• 제목/요약/키워드: environmental biotechnology

검색결과 4,113건 처리시간 0.037초

Anammox Bacteria Enrichment in Upflow Anaerobic Sludge Blanket (UASB) Reactor

  • Thuan Tran-Hung;Jahng Deok-Jin;Jung Jin-Young;Kim Dong-Jin;Kim Won-Kyoung;Park Young-Joo;Kim Ji-Eun;Ahn Dae-Hee
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제9권5호
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    • pp.345-351
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    • 2004
  • We investigated the anaerobic ammonium oxidation (anammox) reaction in a lab-stale upflow anaerobic sludge blanket (UASB) reactor. Our aim was to detect and enrich the organisms responsible for the anammox reaction using a synthetic medium that contained low concentrations of substrates (ammonium and nitrite). The reactor was inoculated with granular sludge collected from a full-scale anaerobic digestor used for treating brewery wastewater The experiment was performed during 260 days under conditions of constant ammonium concentration ($50\;mg\;NH_4^+-N/L$) and different nitrite concentrations ($50{\~}150\;mg\;NO_2-N/L$). After 200 days, anammox activity was observed in the system. The microorganisms involved in this anammox reaction were identified as Candidatus B. Anammoxidans and K. Stuttgartiensis using fluorescence in situ hybridization (FISH ) method.

Molecular and Functional Characterization of Monocot-specific Pex5p Splicing Variants, Using OsPex5pL and OsPex5pS from Rice (Oryza sativa)

  • Lee, Jung Ro;Jung, Ji Hyun;Kang, Jae Sook;Kim, Jong Cheol;Jung, In Jung;Seok, Min Sook;Kim, Ji Hye;Kim, Woe Yeon;Kim, Min Gab;Kim, Jae-Yean;Lim, Chae Oh;Lee, Kyun Oh;Lee, Sang Yeol
    • Molecules and Cells
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    • 제23권2호
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    • pp.161-169
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    • 2007
  • We identified two alternatively spliced variants of the peroxisomal targeting signal 1 (PTS1) receptor protein Pex5ps in monocot (rice, wheat, and barley) but not in dicot (Arabidopsis and tobacco) plants. We characterized the molecular and functional differences between the rice (Oryza sativa) Pex5 splicing variants OsPex5pL and OsPex5pS. There is only a single-copy of OsPEX5 in the rice genome and RT-PCR analysis points to alternative splicing of the transcripts. Putative light-responsive cis-elements were identified in the 5' region flanking OsPEX5L and Northern blot analysis demonstrated that this region affected light-dependent expression of OsPEX5 transcription. Using the pex5-deficient yeast mutant Scpex5, we showed that OsPex5pL and OsPex5pS are able to restore translocation of a model PTS1 protein (GFP-SKL) into peroxisomes. OsPex5pL and OsPex5pS formed homo-complexes via specific interaction domains, and interacted with each other and OsPex14p to form hetero-complexes. Although overexpression of OsPex5pL in the Arabidopsis pex5 mutant (Atpex5) rescued the mutant phenotype, overexpression of OsPex5pS only resulted in partial recovery.

Higher Biomass Productivity of Microalgae in an Attached Growth System, Using Wastewater

  • Lee, Seung-Hoon;Oh, Hee-Mock;Jo, Beom-Ho;Lee, Sang-A;Shin, Sang-Yoon;Kim, Hee-Sik;Lee, Sang-Hyup;Ahn, Chi-Yong
    • Journal of Microbiology and Biotechnology
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    • 제24권11호
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    • pp.1566-1573
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    • 2014
  • Although most algae cultivation systems are operated in suspended culture, an attached growth system can offer several advantages over suspended systems. Algal cultivation becomes light-limited as the microalgal concentration increases in the suspended system; on the other hand, sunlight penetrates deeper and stronger in attached systems owing to the more transparent water. Such higher availability of sunlight makes it possible to operate a raceway pond deeper than usual, resulting in a higher areal productivity. The attached system achieved 2.8-times higher biomass productivity and total lipid productivity of $9.1g\;m^{-2}day^{-1}$ and $1.9g\;m^{-2}day^{-1}$, respectively, than the suspended system. Biomass productivity can be further increased by optimization of the culture conditions. Moreover, algal biomass harvesting and dewatering were made simpler and cheaper in attached systems, because mesh-type substrates with attached microalgae were easily removed from the culture and the remaining treated wastewater could be discharged directly. When the algal biomass was dewatered using natural sunlight, the palmitic acid (C16:0) content increased by 16% compared with the freeze-drying method. There was no great difference in other fatty acid composition. Therefore, the attached system for algal cultivation is a promising cultivation system for mass biodiesel production.

Isolation of CONSTANS as a TGA4/OBF4 Interacting Protein

  • Song, Young Hun;Song, Na Young;Shin, Su Young;Kim, Hye Jin;Yun, Dae-Jin;Lim, Chae Oh;Lee, Sang Yeol;Kang, Kyu Young;Hong, Jong Chan
    • Molecules and Cells
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    • 제25권4호
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    • pp.559-565
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    • 2008
  • Members of the TGA family of basic domain/leucine zipper transcription factors regulate defense genes through physical interaction with NON-EXPRESSOR OF PR1 (NPR1). Of the seven TGA family members, TGA4/octopine synthase (ocs)-element-binding factor 4 (OBF4) is the least understood. Here we present evidence for a novel function of OBF4 as a regulator of flowering. We identified CONSTANS (CO), a positive regulator of floral induction, as an OBF4-interacting protein, in a yeast two-hybrid library screen. OBF4 interacts with the B-box region of CO. The abundance of OBF4 mRNA cycles with a 24 h rhythm under both long-day (LD) and short-day (SD) conditions, with significantly higher levels during the night than during the day. Electrophoretic mobility shift assays revealed that OBF4 binds to the promoter of the FLOWERING LOCUS T (FT) gene, a direct target of CO. We also found that, like CO and FT, an OBF4:GUS construct was prominently expressed in the vascular tissues of leaf, indicating that OBF4 can regulate FT expression through the formation of a protein complex with CO. Taken together, our results suggest that OBF4 may act as a link between defense responses and flowering.

Fomitoside K, a New Lanostane Triterpene Glycoside from the Fruiting Body of $Fomitopsis$ $nigra$

  • Lee, In-Kyoung;Jung, Jin-Young;Yeom, Ji-Hee;Ki, Dae-Won;Lee, Myeong-Seok;Yeo, Woon-Hyung;Yun, Bong-Sik
    • Mycobiology
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    • 제40권1호
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    • pp.76-78
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    • 2012
  • In an effort to identify the chemical constituents of fruiting bodies of $Fomitopsis$ $nigra$, a new lanostane triterpene glycoside, designated as fomitoside K, has been isolated from its methanolic extract. Its chemical structure was assigned on the basis of various spectroscopic studies.