• Title/Summary/Keyword: Biological Processes

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Comparative Study on Biological Pretreatment Processes for Biologically Stable Drinking Water (생물처리를 이용한 상수원수의 전처리공정에 관한 비교연구)

  • 우달식;남상호
    • Journal of Environmental Health Sciences
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    • v.22 no.4
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    • pp.69-76
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    • 1996
  • Biological process have the potential to remove pollutants such as biodegradable organic fraction, $NH_3-N$, ABS, etc. that may be partially removed by conventional water treatment. This study was performed to evaluate four different processes of biological pretreatment as Biological Fluidized Bed(BFB), Biological Filter(BF), Rotating Biological Contactor(RBC) and Honey Comb(HC). In a given condition it proved out that BFB and BF are prospective biological pretreatment processes because they were the most effective on the removal of organic matter and ammonia. Preozonation of raw water for biological processes increased in biodegradable organic fraction about 10-40% with 0.425-0.85 mg $O_3/mg$ DOC.

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The Practical Application of Aqueous Two-Phase Processes for the Recovery of Biological Products

  • Rito-Palomares, Marco
    • Journal of Microbiology and Biotechnology
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    • v.12 no.4
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    • pp.535-543
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    • 2002
  • Although the generic implementation of aqueous two-phase systems (ATPS) processes for the recovery of biological products has been exploited for several years, this has not resulted in a wide adoption of the technique. The main reasons involve the poor understanding of the mechanism governing phase formation and the behavior of solute partitioning in ATPS processes, the cost of phase forming polymers, and the necessary extended time to optimize the technique. In this review paper, some of the practical disadvantages attributed to ATPS are addressed. The practical approach exploited to design ATPS processes, the application to achieve process integration, the extended use for the recovery of high-value products, and the recent development of new low-cost ATPS, are discussed. It is proposed that the trend of the practical application of ATPS processes for the recovery of biological products will involve the purification of new high-value bioparticulate products with medical applications. Such a trend will give new impetus to the technique, and will draw attention from industries needing to develop new, and improve existing, commercial processes.

Biological Hydrogen Production Processes (생물학적 수소생산 공정)

  • Shin, Jong-Hwan;Park, Tai Hyun
    • Korean Chemical Engineering Research
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    • v.44 no.1
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    • pp.16-22
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    • 2006
  • Biological hydrogen production processes are more environment-friendly and less energy intensive than thermochemical and electrochemical processes. The biological process can be divided into two categories: photosynthetic hydrogen production and hydrogen production by dark fermentation. Photosynthetic process produces hydrogen mainly from water and reduces $CO_2$ simultaneously. Dark fermentation is a dark and anaerobic process that produces hydrogen by fermentative bacteria from organic carbon. The article presents a survey of biological hydrogen production processes.

Effect of Pre-Cycling Rate on the Passivating Ability of Surface Films on Li4Ti5O12 Electrodes

  • Jung, Jiwon;Hah, Hoe Jin;Lee, Tae jin;Lee, Jae Gil;Lee, Jeong Beom;Kim, Jongjung;Soon, Jiyong;Ryu, Ji Heon;Kim, Jae Jeong;Oh, Seung M.
    • Journal of Electrochemical Science and Technology
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    • v.8 no.1
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    • pp.15-24
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    • 2017
  • A comparative study was performed on the passivating abilities of surface films generated on lithium titanate (LTO; $Li_4Ti_5O_{12}$) electrodes during pre-cycling at two different rates. The surface film deposited at a faster pre-cycling rate (i.e., 0.5 C) is irregularly shaped and unevenly covers the LTO electrode. Owing to the incomplete coverage of the protective film, this LTO electrode exhibits poor passivating ability. Additional electrolyte decomposition and concomitant film deposition occur during subsequent charge/discharge cycles. As a result of the thick surface film, severe cell polarization occurs and eventually causes cell failure. However, pre-cycling the Li/LTO cell at a slower rate (0.1 C) improves cell polarization and capacity retention; this occurs because the surface film uniformly covers the LTO electrode and provides strong passivation. Accordingly, there is no significant film deposition during subsequent charge/discharge cycling. Additionally, self-discharge is reduced during high-temperature storage.

