• 제목/요약/키워드: biological reduction

검색결과 1,224건 처리시간 0.029초

'Cyclitol 유도체(誘導體) 합성(合成)에 관(關)한 연구(硏究)' -Inositol stereomer 와 p-Hydroxybenzoate의 합성(合成)과 식품공업상(食品工業上) 응용(應用)을 위한 항균시험(抗菌試驗)- ('Studies on the Synthesis of Cyclitol derivatives' -Synthesis of Inositols, p-Hydroxybenzoates and thier Antimicrobial test for food industry)

  • 손주환
    • Applied Biological Chemistry
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    • 제13권3호
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    • pp.197-205
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    • 1970
  • 1. myo-inositol (aeeeee) 에서 scyllo- (eeeeee), epi-(aeaeee) 및 muco-inositol (aaaeee)에 도달(到達)시킬 수 있었다. 2. inositol의 과산화수소(過酸化水素) 산화(酸化)는 ax. 수산기(水酸基)가 산화(酸化)되어 microbial oxidation, 접촉산화(接觸酸化)에서와 대등(對等)한 inosose를 얻고, 이것은 산성(酸性)에서 $NaBH_4$로 환원(還元)하면 eq.-alcohol이 되며, 한편 접촉산원(接觸還元)하면 az. alcohol 이 된다. 3. inositol의 p-HBA ester인 사종(四種) 신화합물(新化合物) [III], [XII], [XVI], [XXI]을 합성(合成)하였다. 4. 이들 ester는 모두 항균작용(抗菌作用)이 있고 pH의 저하(低下)로 증대(增大)되는 경향(領向)이 있으며 muco-inositol ester는 가장 강력(强力)하고, 이는 입체구조(立體構造)와 관련(關聯)되는 것 같다.

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구연산철 환원 조건하에서 Shewanella sp. HN-41에 의한 6가 크롬의 환원 (Reduction of Hexavalent Chromium by Shewanella sp. HN-41 in the Presence of Ferric-Citrate)

  • 박혜민;곽진협;이지훈
    • 한국환경농학회지
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    • 제42권3호
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    • pp.253-258
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    • 2023
  • In the environment, chromium often exists in a highly mobile and toxic form of Cr(VI). Therefore, the reduction of Cr(VI) to less toxic Cr(III) is considered an effective remediation strategy for Cr(VI)-contamination. In this study, the biological reduction of hexavalent chromium was examined at the concentrations of 0.01 mM, 0.1 mM, and 1 mM Cr(VI) by the dissimilatory metal-reducing bacterium, Shewanella sp. HN-41 in the presence of ferric-citrate. With the relatively condensed cell densities, the aqueous phase Cr(VI) was reduced at the proportions of 42%, 23%, and 31%, respectively for the 0.01 mM, 0.1 mM, and 1 mM Cr(VI) incubations, while Fe(III)-citrate was reduced at 95%, 88%, and 73%, respectively. Although the strain HN-41 was not considered to reduce Cr(VI) as the sole electron acceptor for anaerobic metabolism in the preliminary experiment, it has been presumed that outer-membrane c-type cytochromes such as MtrC and OmcA reduced Cr(VI) in the presence of ferric-citrate as the electron acceptor. Since this study indicated the potential of relatively high cell density for Cr(VI) reduction, it might propose a bioremediation strategy for Cr(VI) removal from contaminated waters using engineered systems such as bioreactors employing high cell growths.

Biological Control of Fusarium Wilt Disease of Pigeonpea

  • Rajesh Singh;B.K. Singh;R.S. Upadhyay;Bharat Rai;Lee, Youn-Su
    • The Plant Pathology Journal
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    • 제18권5호
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    • pp.279-283
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    • 2002
  • Biological control of Fusarium udum causing wilt disease of pigeonpea was studied in vitro, as well as, in vivo. Aspergilluspavus, Anergillus niger, Bacilius licheniformis (strain-2042), Gliocladium virens, Peniciliium citrimum, and Trichoderma harzianum, which were found to be the most potent ones in inhibiting the radial colony growth of the test pathogen, were used as biological control by amending their inocula at diffeyent concentrations in pots and in pathogen-infested soil in the fields. Maximum reduction of the wilt disease was observed with G. vireos both in pots and in the fields. The population of E. udum was found to be markedly reduced when the antagonists were applied in the soil. The study establishes that G. virens can be exploited for the biological control of wilt disease at field level.

