Earticle

Cinnamomum camphora (Lauraceae) is an evergreen broad-leaved tree and distributed in the south of China and Japan. This species has been widely cultivated in many countries because of its aromatic oils, insect-repellent effects and ornamental value. Despite its vast utilization and cultivation, little is known about its genetic diversity and population genetics. To date, only a few genomic simple sequence repeat (SSR) markers were developed in C. camphora and no genic-SSR primers were available yet. Thus, it is necessary to develop more genic-SSR markers, which will facilitate the genetic studies of Cinanamomum. In this study, a total of 74,289 simple sequence repeats (SSRs) were found in 56,124 unigenes, of which 14,225 unigenes contained more than one SSR locus. Among these SSR loci, the mono-nucleotide repeats were the most frequent, with a frequency of 61.14%, followed by 24.87% di-nucleotide repeats and 12.87% tri-nucleotide repeats. Twenty-one polymorphic SSR markers were developed and validated in 45 camphor trees. The 21 loci were further examined for genetic diversity of 38 provenances, 190 individuals in the whole natural distribution area of camphor tree in China. The results showed that 74 polymorphic sites were detected with average 2.74 polymorphic were detected for each prime. The means of observed and expected heterozygosities were 0.4446 and 0.4419, respectively. Nei's and Shannon’s information index for these populations were 0.4400 and 0.7193, respectively. The genetic similarity coefficient of 38 provenances was between 0.05 and 0.95, with an average of 0.17.The smallest genetic distance is JXWY and JXRJ and the genetic distance between JXTG and GZDZ was the largest. Cluster analysis in 0.88 genetic distance can divide into five groups. Jiangxi provenances clustered into two groups, of which JXAY grouped into one group and other provenances grouped into another group. Other provenances of China grouped three small branches: CQYY and HNHH, GZDZ and SCLZ, and other provenances. The clustering results showed that the genetic components of camphor tree in China had obvious regional features. The analysis of molecular variance exhibited that 77% of genetic variation was observed within the populations. The novel genic-SSR markers will not only benefit genetic diversity analysis and wild resources conservation of C. camphora, but also contribute to exploring the further evolutionary history and genetic differentiation pattern of Cinnamomum.

Feces of wild animals are the harbor and potential vectors of Salmonella and Shiga toxinproducing Escherichia coli (STEC) that cause many infectious diseases of human and animals. This study includes the molecular phylogeny and median joining network (MJN) of Salmonella and STEC. Based on median joining network and haplotype analyses, 10 Salmonella haplotypes were clearly discovered in Korean wild animal fecal samples. Of them, the haplotype H8 and H1 belong to S. enterica diarizonae and the other 8 haplotypes belonged to S. e. enterica. The haplotype H7, H6 and H9 (green color) of birds, H4 and H5 (red color) of leopard cats and H13 of Korean National Culture Collection (NCCP) might be disseminated from same origin. The phylogentic tree shows that a total 54 Salmonella strains from worldwide and Korea were grouped into main two species of S. enterica and S. bongori. Salmonella enterica formed separated clades of four subspecies of S. e. enterica, S. e. salamae, S. e. arizonae and S. e. diarizonae. In case of STEC, 6 types of serovas were discovered from the 93 samples. Strains of the serovar E. coli 083:H1 were well clustered genetically together and widely distributed over various localities and various host species. This kind of analysis might be better understanding of genetic relatedness of Korean Salmonella to others. In addition to gene network analysis more important part of this section because of genealogical analysis might be understanding transmission mode of pathogen

