• Journal of the Korean Wood Science and Technology
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• v.44 no.2
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• pp.231-240
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• 2016

The change in chemical compositions of leachate and medium density fiberboard (MDF) from a laboratory-scale simulated landfill which constructed in a plastic container containing alternating layers of soil and MDF was investigated to evaluate decomposing of MDF in soil. Four treatments were conducted: 1) MDF in soil, 2) MDF only, 3) cured UF resin in soil, and 4) soil only. Molecular weight (MW) distribution of compounds in leachate from soil only treatment did not change over time. In UF resin in soil treatment, the MW distribution shifted to a lower MW distribution over time, while the peak shifted to the left indicated changing to higher MW distribution in leachate from treatment 1 and 2 contained MDF. Higher percent nitrogen in leachate was observed in MDF containing treatments due to the UF resin in the MDF. The percent carbon slightly increased in MDF only while that greatly decreased in MDF in soil treatment maybe due to bacterial activity. The percent of extractable materials from the MDF decreased greatly on day 35 compare to day 0, and subsequently did not change much on day 77. In contrast, percent holocellulose and lignin did not change much over time. No structural change of the wood fiber in MDF occurs during the study. Water-soluble materials from MDF in soil contributed the change in chemical composition of leachate.

• The Korean Journal of Ecology
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• v.21 no.1
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• pp.73-80
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• 1998

Peroxidase has been isolated to apparent homogeneity from earthworm, Lumbricus rubellus, using ammonium sulfate fractionation, Sephacryl S-2000 gel filtration, CM-cellulose cation exchange chromatography and native-PAGE elution. Some of its enzymatic characteristics were examined. The optimum pH for gruaiacol oxidation of earthworm peroxidase was determined to be 6.0, and the $K_{m}$ values against guaiacol and $H_2O_2$ were 1.25 mM and 3.4mM, respectively. When various compounds were tested as the possible substrates of the enzyme, o-dianisidine was used as the substrate. However, earthworm peroxidase could not oxidize esculetin and ferulic acid as substrates, suggesting the different characteristics of the enzyme from plant peroxidases. The optimum pH for veratryl alcohol and $H_2O_2$ oxidation was determined to be 2.5 when lignin peroxidation activity was examined. The $K_{m}$ values for veratryl alcohol and $H_2O_2$ were 0.02 mM and 0.13 mM, respectively. Furthermore, the earthworm peroxidase could oxidize phenoxyherbicides such as 2,4-D, 2,4-DP and MCPA as substrates. The optimum pHs for 2,4-D, 2,4-DP and MCPA were determined to be 4.0, 2.0 and 2.0, respectively. The most available substrate was 2,4-DP, followed by MCPA and 2,4-D when their peroxidation activities were compared.

• Environmental Engineering Research
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• v.23 no.4
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• pp.390-396
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• 2018

This study investigated the transformation of dissolved organic matter (DOM) in a free-water surface flow constructed wetland. Pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) coupled with preparative high-performance liquid chromatography (prep-HPLC) was used to analyze the compositions of biopolymers (polysaccharides, amino sugars, proteins, polyhydroxy aromatics, lipids and lignin) in DOM according to the molecular size at three sampling points of the water flow: inflow, midflow, and outflow. The prep-HPLC results verified the decomposition of DOM through the decrease in the number of peaks from three to one in the chromatograms of the sampling points. The Py-GC/MS results for the degradable peaks indicated that biopolymers relating to polysaccharides and proteins gradually biodegraded with the water flow. On the other hand, the recalcitrant organic fraction (the remaining peak) in the outflow showed a relatively high concentration of aromatic compounds. Therefore, the ecological processes in the constructed wetland caused DOM to become more aromatic and homogeneous. This indicated that the constructed wetland can be an effective buffer area for releasing biochemically stable DOM, which has less influence on biological water quality indicators, e.g., biochemical oxygen demand, into an aquatic ecosystem.

