at $30^{\circ}C$. The "coupled-enzyme" system can certainly improve the overall performance of NADPH-dependent whole-cell biotransformations in a yeast system.

Production of a Biosurfactant Mannosylerythritol Lipid by Resting Cell of Candida sp. SY16. (Candida sp. SY16의 휴식세포를 이용한 생물계면활성제 Mannosylerythritol Lipid의 생산)

  • 김희식;전종운;최우영;오희목;이기형;권태종;윤병대
    • Microbiology and Biotechnology Letters
    • /
    • v.30 no.2
    • /
    • pp.167-171
    • /
    • 2002
  • The resting cells of Candida sp. SY16 produced a large amount of mannosylerythritol lipid as a biosurfactant when incubated in the distilled water containing only the carbon source. The resting cells exhibited the highest production at 20 g cells per liter on the soybean oil of 75 g/1 as a sole substrate and pH 4∼5 in the shaking culture. Under the optimal conditions, the biosurfactant was extracellularly produced to 58 g/1 after 120 h in jar fermentor, and the yield became higher than that obtained by using the glowing cells of the strain in batch fermentation.

Metabolism of Dimethylphthalate by Aspergillus niger

  • Pradeepkmar;Sharanagouda;Karegoudar, T.B.
    • Journal of Microbiology and Biotechnology
    • /
    • v.10 no.4
    • /
    • pp.518-521
    • /
    • 2000
  • Aspergillus niger is capable of metabolizing dimethyphthalate. The maximum weight of mycelium wa observed afterabout 6-8 dys of incubation. A TLC analysis revealed the accumulation of metabolites in the resting cell culture. Monomethylphthalate, phthalate, and protocatechuate were shown to be the intermediates by thin layer chromatographic and spectrophotometric analyses. The fungus metabolized dimethylphthalate through monomethylphthalate, phthalate, and protocatechuate as evidenced by the oxygen uptake and an enzymatic analysis. The terminal aromatic metabolite, protocatechuate, is metabolized via the ortho-cleavage pathway.

  • PDF

화석연료의 탈황을 위한 DBT 분해 미생물의 탐색

  • Im, Seong-Jun;Lee, Seon-Bok
    • 한국생물공학회:학술대회논문집
    • /
    • /
    • pp.549-552
    • /
    • 2000
  • A microorganism which can desulfurize dibenzothiophene (DBT) to 2-hydroxybiphenyl (2-HBP) was isolated from coal samples. The rate of DBT desulfurization was enhanced by the presence of yeast extract. In the case of DBT desulfurization by resting cells the rate and extent of 2-HBP production was enhanced with the addition of Tween 80.

  • PDF

Cloning and Expression of pcbAB Genes from Pseudomonas sp. DJ-12 in Escherichia coli (Pseudomonas sp. DJ-12 pcbAB 유전자의 Escherichia coli에서의 클로닝 및 발현)

  • 한재진;성태경;김치경
    • Korean Journal of Microbiology
    • /
    • v.31 no.2
    • /
    • pp.129-134
    • /
    • 1993
  • The pchAB genes of Pseudomonas sp. DJ-12 produce the enzymes of 4-chlorobipheny] (4CB) dioxygenase and dihydrodiol dehydrogenase which act on the first and second steps in degradation of 4CB and biphenyl. The genes were cloned in E coli XLI-Blue. The pcbAB genes of about 2.2 kb in size were contained in the pCUlO1 hybrid plasmid in the cloned cell of CUIOI. The genes were found to have their own promoter and three restriction sites for HindlII. 2,3-dihydroxybiphenyl was detected by the resting cell assay, as the metabolite transformed from biphenyl by the cloned cell of CUIOI. This means that the pcbAB genes are well expressed in E. coli. But dechlorination was unlikely involved in the pchAB gene expression but was believed to occur by functioning on 4CBA produced after ring-cleavage of 4CB.

  • PDF