Each mountain village has its own peculiar ecosystem composed of human society, forest and various living things. Usually, human activities deeply affect forest. An example would be that poor residents often damage forest in order to maintain their livelihood. For the sustainable development of mountainous regions in developing countries, it is required to prepare development strategies that meet cultural and ecological characteristics of the region. To meet such requirement, United Nations recently suggested SDGs (Sustainable Development Goals) which are the collection of 17 global goals covering most aspects of human life. The SDGs are considered as representative guidelines of ODA (Official Development Assistance). The purpose of this talk is to seek interdisciplinary cooperation to achieve SGD1, 'No Poverty' especially in mountainous regions. The first step of it is to share experience of KOPIA (Korea Program on International Agriculture) implemented by Korean government. To reduce rural poverty and to guarantee food security by increasing agricultural productivity, RDA (Rural Development Administration) has established 21 KOPIA centers all over the world. Those centers has been trying to develop and distribute regionally appropriate agricultural technology. Although the activities of KOPIA are mainly focused on agricultural areas, KOPIA also has a lot of experience in mountainous areas and highlands where many low-income farmers live. For example, KOPIA has introduced techniques to grow vegetables which is suitable to cooler climate. And KOPIA has often built virus free seed-potato production base in highlands. In Southeastern Asia including Cambodia and Laos, small farmers are very interested in sericulture. Sometimes desirable agricultural practices are very useful to protect forest. Some areas of Latin America suffer from deforestation due to excessive grazing. By making suitable grassland, it is not only useful to prevent deforestration but also very effective to increase livestock productivity. In the future, we need to focus on ecologically valuable agricultural methods such as agoforesty. In addition, it is available to distribute agricultural technology suitable to raise the income of the residents near the large-scale economic tree plantations.

SFTS (Severe Fever and Thrombocytopenia Syndrome) is one of tick-borne diseases that RNA virus causes high fever vomiting, diarrhea, coma, and multiple organ failure. Since SFTSV was initially reported in 2011 in China, the Korea Centers for Disease Control (CDC) designated the SFTSV as the legal communicable disease county 4 in 2013. Infection occurs mainly during the period of June to October, and the numbers of infected people has increased every year. Older person have shown higher infection for SFTS, and SFTSV seroprevalence was 3-fold higher for rural farmers. Haemaphysalis longicornis reported as vector of SFTS is three-host tick, which has developmental stages of larvae, nymphs, and adults. The species who is distributed throughout Korea, has the habit climbing to the plant and waiting for host. Except for the time attached to the host animals, they usually live on the ground or plants. Their eggs hatch on ground under herbaceous plants in woody tree forests. All wildlife which include mammals, amphibians and avian, as well as livestock such as cattle, can become tick hosts. Host presence is driving force to affect tick lifecycle like survival, development, reproduction, dispersal. Thus, it is reported that number of infected tick or number of human infections are positively correlated with the density of roe deer in Europe. Wildlife, especially invasive mammal to human area, can be an important vector of H.longicornis who causes SFTSV. The purpose of this research is to identify the role of wildlife in the spread of tick-bone disease (SFTS) to human.

Recently, RIFA (Solenopsis invicta) was detected six times during 2017 to 2018 in port area, Korea. They were discovered by plant quarantine inspectors and disinfected by government control team including Animal and Plant Quarantine Agency, Rural Development Agency, the Ministry of Environment and theMinistryofOceansandFisheries, etc. However, RIFA colony invasion possiblity is increasing according to world trading of commodities. If RIFA would invade in to forest area, it will attack on small animals(insects, frogs and so on) and threaten to forest Biodiversity.

As the Paris Convention on Climate Change takes effect as international law, Korea should reduce 37% greenhouse gases emission Business As Usual (BAU) by 2030. Because Forestry biomass is a carbon-neutral fuel and can be used for conventional thermal power plant, interest of forestry biomass have been increasing. But comparing with coal, its calorific value is low and it makes lots of impurities during combustion. So, in order to use this biomass more efficiently, torrefaction process would be suggested Torrefaction is the process which makes the energy density higher under low temperature (200℃~300℃), a relatively short time (10~60 minutes) and lean or without oxygen condition. After torrefaction process, biomass has the benefit as follows: increased calorific value of biomass, increased water resistance, and advantages of storing and transporting by mass reduction. But characteristics of biomass rely on process time and temperature and there is not enough analysis of process condition. In this study, a mass reduction and heating value prediction model during the torrefaction process was established and characteristics as fuel (hydrophobic property, calorific value) were analyzed. Using wood pellet, torrefaction experiments were performed at 200℃, 230℃, 270℃. After process, to prevent rapid reaction with oxygen, amount of mass reduction was measured after 30minutes cooling. From the experiments, 7.24~31.21% of mass reduction and 4880~5400kcal/kg of heating value were achieved under the different setting temeprtures and times. In simulation, mass reduction and heating value were observed in the range of 3.07~40.24% and 4748~6014kcal/kg respectively which were good agreement with the experimental results.