• Food Science and Preservation
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• v.22 no.4
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• pp.512-519
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• 2015

In this study, the effects of gamma-radiation treatment on cell wall composition and physiological characteristics of astringent persimmon fruit were investigated. The soluble tannin contents of gamma-radiated samples were reduced by the radiation treatment. The hardness of the radiated fruit was decreased when compared to non-radiated fruit. Alcohol-insoluble component of the cell wall in the radiated fruit was decreased from 39.3 mg/g to 37.2 mg/g. The water-soluble content of the radiated fruit was increased from 11.4 mg/g to 13.9 mg/g. The cell wall content of the non-radiated fruit was 26.6 mg/g whereas the cell wall content of radiated fruit was decreased to 23.1 mg/g. Due to the maturation of astringent persimmon fruit by gamma-radiation, water-soluble compounds were increased whereas decreasing in cell wall compounds. The contents of lignin, pectin, and cell wall were decreased from 0.82 mg/g and 3.56 mg/g to 0.77 mg/g and 3.14 mg/g, respectively. Acid-soluble hemicellulose content was decreased by gamma-radiation, while alkali-soluble hemicellulose and cellulose contents were increased. Activities of sotening enzyme as polygalacturonase, pectinesterase and $\beta$-galactosidase existed in persimmon fruit were increased by gamma-radiation. In the sensory evaluation, gamma-radition treated persimmon showed very low astringent taste when compared to the non-radiated fruit. In hardness test, the non-radiated persimmon maintained the hardness while gamma-treated persimmon showed softened outer layer due to the condensation of tannin during radiation treatment. Therefore, gamma-radiation treatment will be used for the removal of its astringency of persimmon fruit and for enhancement of its maturation.

• Journal of Life Science
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• v.22 no.8
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• pp.1092-1098
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• 2012

This study was carried out to discover the skin wrinkle reducing components in the seeds of Arctium lappa. The isolation of a methylene chloride-soluble fraction of 70% ethanol extract from the seeds of Arctium lappa using a procollagen type-1 synthesis and MMP-1 activity resulted in the isolation and identification of four lignin compounds: arctiin, arctigenin, matairesinol, and diarctigenin. All structures were confirmed via NMR and MS spectroscopic data. To determine cell viability and procollagen type-1 synthesis, human dermal fibroblasts were treated with 10-100 ${\mu}M$. As a result, none of the four compounds showed cytotoxicity up to 50 ${\mu}M$. We also investigated their procollagen type-1 synthesis and MMP-1 inhibition activity and found that arctiin had the highest activity in terms of both procollagen synthesis and MMP-1 inhibition among all four compounds. Putting all the data together, we suggest that arctiin be used in cosmetics as an anti-wrinkle material.

• Korean Journal of Environmental Agriculture
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• v.20 no.4
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• pp.238-243
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• 2001

Mass reduction and physicochemical properties of the produced compost were investigated during composting domestic food wastes without additive. A small composter used in this study had the height of 15 cm from the center of bottom half circle (diameter 24 cm) up to under the lid, the side length of 50 cm and the horizontal lid angle of $50^{\circ}$ and was operated at the heating unit temperature of $85^{\circ}$. It was mixed by the rotating arm for two minutes in every half hour while supplied with air flow at 3 L/min for 10 minutes in every half hour. This condition was found in a preliminary experiment as optimal for keeping the water content of composting material in the optimal range without adding any bulking materials. The domestic food wastes were added into the composter at the rate of 1 kg/day without additives during composting. The results were as follows; during the composting process, water content maintained in the range of $51.0{\sim}53.5%$. Hemicellulose and lignin contents did not show any tendency, but cellulose content decreased. During the composting process, $NH_3-N$ and $NO_2-N$ were not detected due to nitrification. The contents of inorganic compounds did not increase during the composting process. They were in the range of $1.32{\sim}1.71%\;P_2O_5$, $1.29{\sim}1.48%\;CaO$, $0.41{\sim}0.49%\;MgO$, and $0.38{\sim}0.74%\;K_2O$. For 20 days, weight reduction rate was 67.5% in wet basis, and decomposition rate was 48% in dry basis. Concentration of heavy metals (Cu, Cr, Cd, Pb, Zn, Hg, As) was less than the limiting value of the compost. Maturity of the produced compost was 3 grade through reaching maximum temperature of $46{\sim}48^{\circ}C$.

