• Korean Journal of Microbiology
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• v.52 no.4
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• pp.463-470
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• 2016

The enzymatic degradation of xylans is the most versatile way to obtain the high value-added functional compounds or the fermentable sugars for renewable energy. The endo-${\beta}$-xylanases are the major enzymes which hydrolyze the internal ${\beta}$-1,4-linkages of xylan backbones to produce the mixtures of xylooligosaccharides including xylobiose and xylotriose. Among them, glucuronoxylanase GH30 can exclusively hydrolyze the internal ${\beta}$-1,4-linkages of xylans decorated with methylglucuronic acid branches. In the present study, two xylanolytic enzyme (PaXN_10 and PaGuXN_30) genes were cloned from Paenibacillus amylolyticus KCTC 3005, and expressed in Escherichia coli, respectively. PaXN_10 (38.7 kDa) belongs to the endo-${\beta}$-xylanases GH10 family, while PaGuXN_30 (58.5 kDa) is a member of glucuronoxylanase GH30. They share the same optimal reaction conditions at $50^{\circ}C$ and pH 7.0. Enzymatic characterization proposed that P. amylolyticus can utilize the hardwood glucuronoarabinoxylans via the cooperative actions of xylanases GH10 and GH30. The extracellular PaGuXN_30 is secreted into the medium and hydrolyzes glucuronoarabinoxylans to release a series of aldouronic acid mixtures with a methylglucuronic acid branch. The resultant products being transported into the microbial cell are successively degraded into the smaller xylooligosaccharides by the intracellular PaXN_10, which will be utilized for the cellular metabolism.

• Journal of the Korean Wood Science and Technology
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• v.43 no.3
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• pp.374-380
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• 2015

The quality characteristics of the woodpellet manufactured from two domestic pines (Pinus densiflora S. et Z. and Pinus rigida Mill.) were investigated for the efficient energy use of woody biomass resources. Properties of woodpellets such as moisture content, heating value, ash content, apparent density and durability were determined by using the standard test method of woodpellets of Korea Forest Research Institute (KFRI) and elemental analysis. The results of elemental analysis for C, H, O and N showed 61.42% carbon, 5.56% hydrogen, 32.87% oxygen, and 0.15% nitrogen for Pinus densiflora S. et Z. and 61.03% carbon, 5.96% hydrogen, 32.83% oxygen, and 0.18% nitrogen for Pinus rigida Mill. No significant difference between Pinus densiflora S. et Z. and Pinus rigida Mill was observed on elemental analysis. Heating values of each woodpellet were ranged from 19.00 to 19.42 MJ/kg which satisfied the first grade quality standard (${\geq}18.0MJ/kg$) by KFRI. The ash contents of woodpellet were slightly different between Pinus densiflora S. et Z. and Pinus rigida Mill., and satisfied the first grade quality standard (${\leq}0.7%$) by KFRI. Apparent density of woodpellet (Pinus densiflora S. et Z.) was passed the first grade standard level (${\geq}640kg/m^3$), and woodpellets from Pinus rigida Mill. satisfied the second grade quality of the standard. The moisture contents of each woodpellet were satisfied by the first grade quality standard (${\leq}10%$). The durability of woodpellet (Pinus densiflora S. et Z.) was passed the third grade level (${\geq}95%$), but Pinus rigida Mill. woodpellet was insufficient to satisfy the quality standard.

• Journal of the Korean Wood Science and Technology
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• v.38 no.4
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• pp.323-332
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• 2010