Bamboo Fiber Reinforced Composites (BFRC), is a novel kind of engineering bamboo-based composites developed by Research Institute of Wood Industry, Chinese Academy of Forestry. This material has the advantage of controllable performance, adjustable specifications, designable structures, environmentally friendly and regeneration which makes a perfect substitute for high quality hardwood, which can be utilized in fields of flooring, furniture, interior and outdoor decoration, construction, wind turbines, and other engineering applications. The manufacturing technique of BRFC is widely promoted in many companies of 12 provinces.

Recently, as increasing of demand for passive house and green house as low energy green building, development of lightweight insulation materials by using natural resource will be an important part for establishing green building technology in the future. Wood fiber insulation board (WFIB) can be a one of the key material for low energy consumption, comfortable, and safety construction of residential space because of its eco-friendly and high thermal insulation performance. This study was carried out to compare the characteristics of WFIBs manufactured with different conditions. WFIBs (20 mm (T), 0.10 g/cm3) were successfully manufactured by melamine-urea-formaldehyde (MUF), phenol-formaldehyde (PF), and emulsified MDI (eMDI), and latex resins. Thermal conductivities of all WFIBs were 0.037 W/m∙K which was similar insulation performance with extruded polystyrene foam. A 20, 25, 30, and 35% resin contents of melamine-urea-formaldehyde (MUF) was used for preparing of WFIB and then their properties were compared. There was almost no effect on the insulation performance of WFIBs. To investigate optimum density, WFIBs were prepared in 0.10, 0.15, 0.20 and 0.25 g/cm3. The higher thermal conductivity (0.037 W/m∙K) was observed on the WFIB at 0.15 g/cm3 density, and thermal conductivity tended to gradually increase to 0.043 ~ 0.046 W/m∙K as density increase. The optimum conditions of WFIB could be about 0.15 ~ 0.20 g/cm3 density with 25% resin contents of MUF for securing both insulation performance and human body and structural safety.

Termites are a serious menace to wooden structures because the wood structure damaged by termites has loses its function and structural instability. Damage from termites has been continuously reported in Korea because of the rapid growth of termites caused by global warming and imported wood. Various termite control methods have been developed to prevent and control the infestation of termites. Among them, the surface treatment is the most widely used method in Korea. However, it has difficulties to work with due to strong scent of the anti-termite agents and cause harm to anyone at home during or after the application. Therefore, it has become necessary to search eco-friendly control method other than surface treatment. In this study, termite control trap, which can be installed directly on wooden structures to remove infiltrated termites, was developed to evaluate the termite attraction and baiting ability of the termite. The species used in this study was Reticulitermes speratius which inhabits in Korea. The trap was fabricated into triangular shapes so it can suitable on the corners of the wooden structure. The various components were used to evaluate the termite attraction and termiticidal efficacy. Also, a hydroscopic felt dyed with Nile Blue A was used to evaluate the baiting ability of termites. As a result, it was confirmed that Bistrifluron was effective not only on the termiticidal effect but also on the baiting ability. Bistrifluron was selected as the best component of termiticide for termite control trap. It was suggested that the new termite control trap can directly attack the termites in the wooden structure.

Sustainable development is not possible without the provision of sustainably produced energy. Thus the development and utilization of renewable energy is an essential part of sustainable development goals and the Paris Climate Change Agreement. In this context, Indonesia has committed to expanding renewable energy and to reducing greenhouse gas emissions by 29% by 2030. To identify the potential of sustainable biomass production on degraded or marginal land for energy production, supporting rural livelihood and rehabilitation of degraded land, the NIFoS-CIFOR collaborative team has been ongoing work in Central Kalimantan, Indonesia since 2016. Study site is located in the middle of peatland of Pulang pisau district. This area was damaged by peat fire in 2015. Due to this, this land was abandoned by land owner. In 2-ha test land, 5 tree species such as Calophyllum inophyllum, Gliricidia sepium and Pongamia pinnata for biodiel and Calliandra calothyrsus and Reutealis trisperma for biomass, were planted in order to find out suitable species on this degraded peat land. In this presentation, the project is overviewed for further understanding the goals of collaborative research team and the first screened species for marginal peatland.