Determining Optimum Condition of Acid Hydrolysis Technique for Food Waste Reduction

  • Kim, Eui Yeong;Choi, Young Gwang;Kim, Sung Chul
    • 한국토양비료학회지
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    • 제50권6호
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    • pp.606-614
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    • 2017
  • Amount of food waste has been increased annually in Korea and re-use of food waste as a fertilizer or soil amendment in agricultural field has been studied. Therefore, main purpose of this research was to determine optimum condition of hydrolysis for food waste management. Three different solvents, HCl, $H_2SO_4$, and KOH, were used and varied concentration at the range of 10~30% and hydrolysis time at the range of 1~3 hours were evaluated. In general, reduction rate of food waste was increased when concentration of solvent and hydrolysis time was increased except when KOH was used. Among different solvents, concentration, and hydrolysis time, the highest reduction rate (97.79%) was observed when 30% of HCl was used with temperature of $140^{\circ}C$ at 2 hours of hydrolysis time. In addition, neutralization effect of alkalic materials, shell waste (SW) and egg shell (ES) was evaluated. Both SW and ES increased pH of finished acid hydrolysis solution up to 7.61 indicating that neutralization effect of SW and ES was sufficient for finished acid hydrolysis solution. Contents of organic matter was also at the range of 10.7~13.04% and 5.53~8.04% respectively when HCl and $H_2SO_4$ were used as solvent. Overall, hydrolysis technique can be used to manage food waste with selected optimum condition in this study and characteristics of finished hydrolysis solution after neutralization might be suitable for soil amendments.

Biological nitrogen removal of ammonium-rich industrial wastewater by suspended bacterial growth

  • 임준택;성세현;황석환
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2002년도 생물공학의 동향 (X)
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    • pp.399-402
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    • 2002
  • Industrial wastewater with high ammonium concentration was treated in batch biological systems which was a modified Ludzack- Ettinger process. Up to 78% conversion of $NH_4\;^+-N$ to $NO_x\;^--N$ was achieved in batch culture condition. Under anoxic condition with methanol as the carbon source, the denitrifiers decreased $NO_x\;^--N$ concentration from 608 mg/L to 5.6 mg/L in 22 d. As well as anoxic denitrification of $NO_x\;^-$ to $N_2$, dissimilatory nitrate reduction to ammonium also occurred under the condition as respiratory denitrification.

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Optimization fluidization characteristics conditions of nickel oxide for hydrogen reduction by fluidized bed reactor

  • Lee, Jae-Rang;Hasolli, Naim;Jeon, Seong-Min;Lee, Kang-San;Kim, Kwang-Deuk;Kim, Yong-Ha;Lee, Kwan-Young;Park, Young-Ok
    • Korean Journal of Chemical Engineering
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    • 제35권11호
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    • pp.2321-2326
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    • 2018
  • We evaluated the optimal conditions for fluidization of nickel oxide (NiO) and its reduction into high-purity Ni during hydrogen reduction in a laboratory-scale fluidized bed reactor. A comparative study was performed through structural shape analysis using scanning electron microscopy (SEM); variance in pressure drop, minimum fluidization velocity, terminal velocity, reduction rate, and mass loss were assessed at temperatures ranging from 400 to $600^{\circ}C$ and at 20, 40, and 60 min in reaction time. We estimated the sample weight with most active fluidization to be 200 g based on the bed diameter of the fluidized bed reactor and height of the stocked material. The optimal conditions for NiO hydrogen reduction were found to be height of sample H to the internal fluidized bed reactor diameter D was H/D=1, reaction temperature of $550^{\circ}C$, reaction time of 60 min, superficial gas velocity of 0.011 m/s, and pressure drop of 77 Pa during fluidization. We determined the best operating conditions for the NiO hydrogen reduction process based on these findings.

