• Title/Summary/Keyword: n. sp.

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Enhancement of Denitrification Capacity of Pseudomonas sp. KY1 through the Optimization of C/N ratio of Liquid Molasses and Nitrate (액상 당밀과 질산성 질소의 C/N 비율에 따른 Pseudomonas sp. KY1의 탈질 능력 및 그 최적비율에 관한 연구)

  • Lee, Kyuyeon;Lee, Byung Sun;Shin, Doyun;Choi, Yongju;Nam, Kyoungphile
    • Journal of Korean Society of Environmental Engineers
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    • v.35 no.9
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    • pp.654-659
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    • 2013
  • This study was conducted to identify an optimal ratio of carbon to nitrogen (C/N ratio) for denitrification of nitrate using molasses as an external carbon source. A series of batch and column tests was conducted using an indigenous bacterium Pseudomonas sp. KY1 isolated from a nitrate-contaminated soil. For the initial nitrate-nitrogen concentration of 100 mg-N/L, batch test results indicated that C/N ratio of 3/1 was the optimal ratio with a relatively high pseudo-first-order reaction constant of $0.0263hr^{-1}$. At C/N ratio of 3/1, more than 80% of nitrate-nitrogen concentration of 100 mg-N/L was removed in 100 hrs. Results of column tests with a flow velocity of 0.3 mL/min also indicated that the C/N ratio of 3/1 was optimal for denitrification with minimizing remaining molasses concentrations. After 172 hrs of column operation (35 pore volumes) with an influent nitrate-nitrogen concentration of 100 mg-N/L, the effluent met the drinking water standard (i.e., 10 mg $NO_3$-N/L).

Purification and Characterization of Phenoxazinone Synthase from Streptomyces sp. V-8 Mutant Producing Adenoside Deaminase Inhibitor (아데노신 탈아미노화 효소 억제제를 생산하는 Streptomyces sp. V-8의 변이종으로부터 페녹사지논 합성효소의 분리 및 특성)

  • 김경자;조성진
    • YAKHAK HOEJI
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    • v.43 no.1
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    • pp.68-76
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    • 1999
  • Phenoxazinone synthase catalyzes the oxidative condensation of two molecules of substituted o-aminophenol to the phenoxazinone chromophore of actinomycin. Mutant strain, Streptomyces sp. V-8-M-1 producing higher phenoxazinone synthase, was obtained from Streptomyces sp. V-8 by treatment of N-methyl-N'-nitro-N-nitrosoguanidine. The phenoxazinone synthase was purified from extract of mutant strain of Streptomyces sp. V-8-M-l by successive steps of streptomycin sulfate, ammonium sulfate precipitation. DEAE-cellulose and Sephadex G-200 column chromatography. Molecular weight of the enzyme was 360,000 daltons. The enzyme was composed of octamer of a single subunit of 45,000 daltons. The Km value and Vmax value for 3-HAA were $14.9{\;}{\mu}M$ and 9.5 mg/U, respectively. The optimal pH and temperature for the enzyme activity were 9.0 and $25~30^{\circ}C$, respectively. Treatment of the enzyme with group specific reagents, phenylglyoxal, p-hydroxymercury-benzoate, Nbromosuccinimide, 5.5'-dithiobis-nitrobenzoic acid and ethylmaleimide resulted in loss of enzyme activity, which shows arginine and cysteine residues are at or near the active site.

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Purification and Characterization of Alkali-resistant Amylases from Pseudomonas sp. (Pseudomonas sp.로부터 알칼리내성 amylase의 정제 및 특성 확인)

  • Lee, Jeong-Eun;Jhon, Deok-Young
    • Korean Journal of Food Science and Technology
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    • v.40 no.1
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    • pp.70-75
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    • 2008
  • Two extracellular amylase isozymes were purified and characterized from alkalophilic Pseudomonas sp. KFCC 10818 for the production of maltooligosaccharides. The molecular weights of the homogeneous proteins were 50 kDa and 75 kDa, respectively. The 50 and 75 kDa amylases showed optimum temperatures at 35 and $40^{\circ}C$, respectively. The optimum pH of the enzymes ranged from pH 6-8, and the enzymes were resistant to an alkaline condition of pH 12. Via the enzyme's actions, the final products from maltooligosaccharides or soluble starch were maltose and maltotriose. Calcium was a potent activator of the 50 kDa amylase. Finally, the N-terminal amino acid sequences of the 50 and 75 kDa amylases were QTVPKTTFV and DTVPGNAFQ, respectively.