Jabon (Anthocephalus cadamba) is a promosing fast growing wood species that is widely planted in community forests and industrial plantation forests but the wood has a relatively low density, durability, and mechanical properties which limited its application as structural timbers. One of the alternative utilizations of jabon wood is by converting into wood pellet for bioenergy. The aim of this study was to improve the properties of wood pellets from jabon through rapid torrefaction using Counter-Flow Multi Baffle (COMB) reactor, a pilot plant for torrefaction of biomass with a capacity of 20 kg/h that has a main advantage of performing torrefaction within a short period of time. Wood pellets were classified according to its length and then torrefied at 300°C with a residence time of 3 min. Torrefied pellets (black pellets) were succesfully produced. The initial moisture content of the long and short pellets of 12.76% and 12.47% decreased up to 2.85% and 2.61% after torrefaction. Water immersion test for 1 min, 5 min, 30 min, 1 h, 6 h, 12 h, and 24 h showed that the raw pellets (control) fully disintegrated after 30 min, while black pellets showed no significant disintegration even after 24 h test which is an advantage for long period storage of pellets. The initial calorific values of long and short pellets of 17.69 MJ/kg and 17.35 MJ/kg increased up to 31.79 MJ/kg and 32.02 MJ/kg after torrefaction. The results proposed that rapid torrefaction using COMB could provide a great improvement in bioenergetic properties of wood pellets from fast growing species as jabon wood.

In this study we have developed a modified charcoal kiln for both thermal therapy and charcoal production. The kiln design placed emphasis on safety and cleanliness including charcoal quality. The modified charcoal kiln had two entrances for charcoal production and thermal therapy. A noxious gas barrier was also installed between adjacent charcoal kilns for thermal therapy. In addition, a fine dust collector was fitted to remove fine dust generated during the charcoal production. For the verification of this kiln, harmful substances and fine dust were measured after charring process. Also we compared some characteristics of the white charcoal made from the thermal therapy kiln and traditional kiln. For evaluation of charcoal quality for both kilns, anatomical and physical characteristics, calorific value and proximate analyses such as ash contents, volatile matter, fixed carbon and pH were examined. Consequently, the results of harmful substance and fine dust in the modified charcoal kiln for thermal therapy met the reference value of Atmosphere Environment Conservation Act, Ministry of Environment, South Korea. In addition, there were no considerable differences in the properties of the white charcoal produced from both kilns.

Gekko japonicus are distributed at most regions of Japan, inland and the middle east regions of China and southern coastal cities of Korea. Although various studies have been conducted, no research was done on population genetics across the three countries. To verify the genetic diversity and population structure of G. japonicus across Korea, Japan and China, we collected total 416 geckos from thirteen populations, and obtained sequence data on mitochondrial DNA (ND2 and Cytb) and nuclear DNA (RAG-1). Overall, levels of intrapopulation genetic diversity were low, indicating moderate haplotype and low nucleotide diversity. Total 18 haplotypes appeared in mtDNA analysis. The haplotype and nucleotide diversity were 0.607±0.016, 0.00058±0.00002, respectively and for nDNA, we identified 27 haplotypes having 0.755±0.008 haplotype diversity, and 0.00516±0.00007 nucleotide diversity. In phylogenetic analyses, China had more older ancestors than Korea and Japan. Overall, our data suggest that the first introduction (or dispersal) might occur from China to Korea and Japan and the secondary introductions might occur among the three countries while occurring independent local genetic diversification in each country.

In South Korea, Gekko japonicus has been observed persistently since the first report by Stejneger in 1907. Researches on the distribution, reproduction, and food items of G. japonicus have conducted, while studies on spatial ecological niche were not executed yet. We have investigated the home range and movement pattern of G. japonicus using radio-tracking method. This study was performed for 33 days from Jun 8 to July 10, 2018 near the cable car building, toilet building and woods in Geumgang Park (N 35°13′, E 129°04′), Dongnae-gu, Busan. The 17 geckos, 9 males and 8 females, were captured and, after attaching the transmitter package, the geckos were released at the collection sites. Gekko japonicus used trees and buildings as microhabitats at a ratio of 46.6% : 53.6%. The geckos moved significantly farther distance when they were on the trees (10.0±0.8 m) than when in the buildings (4.1±0.5 m). But it was not different between sex. For about one month, the average home range of G. japonicus was MCP: 644.8 m2, Kernel 50: 128.3 m2 and Kernel 95: 916.4 m2 and the size was not different between sex. During the research period, G. japonicus used about 27 × 27 m as core ecological area and used 64 × 64 m as a home range. Our results could be helpful to further understand the microhabitat use of G. japonicus and for its effective management.