• The Korean Journal of Mycology
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• v.40 no.2
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• pp.98-103
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• 2012

This study has been conducted to screen the decolorization of 4 aromatic synthetic dyes and production of ligninolytic enzymes by 4 white rot fungi such as Bjerkanderia adusta, Cerrena unicolor, Pleurotus pulmonarius and Abortiporus biennis. It was found that B. adusta, C. unicolor, and P. pulmonarius have the ability to efficiently decolorize congo red and moderately decolorized amaranth and orange G in solid and liquid culture media. However, the decolorization rate of 4 synthetic dyes by A. biennis was relatively low. The decolorization of congo red, amaranth, orange G were related to the growth rate of the fungal mycelia in the solid medium. But, the all fungi tested did not efficiently decolorize methylene blue in the liquid culture media. To investigate the production of ligninolytic enzymes in media containing aromatic compounds, fungi were cultured in 1% naphthalene supplemented potato dextrose broth medium. All fungi tested had the capability to produce laccase, lignin peroxidase and manganese peroxidase, and B. adusta was the best ligninolytic enzymes producing white rot fungus among other fungi tested.

• Journal of the Korean Wood Science and Technology
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• v.40 no.3
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• pp.204-211
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• 2012

In this study, fast pyrolysis of pitch pine (Pinus rigida) was performed in a fluidized bed reactor under the temperature ranges between 400 and $550^{\circ}C$ at the residence time of 1.9 sec. Essential pyrolytic products (bio-oil, biochar, and gas) were produced and their yield was clearly influenced by temperature. The maximum yield of bio-oil was observed to 64.9 wt% (wet basis) at the temperature of $500^{\circ}C$. As pyrolysis temperature increased, the yield of biochar decreased from 36.8 to 11.1 wt%, while gas amount continuously increased from 16.1 to 33.0 wt%. Water content as well as heating value of bio-oils were obviously sensitive to the pyrolysis temperature. The water contents in the bio-oil clearly decreased from 26.1 ($400^{\circ}C$) to 11.9 wt% ($550^{\circ}C$), with increasing the fast pyrolysis temperature, while their higher heating values were increased from 16.6 MJ/kg to 19.3 MJ/kg. According to GC/MS analysis, 22 degradation compounds were identified from the bio-oils and 10 compounds were derived from carbohydrate, 12 compounds were derived from lignin.

• Korean Journal of Medicinal Crop Science
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• v.26 no.2
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• pp.127-133
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• 2018

Background: The demand of recycling renewable agricultural by-products is increasing. Radiation breeding is a method used to improve saccharification efficiency. Thus, we investigated the effect of gamma ray irradiation on the pretreatment and enzymatic hydrolysis of the stalks of Senna tora, an important medicinal plants. Methods and Results: S. tora seeds were irradiated with gamma ray at doses of 100, 200, 300, and 400 Gy. In the pretreated biomass, glucan and lignin content were higher in the M1 ($1^{st}$ generations of irradiation) S. tora stalks than in the M2 ($2^{nd}$ generations of irradiation) stalks, this can be explained by the higher degradation rate in M1. After oxalic acid pretreatment, the concentration of total phenolic compounds (TPCs) in the hydrolysate increased in the gamma ray treated seeds. The highest relative increase rate in crystallinity in the pretreated biomass was observed in M1-400 Gy and M2-100 Gy. The cellulose conversion rate was higher in M1 than in M2, except for 200 Gy. Conclusions: Gamma ray irradiation at an appropriate dose can be used to improve the efficiency of pretreatment and enzymatic hydrolysis, thereby increasing biomass availability.

• Journal of the Korean Wood Science and Technology
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• v.23 no.4
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• pp.27-32
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• 1995

To understand whether ligninolytic enzyme catalyze polymerization or depolymerization of the high molecular weight (HMW) lignin, the action of laccase and Mn-peroxidase (MnP) towards commercial ligninsulfonates (LS) was examined in various conditions of pH and cosubstrates. Polymerization occurred when LS was incubated with laccase at pH 6.0. In contrast, the high molecular weight portions were significant1y reduced at pH 4.5, especially when glucose was added. When LS was treated with MnP at pH 4.5, compounds of low molecular weight were produced. In particular, when cellobiose was added to Mn-P reaction mixture, the breakdown of LS was observed. In conclusion, degradation of LS by laccase and MnP occurred primarily at pH 4.5 where-as polymerization of LS was dominant at pH 6.0. Color index, however, was not greatly changed in the degradation mixtures of LS.