Petroleum-based adhesive resins have extensively been used for the production of wood panels. However, it is necessary to develop environmentally friendly adhesive resins due to the increase of manufacturing cost and the environmental issue, such as the emission of volatile organic compounds, of the pertroleum-based adhesive resins. This study was conducted to formulate environmentally friendly adhesive resins using by rapeseed flour (RSF), which is the by-product of bio-diesel produced from rapeseed, for replacing petroleum-based adhesives with them. To formulate RSF-based adhesive resins, RSF was hydrolyzed in de-ionized water, 1% and 3% sodium hydroxide solutions. As a crosslinking agent, PF prepolymers were prepared with 1.8, 2.1 and 2.4 mol formaldehyde and 1 mol phenol (1.8-, 2.1- and 2.4-PF), and then mixed with RSF hydrolyzates to complete the formulation of RSF-based adhesive resins. The RSF-based adhesive resins were applied to fabricate 3-ply plywood panels. The solid content of RSF-based adhesive resins were ranged from 26.08% to 36.12% depending on the hydrolysis condition of RSF and PF prepolymer type with a high viscosity. The tensile shear strength and wood failure of plywood fabricated with RSF-based adhesive resins exceeded a minimum requirement of KS standard for ordinary plywood regardless of the hydrolysis condition of RSF and PF prepolymer type. Formaldehyde emissions of the plywood panels fabricated with 1.8-PF and RSF hydrolyzates were lower than that of E0 specified in the KS standard. Based on the results, RSF might be used as a raw material of environmentally friendly adhesives for the production of plywood panels, but further researches - the increase of solid content of RSF-based adhesives for reducing press time and the microscopic observation of plywood specimen for identifying the relationship between tensile shear strength and the penetration of adhesives into wood structure - are required to commercialize the RSF-based adhesives.

• Applied Biological Chemistry
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• v.19 no.1
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• pp.36-40
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• 1976

The mucilage of the root of Abelmoschus manihot, MEDIC is important for production of Korean traditional hand-made paper. This study was proceeded to detect the variation of the amount of free reducing sugars and of the viscosity in the mucilage. The results as follow. 1. The mucilage of the root of Abelmoschus manihot, MEDIC has contained some of free reducing sugars, 2. The viscosity of the mucilage isolated from the root decreases with time at the constant temperature, but the amount of reducing sugars show a little change. 3. The amount of the reducing sugars is not changed on the agitation. 4. When $1{\sim}2%$ ammonium sulfate solution is added, the viscosity of the mucilage decreases very gradually, and the amount of the free reducing sugars in the mucilage shows a little change.

• The Korean Journal of Petroleum Geology
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• v.6 no.1_2 s.7
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• pp.25-36
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• 1998

Organic geochemical analyses were carried out in order to characterize organic matter (OM) in the sediments recovered from Korea/japan Joint Development Zone (JDZ V-1, V-3, VII-1 and VII-2) which is located in the northern end of the East China Sea Shelf Basin. Late Miocene sediments from the JDZ V-1 and V-3 wells generally contain less than $0.5\%$ of total organic carbon (TOC). However, early Miocene and Oligocene sediments show TOC values of $0.6-0.8\%$. Middle to late Miocene sediments are rich in TOC up to $20\%$ from JDZ VII-1 and JDZ VII-2 wells. The reason for this rich TOC might be attributed to the presence of coaly shales. Kerogens in the Tertiary sediments from the JDZ series wells are mainly composed of terrestrially derived woody organic matter. Elemental analyses indicate that OM from these wells can be compared to type III. Low hydrocarbon potential and hydrogen index reflect the type of OM. According to the biomarker analyses, the input of the terrestrial OM is prevalent. Oxidizing condition is also indicated by Pristane/Phytane ratio. Samples from the JDZ V-1 and V-3 wells obtain maturities equivalent to the oil generation zone around total depth, and organic matter below 3600 m from JDZ VII-1 and VII-2 wells reached dry gas generation stage. Oligocene sediments below 3500 m in the JDZ VII-1 and JDZ VII-2 wells may have generated limited amount of hydrocarbons, showing a progressive decrease in hydrogen index with depth, due to thermal degradation with increased burial. Gas shows and finely disseminated gilsonite may indicate the generation and migration of the hydrocarbons.