풋마름병균, Ralstonia solanacearum의 길항세균 SKU-78 균주의 분리 동정 및 특성 (Isolation, Identification and Biological Control Activity of SKU-78 Strain against Ralstonia solanacearum)

  • 성필제;신정균;조홍범;김신덕
    • Applied Biological Chemistry
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    • 제48권1호
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    • pp.48-52
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    • 2005
  • 종자발아실험과 뿌리에서의 집락 형성실험으로 고추와 토마토의 근권 토양에서 plant growth promoting rhizobacteria(PGPR) 균주를 선발하였다. 그 중 포트실험에서 종자처리와 토양 관주처리 하였을 때 60% 이상 풋마름병 방제효과를 나타낸 SKU-78 균주에 대해서 포장에서의 방제효과 검증에 의해 생물농약으로의 개발 가능성을 확인하였으며, 생화학적 특성조사와 16S rDNA sequence 분석에 의해 SKU-78 균주를 Bacillus sp. SKU-78로 동정하였다.

Expression profile identifies novel genes involved in neuronal differentiation

  • Kim, Jung-Hee;Lee, Tae-Young;Yoo, Kyung-Hyun;Lee, Hyo-Soo;Cho, Sun-A;Park, Jong-Hoon
    • BMB Reports
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    • 제41권2호
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    • pp.146-152
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    • 2008
  • In the presence of NGF, PC12 cells extend neuronal processes, cease cell division, become electrically excitable, and undergo several biochemical changes that are detectable in developing sympathetic neurons. We investigated the expression pattern of the apoptosis-related genes at each stage of neuronal differentiation using a cDNA microarray containing 320 apoptosis-related rat genes. By comparing the expression patterns through time-series analysis, we identified candidate genes that appear to regulate neuronal differentiation. Among the candidate genes, HO2 was selected by real-time PCR and Western blot analysis. To identify the roles of selected genes in the stages of neuronal differentiation, transfection of HO2 siRNA in PC12 cells was performed. Down-regulation of HO2 expression causes a reduction in neuronal differentiation in PC12 cells. Our results suggest that the HO2 gene could be related to the regulation of neuronal differentiation levels.

Nucleotide Triphosphates Inhibit the Degradation of Unfolded Proteins by HslV Peptidase

  • Lee, Jung Wook;Park, Eunyong;Bang, Oksun;Eom, Soo-Hyun;Cheong, Gang-Won;Chung, Chin Ha;Seol, Jae Hong
    • Molecules and Cells
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    • 제23권2호
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    • pp.252-257
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    • 2007
  • Escherichia coli HslVU is an ATP-dependent protease consisting of two heat shock proteins, the HslU ATPase and HslV peptidase. In the reconstituted enzyme, HslU stimulates the proteolytic activity of HslV by one to two orders of magnitude, while HslV increases the rate of ATP hydrolysis by HslU several-fold. Here we show that HslV alone can efficiently degrade certain unfolded proteins, such as unfolded lactalbumin and lysozyme prepared by complete reduction of disulfide bonds, but not their native forms. Furthermore, HslV alone cleaved a lactalbumin fragment sandwiched by two thioredoxin molecules, indicating that it can hydrolyze the internal peptide bonds of lactalbumin. Surprisingly, ATP inhibited the degradation of unfolded proteins by HslV. This inhibitory effect of ATP was markedly diminished by substitution of the Arg86 residue located in the apical pore of HslV with Gly, suggesting that interaction of ATP with the Arg residue blocks access of unfolded proteins to the proteolytic chamber of HslV. These results suggest that uncomplexed HslV is inactive under normal conditions, but may can degrade unfolded proteins when the ATP level is low, as it is during carbon starvation.

염색폐수의 생물학적 전처리 조건변화에 의한 최적 펜톤시약 투입량 결정에 관한 연구 (Optimum Dosage of Fenton's Reagent for the Dyeing Wastewater by the Different Conditions of Biological Treatment as the Pre-treatment Process)

  • 배준삼;이상호
    • 한국환경과학회지
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    • 제14권7호
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    • pp.683-689
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    • 2005
  • The consecutive combination process of a biological process as the pre-treatment and a chemical process as the post-treatment is applied for the dyeing wastewater. The poor efficiency of biological treatment using pure oxygen makes the chemical treatment cost high. It is necessary to improve the efficiency of biological treatment in order to reduce the cost of chemical treatment. The purpose of this paper is to find the minimum dose of chemical reagent to fit the Discharged Water Quality Standards for the different biological treatment effluents. Results revealed that the minimum dosage of Fenton's reagent lead to save the cost of chemical treatment based on the guideline dose in the treatment plant. The possible maximum saving reagents was up to $70\%$ for the effluent of the pilot plant packed with the carrier imbedded microorganisms which were selected from the present treatment plant.