Camera trapping (CT) is one of the methods to survey wildlife. This method is used for monitoring nocturnal mammals, which cannot be seen directly, and for the use of habitats and identification of terrestrial mammals. However, there are many identification errors in results of data analysis because of no criteria in analysis of camera trapping data and lack of researcher's experience. Our purpose of this study is to make an identification index. This study used 6,746 pictures, which wildlife is included, of 27,061 pictures taken from 21 cameras installed in the Jangsudae, Seoraksan National Park during the period of May 2016 to July 2017. After production of index, the error rate was derived through the verification of expert who have experience above 5 years in the field of wildlife ecology. After the index applied, total error rate was 1.2% in detail, 2.1% in water deer and 1.8% in Roe deer. To verify usefulness of identification index, we analysis another CT data which include four species of Roe deer (Capreolus pygargus), Water deer (Hydropotes inermis), Badger (Meles meles) and Raccoon dog (Nyctereutes procyonoides which are most confusing species to identify. In additional analysis, we used 3,549 photos which wildlife is included, of 93,287 photos from 75 cameras installed in Osaek, Seoraksan National Park from November 2015 to July 2016. In the case of further analysis, average error rate was 0.3% in 4 species, and the error rates were 0% in Water deer, 1.2% in Roe deer, 0% in Raccoon dog, and 0.6% in Badger. Identification idex what we made will contribute to the study of mammals using camera trapping.

This study was conducted to investigate and to compare the anatomical characteristics among compression wood (CW), lateral wood (LW), and opposite wood (OW) in the stem wood of Ginkgo biloba. To analyze the anatomical characteristics, optical and scanning electron microscopy and an X-ray diffraction method were used. The CW showed circular tracheid with angular outline, numerous intercellular spaces, varying of lumen size, slit-like bordered pits, piceoid pits in the crossfield, and a few spiral checks. The LW and OW showed rectangular tracheid, a few intercellular spaces, varying of lumen size, bordered pit and cuppersoid pit in the crossfield. Rays were mainly uniseriate, with a few biseriate rays in tangential section of CW, LW, and OW. The CW and OW showed similar tracheid lengths in the 5th and 10th growth rings; however, the CW was the shortest in the 15th to 20th growth rings. The CW showed the highest ray height and lowest ray number in each growth ring. The MFAs of the CW were greater than those in the LW and OW from both measurement methods. The MFAs obtained from the iodine method were smaller than that of the MFAs obtained from the pit aperture measurements. The CW had the lowest relative crystallinity in each growth ring, whereas the crystal width of the CW was the smallest in the 5th and 15th to 20th growth rings. Consequently, there were some significant differences in anatomical characteristics among CW, LW, and OW in a stem of Ginkgo biloba.

In this study, we examined the effect of particle size and heat treatment on the crystal transformation of wood cellulose during alkaline swelling. We used wood flours which have different size as 40mesh, 60mesh, 100mesh, 200mesh and wood chips from Paulownia tomentosa for the samples. Control and heat-treated samples at 100℃ and 200℃ were treated with 15% NaOH solution for 10 minutes, and followed by washing with distilled water and dried at room temperature. We observed the morphology of wood samples using an optical microscope, and compared the relative crystallinity and crystal width before and after alkali -treatment and heat-treatment using an X-ray diffraction method. During alkali swelling after heat-treatment, the crystal transformation of cellulose I to cellulose II was also investigated. By alkali treatment, the color of the wood samples tended to be dark, and the alkali-treated samples shrank more than the untreated samples. The relative crystallinity of wood cellulose decreased with decreasing particle size of wood flours and slightly increased with increasing temperature, and the crystal width was not significantly different. Also, heat-treated samples were easily transformed to cellulose II structure compared to control samples.

Lignin was isolated by using an ionic liquid, known as an environmentally friendly green solvent, which is effective in isolating and purifying lignin with minimal chemical transformations and high purity. Lignocellulosic biomass is one of the most important biomass resources and has been selected as alix gracilistyla Miq. with rapid growth characteristics. Salix gracilistyla Miq. samples with extractives free were pretreated by 1-ethyl-3-methylimidazolium acetate (EminAc). The solid content of wood powder was 15%, and the reaction was carried out at 80, 90, 100 and 120 ℃ for 2 hours. The amount of water soluble fraction was about 10% at the reaction temperature of 60, 80 and 90 ℃, and more than two times at 120 ℃. The yield of lignin obtained from the water soluble fraction at 120 ℃ for 2h was about 4%. The properties of IL-pretreated lignin (purity and molecular weight) were investigated by FT-IR and GPC analysis.