Optimal Culture Conditions for Production of Environment-Friendly Biosurfactant by Pseudomonas sp. EL-G527 (Pseudomonas sp. EL-G527에 의한 환경친화성 생물계면활성제의 생산최적조건)

  • 차미선;임은경;이근희;조순자;손홍주;이상준
    • Journal of Environmental Science International
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    • v.11 no.3
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    • pp.177-182
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    • 2002
  • A biosurfactant-producing microorganism was isolated from activated sludge by enrichment culture when grown on a minimal salt medium containing n-hexadecane as a sole carbon source. This microorganism was identified as Pseudomonas sp. and it was named Pseudomonas sp. EL-G527. It's optimal culture condition is 2% n-hexadecane, 0.2% NH$_4$NO$_3$, 0.3% KH$_2$PO$_4$, 0.3% $K_2$HPO$_4$, 0.02% MgSO$_4$ㆍ7$H_2O$, 0.0025% CaCk$_2$ㆍ6$H_2O$, 0.0015% FeSO$_4$ㆍ7$H_2O$ in 1$\ell$ distilled water and initial pH 7.0. Cultivation was initiated with a 2% inoculum obtained from starter cultures grown in 30 $m\ell$ of the same medium in 250 $m\ell$ flask. They were cultivated at 3$0^{\circ}C$ in reciprocal shaking incubator and the highest biosurfactant production was observed after 4 days.

Cellular Lipid Formation by Petroleum Hydrocarbon Fermentation (石油炭化水素 醱酵에 의한 脂質의 生成)

  • Park Tai Won;Suh Hyung Joon
    • Journal of the Korean Chemical Society
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    • v.21 no.6
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    • pp.449-452
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    • 1977
  • The effect of carbon number of hydrocarbon used as a carbon source in the production of cellular lipid of Rhodotorula sp. and its fatty acid composition were investigated. Using Rhodotorula sp. on n-tetradecane and n-hexadecane whose carbon numbers are even, fermentation was carried out in a jar fermentor of 2 liter-capacity at $28^{\circ}C$, with pH range of 4.0∼4.6 and at oxygen flowing rate of 0. 4 vvm and agitation velocity of 1000 rpm. Drying the produced cell after completion of fermentation, cellular lipid was extracted from the cell using soxhlet extractor and examined its fatty acid composition by gas-liquid chromatography. Cellular lipid content in the cell produced on n-tetradecane and n-hexadecane were 12.0 % and 25,8 % on the basis of dry cell weight, respectively and their fatty acids were mostly even numbered in carbon number.

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Purification and Characterization of Biosurfactant from Tsukamurella sp. 26A

  • Choi, Kyung-Suk;Kim, Soon-Han;Lee, Tae-Ho
    • Journal of Microbiology and Biotechnology
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    • v.9 no.1
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    • pp.32-38
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    • 1999
  • A biosurfactant produced by Tsukamurella sp. 26A was purified by procedures including acid precipitation, ethylacetate extraction, and adsorption chromatography. The purified biosurfactant reduced the surface tension of water from 72 mN/m to 30 mN/m at a concentration of 250 mg/l, whereas the minimum interfacial tension against n-hexadecane was lowered to 1.5 mN/m at a concentration of 40 mg/i. The compound stabilized oil-in-water emulsions with a variety of commercial oils and had strong emulsification and stabilization activities when compared to those of commercial emulsifiers and stabilizers. Surface tension was stable over a broad range of pH (2-12) and temperature ($100^{\circ}C$, 3h). The biosurfactant was identified as glycolipid having a hydrophilic moiety of trehalose.

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Giardella ricoensis n. sp. from the West Indies and the Proposal of the New Genus Goodingius (Copepoda: Cyclopoida: Clausidiidae)

  • Kim, Il-Hoi
    • Animal Systematics, Evolution and Diversity
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    • v.23 no.2
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    • pp.127-133
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    • 2007
  • A new genus Goodingius is proposed to incorporate Hemicyclops adhaerens(Williams), H. arenicolae Gooding, H. elongatus Wilson and H. subadhaerens Gooding, all of which bear the six-segmented female urosome, three mandibular elements (or three elements plus one rudimentary setule), five setae on the first antennular segment, and no inner coxal seta of leg 4. The genus Giardella Canu, a sister taxon of Goodingius, is redefined as possessing eight elements on the third exopodal segment of leg 3, only a single inner seta on the second endopodal segment of leg 4, four spines on the third endopodal segment of leg 4. To the genus Giardella, Hemicyclops caissarum Kihara and Rocha and H. carinifer Humes are assigned, in addition to Giardella ricoensis n. sp., Giardella callianassae Canu, and G. thompsoni A. Scott. Keys to the species of both genera are provided.