• Journal of the Korean Wood Science and Technology
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• v.43 no.6
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• pp.851-860
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• 2015

The objective of this study was to manufacture the wood based roughage using lumber from thinning of oak and pitch pine (Pinus rigida). And the study also aimed to investigate a feed value evaluation of wood based roughages. To investigate the optimization condition of steam-digestion treatment for roughage, the wood chips of oak and pitch pine were steam-digestion treated at $160^{\circ}C$ under pressure 6 atm depending on treatment times (60 min, 90 min and 120 min) followed by the content of essential oils analyzed. The essential oil content of steam-digestion treated roughages for 90 min and 120 min were under 0.1 mL/kg. The evaluation of feed value was carried out from steam-digestion treated roughages for 90 min through feed chemical composition analysis, NRC (National research Council) modeling, ruminal degradability analysis and relative economic value analysis. The feed chemical compositions including DM (dry mater), CP (crude protein), EE (ether extract), NDF (neutral detergent fiber), ADF (acid detergent fiber), ADL (acid detergent lignin), NFC (nonfiber carbohydrate) in oak roughage were 95.4, 1.36, 3.11, 90.05, 83.85, 17.33, 6.50%, respectively, and in pitch pine roughage were 94.37, 1.33, 5.48, 87.89, 86.88, 30.56, 6.32%, respectively. Both roughages showed low level of protein and very high level of NDF. The TDN (total digestible nutrient) levels using NRC (2001) model in oak and pitch pine roughages were 40.55, 31.22%, respectively. The ruminal in situ dry matter degradability was higher in oak roughage (23.84%) than in pitch pine roughage (10.02%). The economic values of oak and pitch pine rough-ages were 235, and 210 \, respectively.

• Journal of the Korean Wood Science and Technology
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• v.38 no.3
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• pp.213-222
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• 2010

In this study, chemical compositions - holocellulose, lignin and monomeric sugars - were characterized with two poplar wood cell walls, one of which was grown at normal condition (CPW) and the other was genetically modified by antisence suppression of CCoAOMT gene expression (ACPW). Milled wood lignins were isolated from CPW and ACPW and subjected to methoxyl group, DFRC, Py-GC/MS, GPC, $^{13}C$-NMR analysis, respectively. There were few differences in holocellulose contents in both cell walls, which were determined to 81.6% in CPW and to 82.3% in ACPW. However, lignin contents in ACPW was clearly decreased by the suppression of CCoAOMT gene expression. In CPW 21.7% of lignin contents was determined, while lignin contents in ACPW was lowered to 18.3%. The relative poor solubility of ACPW in alkali solution could be attributed to the reduction of lignin content. The glucose contents of CPW and ACPW were measured to 511.0 mg/g and 584.8 mg/g and xylose contents 217.8 mg/g and 187.5 mg/g, respectively, indicating that suppression of CCoAOMT gene expression could be also influenced to the formation of monomeric sugar compositions. In depth investigation for milled wood lignin (MWL) isolated from both samples revealed that the methoxyl contents at ACPW was decreased by 7% in comparison to that of CPW, which were indirectly evidenced by $^{13}C$-NMR spectra and Py-GC/MS. According to the data from Py-GC/MS S/G ratios of lignin in CPW and ACPW were determined to 0.59 and 0.44, respectively. As conclusive remark, the biosynthesis of syringyl unit could be further influenced by antisense suppression of CCoAOMT during phenylpropanoid pathway in the plant cell wall rather than that of guaiacyl unit.

• Journal of the Korean Wood Science and Technology
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• v.38 no.3
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• pp.262-273
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• 2010

In the enzymatic hydrolysis of rice straw and wood meals using extra-cellular enzymes from Fomitopsis palustris, key factors which enhanced the sugar conversion yield were investigated in this work, such as enzyme production and enzyme reaction conditions, surfactant effects, and the surface structure of substrates. F. palustris cultured with softwood mixture produced 12.0 U/$m{\ell}$ for endo-${\beta}$-1,4-gulcanase (EG), 116.68 U/$m{\ell}$ for ${\beta}$-glucosidase (BGL), 18.82 U/$m{\ell}$ for cellobiohydrolase (CBH), and 13.33 U/$m{\ell}$ for ${\beta}$-xylosidase (BXL). These levels of BGL, CBH, and BXL activities were two to four folds more than enzyme activities of F. palustris cultured with rice straw. The optimum reaction conditions of cellulase-RS which produced by F. palustris with rice straw and cellulase-SW which produced by F. palustris with softwood mixture were pH 5.0 at $45^{\circ}C$ and pH 5.0 at $50^{\circ}C$, respectively. The sugar conversion yield of cellulase-SW had the highest value of $40.6{\pm}0.6%$ within 72 h when rice straw was used as substrate. By adding 0.1% Tween 20 (w/w-substrate), the sugar conversion yield of rice straw was increased to 44%, which was about four fifths sugar conversion yield of commercial enzyme, Celluclast 1.5L (Novozyme A/S). A low crystallinity and an intensive fibril surface observed by the scanning electron microscope may explain the high sugar conversion yield of rice straw.