In this study, a suspension of lignocellulose nanofibril (LCNF) and poly (vinyl alcohol) (PVA) was used to fabricate PVA/LCNF electrospun nanofibers through electrospinning. LCNF was prepared by alkaline-peroxide (AP) pretreatment to control lignin and hemicellulose contents, and was subjected to be fibrillated by sequential treatment with wet disk-milling (WDM) and high pressure homogenizer (HPH). The morphological characteristics of WDM and HPH treated LCNFs were investigated by field emission scanning electron microscopy (FE-SEM) and the average diameter and the filtration time were compared. The viscosity of the suspension of PVA and LCNFs treated with WDM and HPH was measured. Then, PVA/LCNF electrospun nanofiber was obtained by electrospinning. The obtained PVA/LCNF electrospun nanofiber was observed by FE-SEM and the average diameter was measured. The resulting diameter of LCNF decreased with reduction of lignin and hemicellulose content. In suspension containing PVA and untreated LCNF, the viscosity of the suspension increased and the diameter of the electrospun nanofiber increased with increasing suspension concentration or LCNF addition. The reduction of lignin and hemicellulose also increased the viscosity of the PVA/LCNF suspension and the diameter of the electrospun nanofiber.

Poly(hydroxyethyl acrylate-co-phenyl vinyl sulfide)(poly(HEA-co-PVS) was polymerized by free radical reaction. The polymerization of poly(HEA-co-PVS) was confirmed by UV spectrum and 1H NMR analysis. The amphiphilic property of poly(HEA-co-PVS) was confirmed by interfacial tension analysis. Poly(HEA-co-PVS) oxidized by H2O2 (oxidation-poly(HEA-co-PVS)) was lost amphipathicity. The lower critical solution temperature was observed by the optical density change of the poly(HEA-co-PVS) solution according to the temperature change, and the LCST of oxidation-poly(HEA-co-PVS) was increased. Poly(HEA-co-PVS) micelle was prepared by thin film method. The prepared poly(HEA-co-PVS) micelle was observed to be spherical through transmission electron microscope (TEM). The release degree of poly(HEA-co-PVS) micelle loaded nile red (fluorescent dye) was examined by temperature and oxidation stimulation. The release degree of poly(HEA-co-PVS) micelle was more dependent on temperature (above LCST) and oxidation conditions.

Monoolein (1-Oleoyl-rac-glycerol, MO) cubic phase containing poly(hydroxyethyl acrylate-co-propyl methacrylate-co-methacrylic acid) (P(HEA/PMA/MAA)) in its water channel was prepared by a melt-hydration method. P(HEA/PMA/MAA) whose HEA/PMA/MAA molar ratio was 100/2.8/0, 100/6.0/1.6, and 100/6.2/2.5 was prepared by a free radical reaction, confirmed by 1H NMR spectroscopy. Only P(HEA/PMA/MAA)(100/6.0/1.6) exhibited its lower critical solution temperature around 32.8 ℃. The air water/interfacial measurement revealed that the copolymers were surface-active. On the transmission electron microscopy photo, the copolymer had little effect on the structure of the cubic phase. On the differential scanning calorimetry thermogram, MO cubic phase without the copolymer exhibited its phase transition temperature (PTT) around 68.1 ℃ and the inclusion of copolymer in the cubic phase caused the PTT to decrease by 3 to 4 ℃. The effect on the electric field promoted amaranth (dye) emission on the cubic phase. Release by the electric field was further enhanced in copolymers with a high ratio of MAA.

H2O2-triggerable liposomes were prepared by modifying the liposome surface with an H2O2-responsive polymer. DOPE liposomes can be formed by incorporating amphiphilic polymer. The polymer was synthesized by a free radical reaction. Polymerization was confirmed by 1H-NMR, and FT-IR. The degree of surface activity of the polymers was also examined. As a result of the polymer characterization, the polymer was measured amphiphilic. Liposomes were prepared by varying the content of the polymer. The quenching degree of the liposome was confirmed to be about 46.2% to 57.7%. Liposome morphology was observed with a TEM microscope. As the weight ratio of polymer to DOPE lipid increased, the average diameter of liposome increased and triggerable release of calcein. When H2O2 concentration was 0%, 1.5%, 3.0%, and 6.0%, the DOPE to polymer ratio of 200:1 liposome release about 0.5%, 50.8%, 78.0%, and 78.4%, respectively. DOPE liposome with polymer 200:4 was more susceptible to H2O2 and showed 80% release within 20 seconds.

