• Title/Summary/Keyword: chemical ecology

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Microbiological Purification of L-Arabitol from Xylitol Mother Liquor

  • Jiang, Mingguo;Wang, Ben;Yang, Lifang;Lin, Shuangjun;Cheng, Hairong
    • Journal of Microbiology and Biotechnology
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    • v.21 no.1
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    • pp.43-49
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    • 2011
  • As a rare sugar alcohol, L-arabitol can be used in food and can prevent extra fat deposits in the intestinal tract. Commercially, L-arabitol is prepared from pure L-arabinose by hydrogenation, which needs a high temperature and high pressure, leading to a high production cost for Larabitol. Therefore, this study describes a novel L-arabitol production method based on biological purification from the xylitol mother liquor, a cheap and readily available raw material that contains a high concentration of Larabitol. First, a novel Bacillus megaterium strain was screened that can utilize xylitol, sorbitol, and mannitol, yet not L-arabitol. The isolated strain was inoculated into a medium containing the xylitol mother liquor under formulated culture conditions, where a high L-arabitol yield (95%) and high purity (80%) were obtained when the medium was supplemented with 50 g/l of xylitol mother liquor. Upon further purification of the fermentation broth by ion exchange and decolorization, L-arabitol was crystallized with a purity of 98.5%.

Graphite Furnace Atomic Absorption Spectrophotometric Determination of Trace Horseradish Peroxidase Using Nanosilver

  • Jiang, Zhi-Liang;Tang, Ya-Fang;Wei, Lin;Liang, Ai-Hui
    • Bulletin of the Korean Chemical Society
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    • v.32 no.8
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    • pp.2732-2736
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    • 2011
  • In pH 4.2 HAc-NaAc buffer solution, horseradish peroxidase (HRP) catalyzed $H_2O_2$ oxidation of nanosilver to form $Ag^+$. After centrifugation, $Ag^+$ in the supernatant can be measured by graphite furnace atomic absorption spectrophotometry (GFAAS) at the silver absorption wavelength of 328.1 nm. When HRP concentration increased, the $Ag^+$ concentration in the supernatant increased, and the absorption value enhanced. The HRP concentration in the range of 0.84-50 $ng{\cdot}mL^{-1}$ was linear to the enhanced absorption value (${\Delta}A$), with a regression equation of ${\Delta}A$=0.012C+0.11, correlation coefficient of 0.9988, and detection limit of 0.41 $ng{\cdot}mL^{-1}$ HRP. The proposed GFAAS method was used to detect HRP in waste water samples, with satisfactory results.

BioRational Approaches for Insect Control

  • Bowers, William-S.
    • Korean journal of applied entomology
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    • v.31 no.3
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    • pp.289-303
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    • 1992
  • Investigation of the environmental impact of widespread pesticide use has revealed a virtue/vice relationship. Although many pesticides perform their function and disappear without harm to the environment, others persist beyond their useful purpose and cause direct of indirect hazard to man, domestic animals and wildlife. Concurrently, many pests have rapidly adjusted to chemical control practices through changes in behavior that avoid exposure to pesticides of throuth genetic selection for populations resistant to the toxicants. The prospect of losing control over insect herbivores and desease vectors and returning to the days of global hunger and disease is unthinkable. Fortunately, from basic studies of insect and plant biology many opportunities for the development of safe, selective and environmentally pacific strategies for insect pest management are being realized.

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Study on the Nanofiltration of Various Dye Solutions (NF막에 의한 다양한 염료용액의 막분리 특성)

  • Yang, Jeongmok;Kim, Tak-Hyun;Park, Cheolhwan;Kim, Jeehyeong;Kim, Sangyong
    • Clean Technology
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    • v.10 no.1
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    • pp.37-45
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    • 2004
  • This study examined the separation characteristics of some of the most commonly used disperse, reactive and acid dyes by nanofiltration membrane. The chemical characteristics of three major dye solutions such as chemical oxygen demand, total nitrogen, total organic carbon, color, suspended solids, total dissolved solids, conductivity were investigated in this work. Experiments showed that the types of dye had a significant effect on both permeate flux and rejection efficiencies mainly due to the differences among their chemical structures and natures. Especially, the nanofiltration of reactive dye solutions showed higher permeate flux, lower total dissolved solid rejection efficiency and higher organics rejection efficiency than those of disperse dye solutions.