• Journal of Korean Society of Forest Science
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• v.87 no.2
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• pp.276-285
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• 1998

The aboveground biomass and nutrient content (N, P, K, Ca and Mg) of Pinus koraiensis S. et Z., aged 9, 22, 34, 46, 66 years, were measured in the Experiment Forest of Kangwon National University of Kangwondo province. The site index of the stands ranged from 13.5 to 14.2. Allometric equations (logY=alogX+b, where Y, X is ovendry mass and DBH, respectively) relating dry weights of stem, branches and needles to diameter at breast height (DBH) were developed to estimate aboveground tree biomass. Total above ground tree biomass increased with stand age from $21.8t\;ha^{-1}$ in the 9-year-old stand to $130t\;ha^{-1}$ in the 66-Year-old stand. Aboveground biomass was allocated as follows : stem> branch > foliage, except for the 9-year-old stand which had a greater proportion of foliage biomass than branch biomass. As stand age increased, an increasing proportion of annual biomass increment was allocated to stems. The aboveground biomass of shrubs and herbs ranged from 0.4 to $3.9t\;ha^{-1}$ and from 0.05 to $0.6t\;ha^{-1}$, respectively. No relationship was found between aboveground understory biomass and stand age. The mass of woody debris and forest floor varied between 0.59 to $1.54t\;ha^{-1}$ and 6.0 to $21.63t\;ha^{-1}$, respectively. Nutrient accumulation in aboveground tree biomass increased with stand age and was in the order of N > Ca > K > P > Mg. Average rates of nutrients accumulation in biomass were greatest in the early stages of stand development, and less marked as stand aged. The nutrient concentrations in different tree components decreased in the order of needle > branch > stem. There were no detectable trends in nutrient content of the forest floor and mineral soils with stand age. Understory vegetation contributed little to the nutrient pool of these Korean pine ecosystems. Mineral soil contained the Breast proportion of nutrient capital of the various ecosystem compartments.

• Archives of design research
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• v.19 no.4 s.66
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• pp.133-144
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• 2006

According to the latest report by the Customer Protection Board, those who moved into newly constructed buildings are complaining about unidentified pains, asking for more careful selection of constructive materials for prevention of such potential problems. It is internationally recognized today that ecological materials can serve a significant factor for users' health, environmental protection and better industrial competitiveness. This study examined eco-design aspects of each interior material through web site search, in order to help customers learn about and capitalize on eco materials in a proper manner. As a result, 1. It turned out that the domestic industry are giving an impetus to releasing new eco items focusing on lower VOCs emission or addition of functional components as part of the marketing strategy. However, it is recommended that company understand significance of life cycle, and produce eco-concept materials. 2. The reliable standard for choosing the domestic material is EL, HB, GR marks. It is desirable to enhance recycling technologies and expand the sustainable consumption. customer class, since many recycled items are not developed. 3. The sourcing is a vulnerable part in terms of the concept of being environment-friendly material. Therefore, many manufacturers should design the easy knock-down products and produce the good items using recycled materials instead of new raw materials. Also solutions for making the energy from burning material should be studied. 4. The guidebook or manual with correct information about eco-materials is required to promote production and consumption with sustainable concept. 5. Many manufacturers are emphasizing ecological materials for customers, but some of them intended to disrupt customers' proper selection by promoting even unverified items to be environment-friendly.