Effect of Additives on the Contents of Fatty Acid Methyl Esters of Biodiesel Fuel in the Transesterification of Palm oil with Supercritical Methanol (팜유로부터 바이오디젤 연료를 합성하는 초임계유체반응에서 지방산메틸에스테르의 함량에 미치는 첨가물의 영향)

  • Lee, Hong-shik;Choi, Joon-hyuk;Shin, Young Ho;Lim, Youngsub;Han, Chonghun;Kim, Hwayong;Lee, Youn-Woo
    • Korean Chemical Engineering Research
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    • v.46 no.4
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    • pp.747-751
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    • 2008
  • The effect of additives in the synthesis of biodiesel fuel using supercritical methanol was studied in order to examine the possibility of application of spent vegetable oil as a raw material, which has high contents of water or free fatty acid. The experiments were performed by varying the contents of water, free fatty acid or antioxidants respectively in a batch reactor. The contents of fatty acid methyl ester was analyzed by a gas chromatography. As the water contents increased, the contents of fatty acid methyl ester decreased, however, the decrease was very little compared with the alkaline and acid catalyst. The effect of the contents of free fatty acid, vitamin E, and ${\beta}$-carotene was negligible.

Monitoring of Biological Processes by 2-dimensional Fluorescence Sensor (2차원 형광센서에 의한 생물공정의 모니터링)

  • 이종일;정상윤;서국화
    • KSBB Journal
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    • v.16 no.5
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    • pp.493-499
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    • 2001
  • This work presented the monitoring technique of biological processes by a 2-dimensional fluorescence sensor. The 2-dimensional fluorescence sensor can be used to monitor some important variable during cultivation processes simultaneously. In this study we have monitored fermentation processes of a few microorganisms such as recombinant E.coli, A. terreus and T. vulgaris. and investigated the change of the fluorescence spectra in the fermentation processes qualitatively. The 2-dimensional fluorescence sensor can be also used to monitor biochemical reactions and separation processes and applied for the optimization of biological processes.

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Quantitative Frameworks for Multivalent Macromolecular Interactions in Biological Linear Lattice Systems

  • Choi, Jaejun;Kim, Ryeonghyeon;Koh, Junseock
    • Molecules and Cells
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    • v.45 no.7
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    • pp.444-453
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    • 2022
  • Multivalent macromolecular interactions underlie dynamic regulation of diverse biological processes in ever-changing cellular states. These interactions often involve binding of multiple proteins to a linear lattice including intrinsically disordered proteins and the chromosomal DNA with many repeating recognition motifs. Quantitative understanding of such multivalent interactions on a linear lattice is crucial for exploring their unique regulatory potentials in the cellular processes. In this review, the distinctive molecular features of the linear lattice system are first discussed with a particular focus on the overlapping nature of potential protein binding sites within a lattice. Then, we introduce two general quantitative frameworks, combinatorial and conditional probability models, dealing with the overlap problem and relating the binding parameters to the experimentally measurable properties of the linear lattice-protein interactions. To this end, we present two specific examples where the quantitative models have been applied and further extended to provide biological insights into specific cellular processes. In the first case, the conditional probability model was extended to highlight the significant impact of nonspecific binding of transcription factors to the chromosomal DNA on gene-specific transcriptional activities. The second case presents the recently developed combinatorial models to unravel the complex organization of target protein binding sites within an intrinsically disordered region (IDR) of a nucleoporin. In particular, these models have suggested a unique function of IDRs as a molecular switch coupling distinct cellular processes. The quantitative models reviewed here are envisioned to further advance for dissection and functional studies of more complex systems including phase-separated biomolecular condensates.

Amyloid Polymorphism of α-Synuclein Induced by Active Firefly Luciferase

  • Yang, Jee Eun;Hong, Je Won;Kim, Jehoon;Paik, Seung R.
    • Bulletin of the Korean Chemical Society
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    • v.35 no.2
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    • pp.425-430
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    • 2014
  • Amyloidogenic proteins often exhibit fibrillar polymorphism through alternative assembly processes, which has been considered to have possible pathological implications. Here, firefly luciferase (LUC) is shown to induce amyloid polymorphism of ${\alpha}$-synuclein, the major constituent of Lewy bodies found in Parkinson's disease, by acting as a novel template. The drastically accelerated fibrillation kinetics of ${\alpha}$-synuclein with LUC required the nucleation center produced by the active enzyme of LUC. Fluorescent dye binding, transmission electron microscopy, and Fourier transformed infrared spectroscopy revealed the morphologically distinctive amyloid fibrils of ${\alpha}$-synuclein prepared in the absence or presence of LUC. As the altered morphological characteristics became inherent to the mature fibrils, those properties were inherited to next-generations via nucleation-dependent fibrillation process. The seed control, therefore, would be an effective means to modify amyloid fibrils with different biochemical characteristics. In addition, the LUC-directed amyloid fibrillar polymorphism also suggests that other cellular biomolecules including enzymes in general are able to diversify amyloid fibrils, which could be self-propagated with diversified biological activities, if any, inside cells.