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Surface Modification of PET Irradiated by Ultra-Violet (Part I) -Transformation of Chemical Structure and Surface Properties- (UV조사를 통한 PET의 표면개질 (제1보) -화학구조 변화 및 표면특성 변화-)

  • Choi Hae Young;Lee Jung Soon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.29 no.3_4 s.141
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    • pp.561-568
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    • 2005
  • The irradiation of Ultra-Violet (UV) is an efficient treatment for polymer to improve hydrophilic properties. 4-Channel PET knit fabrics were treated with UVA and UVC to develop functional and environment-friendly fabric. The fabric was treated with various treatment times and distances from UV lamps having different wavelength. FT-IR and XPS investigated the chemical changes. To confirm the change of surface properties, contact angle, surface energy and SEM were examined. The study of UV as a treatment for PET knit fabric shows significant changes in chemical and surface properties, which is proved by analyses. FT-IR and XPS analyses prove the augmentation of carboxylic, Hydrophilic groups on the surfaces treated by UV. The increase of water contact angle and surface energy means more water wettable and surface energy of PET film was substantially increased by UV irradiation time. The ageing after surface treatment had little influence on the surface energy of the irradiated PET film. SEM proves the surface modification of PET such as etching, bubble and crack. The negative effects are increased in accordance with increasing treatment time.

Distribution characteristic of invasive alien plants in Jeju Island

  • Ryu, Tae-Bok;Kim, Mi-Jeoung;Lee, Chang-Woo;Kim, Deok-Ki;Choi, Dong-Hui;Lee, Hyohyemi;Jeong, Hye-Ran;Lee, Do-Hun;Kim, Nam-Young
    • Journal of Ecology and Environment
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    • v.41 no.6
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    • pp.173-181
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    • 2017
  • Background: This study was undertaken to analyze the distribution and ecological characteristics of invasive alien plant species on Jeju Island, and to provide basic data for their management and control. Results: A field research was conducted at 436 locations on Jeju Island. The field research identified nine species of invasive alien species growing on Jeju Island. Based on the distribution pattern, Hypochaeris radicata L., Rumex acetosella, and Ambrosia artemisiifolia L. were found to be distributed horizontally throughout Jeju Island, with vertical growth in two or more vegetation zones, from warm temperate to the subalpine zone. Widely distributed species penetrate various habitats, such as grasslands, ranches, roadsides, farmlands, and empty lots, and have an immensely negative impact on the ecosystem, including declining biodiversity on Jeju Island. Paspalum distichum var. indutum Shinners, Paspalum distichum L., Solanum carolinense L., and Aster pilosus Willd. were distributed in some areas as a biased distribution species, whereas Lactuca scariola L. and Solidago altissima L. were found only in certain areas as centralized distribution species. Conclusions: The centralized distribution species and biased distribution species of the invasive plants in the ecosystem of Jeju Island should be physically eliminated, keeping in mind the short- and mid-term perspectives and monitoring, and by considering expansion of additional distribution areas. Due to limitations of physical/chemical elimination, time, and cost, widely distributed species require to be eliminated and managed, mainly to restore the integrity of the ecosystem, by planting native species to reestablish the habitat.

One-Step Enzymatic Synthesis of Blue Pigments from Geniposide for Fabric Dyeing

  • Cho, Y.J.;Kim, S.Y.;Kim, J.;Choe, E.K.;Kim, S.I.;Shin, H.J.
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.3
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    • pp.230-234
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    • 2006
  • In this study, we describe a one-step chemoenzymatic reaction for the production of natural blue pigments, in which the geniposide from Gardenia extracts is transformed by glycosidases to genipin. Genipin is then allowed to react with amino acids, thereby generating a natural blue pigment. The ${\beta}-glycosidases$, most notably Isolase (a variant of ${\beta}-glucanase$), recombinant ${\beta}-glycosidases$, Cellulase T, and amylases, were shown to hydrolyze geniposide to produce the desired pigments, whereas the ${\alpha}-glycosidases$ did not. Among the 20 tested amino acids, glycine and tyrosine were associated with the highest dye production yields. The optimal molar ratio of geniposide to glycine, two reactants relevant to pigment production, was unity The natural blue pigments produced in this study were used to dye cotton, silk, and wool. The color yields of the pigments were determined to be significantly higher than those of other natural dyes. Furthermore, the color fastness properties of these dyes were fairly good, even in the absence of mordant.

Synthetic Detergent and our Daily Lives as Consumers against Environmental Pollution. (환경오염과 합성세제에 대한 소비생활)

  • Lee, Eun-Kyung
    • Korean Journal of Human Ecology
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    • v.4 no.1
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    • pp.123-133
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    • 1995
  • Lately our environments have been destroyed by such new things as synthetic detergent. How to use detergent at home can be a decisive factor for decreasing water pollution because living sewage by using detergent at home is the main cause of water pollution. We consumers, therefore, should understand the relation between the chemical ingredients of detergent and water pollution and should choose detergent always taking the kinds of detergent, its washing pewer into consideration. We should also contribute to the protection of out environment by keeping the standard of using amount attached to the products.

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