Kluyveromyces marxianus is well known thermotolerant yeast capable of growing at high temperature (45oC). However ethanol production is very inefficient from xylose which is second major sugar when cellulosic biomass is broken down enzymatically. Directed evolutionary approach and random mutagenesis were performed on K. marxianus KCTC17694 for isolating the mutant strain producing ethanol from xylose efficiently. The isolated mutant strain, K. marxianus 17694-DH1, exhibited 3.90 fold and 2.31 fold improvement in ethanol concentration and ethanol production yield from xylose, respectively as compared to the parental strain. When enzymatic assays of xylitol dehydrogenase (XDH) from the parental strain and K. marxianus 17694-DH1 were performed, XDH activities were significantly improved (28.1~64.8%) in the mutant strain up to 50°C of reaction temperatures. Under optimum conditions on bioreactor, xylose consumption rate and ethanol production rate were 0.66 g/L∙h and 0.14 g/L∙h, respectively which were 2.15 fold and 1.82 fold improvement, respectively as compared to those from the flask cultures.

Due to the depletion of fossil fuels, cellulosic biomass has been focused on as an attractive resource. Cellulosic biomass, mainly composed of cellulose and hemicellulose, is enzymatically hydrolyzed to glucose and xylose, respectively. Therefore, it is necessary to develop the strain capable of utilizing both glucose and xylose efficiently for biofuel productions. However, glucose and xylose are consumed sequentially because of catabolite repression by glucose, which cause inefficient utilization of cellulosic biomass. In this study, we performed a directed evolutionary approach using 2-deoxyglucose, the analogue of glucose, to isolate the mutant K. marxianus SBK1 capable of cofermenting glucose and xylose simultaneously. K. marxianus SBK1 exibited improved xylose consumption rate (163%), ethanol yield (19%), and ethanol productivity (67%) as compared to the parental strain. Cofermentations were performed with various concentrations of glucose and 40 g/L of xylose to investigate the effect of catabolite repression by glucose. When the glucose concentrations were increased, the xylose consumption rates decreased gradually. It suggests that K. marxianus SBK1 still showed catabolite repression at high concentrations of glucose although catabolite repression was highly alleviated at low concentrations of glucose.

Due to increased environmental concerns and needs for energy security, biofuel productions have become attractive alternatives to the fossil fuels. The production of biofuels from edible starch were suffer from ethical problems of using food resources. Biofuels production using non-edible cellulosic biomass has been attempted to solve those problems. Xylose, one of the main components of cellulosic biomass, can be converted to xylitol which has been known as a valuable synthetic building block. In this study, K. marxianus KCTC17555ΔURA3 strain was engineered by multi-copy random integration of the mutant KmXYL1 (mKmXYL1) gene from K. marxianus 36907-FMEL1. When fermentation experiments were performed using xylose as a sole carbon source at 40°C, K. marxianus 17555-JBP2 produced 53.17 g·L-1 of xylitol with 0.73 g·g-1 yield and 0.55 g·L-1·h-1 productivity. In conclusion, K. marxianus 17555-JBP2 showed 190% and 300% improvement of xylose consumption rate and xylitol production rates, respectively.

Catechin belonging to the tannins are found in various kinds of tea, and are mainly contained in green tea. It has a strong reducing effect and have antioxidant, antiviral, antibacterial effect as well. In addition, derivatives produced from catechin degradation are known as high value-added substances. Previously, we isolated two bacteria capable of degrading catechin from soil. These two bacteria were identified as Enterobacter sp. Several genes were cloned to identify catechin degrading enzymes from two isolated bacteria. Using cloned genes, catechin degrading enzyme overexpression systems were constructed with pET-21a vector. As results of overexpression using a recombinant E. coli, a soluble from enzyme was overexpressed. This enzyme exhibited catechin degradation activity after purification using 6His tag.

Lignin is the second most abundant natural polymers and sustainable resource obtained as a co-product from either the pulping industry or the bioethanol production using the lignocellusic biomass. There are various pretreament processes using lignocellulosic biomass, among which kraft and sulfite pulping are the dominant processes to obtain lignin as a co-product. However, lignin has significantly different physical and chemical properties depending on the pretreatment process. Therefore, for the efficient utilization of lignin, characteristics of lignin must be clearly analyzed. In this study, four extracted lignins from different resources, hardwood kraft lignin (L1), hardwood supercritical water oxidation lignin (L2), silver grass steam-explosion lignin (L3), and commercial lignin (L4), were subjected to several analyses to characterize their thermal as well as chemical structural properties. L1 revealed relatively low value of 1430 g/mol (Mn) and 4.0 (PDI) but the remaining three lignins showed similar molecular weights. The methoxyl group contents of four lignins L1 to L4 were 4.0 mmol/g, 3.1 mmol/g, 0.8 mmol/g, and 1.6 mmol/g, respectively. As results of DFRC analysis, L4 was found to have only quaiacyl type lignin, confirmed to be extracted from softwood. The FT-IR spectra of four lignins were very similar. Additional chemical structures of lignins such as phenolic hydroxyl and aliphatic hydroxyl content were investigated by 1H NMR. Moreover, TGA/DSC was conducted to analyze thermal stabilities and degradation behavior of the lignins.

In bone tissue engineering, the scaffolds requires have excellent biocompatibility, proper mechanical and osteo-inductive properties. Cellulose nanocrystals (CNCs) have emerged as promising candidates for producing micro/nano-platforms that could be replaced tissues more efficiently. CNCs, a sustainable and abundant biopolymer, are generally presented in the cell walls of various nature resources. CNCs offer interesting properties for composites because they can impart improved mechanical, chemical, and thermal properties and they are biodegradable. Rice husks as a resource of cellulose to obtain nanocrystals by acid hydrolysis have been used. Thereafter, cell culture studies (using hMSC) were performed to determine the effect of CNCs on cell proliferation and differentiation. The in vitro influences of CNCs derived from rice husk have been demonstrated (like efficient cell adhesion, proliferation and differentiation) and have provided initial consequence to support subsequent studies.

In the emerging tissue engineering applications, porous scaffolds are used to support bone tissue cells to replace and complement the current approach of organ transplantation. The cornerstone of successful tissue engineering applications depends on two essential elements of cells and scaffolds, and the suitable design of a platform for three-dimensional (3D) scaffolding is determining both biomaterials and manufacturing protocols via detailed and exact mechanical and biological needs like biocompatibility, porosity, biodegradability, surface characteristics, and so forth. Recent carbon-nanomaterials have emerged as promising candidates for producing scaffolds that can replace tissues more efficiently. Importantly, carbon-nanomaterials (CNMs) offer interesting properties for biological applications due to their very high aspect ratio, combined with outstanding mechanical and electrical properties. In addition, the advantages of carbon nanomaterials on stem cells (such as efficient attachment, proliferation and differentiation) have been demonstrated in vivo and have provided initial consequence to support subsequent studies. In this work, a new three-dimensional (3D) printing system based on for fused deposition modeling (FDM) is developed for the fabrication of 3D nanocomposite-based microstructures. The results of our study suggest improved mechanical and biological properties of the 3D platform, and provide a high potential for application of nanomaterial scaffolds in a wide range of tissues.

Over-expression of reactive oxygen species (ROS) in the tissues lead to diabetic complications such as cardiac dysfunction, diabetic nephropathy and endothelial dysfunction. Pharmaceutical agents are required for the treatment and prevent of these complications. Quercetin is a polyphenol flavonoid, which is widely found in vegetables, grains and fruits, and is known for its antioxidant activity against oxidative stress. In this study, we determined that quercetin protected H9c2 cells against oxidative stress. To induce ROS in the cell, H9c2 cells were exposed to hydrogen peroxide (H2O2), hyperglycemia and sodium arsenite (NaAsO2). These materials were decreased the cell viability of H9c2 cells by oxidative stress induced time and concentration dependent. Quercetin strongly protected H9c2 cells under the stressful conditions by reducing intracellular ROS level and inhibiting apoptosis pathway. Quercetin may be useful therapeutic component for the treatment or prevention of myocardial infarction.