• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.4
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• pp.32-42
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• 2012

Wood biomass including forest residues, waste wood, and construction residuals has been widely generated in Korea, but forest biomass from the National Forest Management Operation Project plays a big role in generating wood biomass. Unfortunately the promotion policy of woody energy organized by the Forest Service in Korea concentrates more on demand creation rather than on supply expansion. Therefore, in order to utilize insufficient wood resources effectively, it is greatly required to develop uses for maximizing their added value. In particular, more attention to the use of the second generation biomass has been paid in foreign countries because there is a threshold that the first generation biomass cannot produce enough biofuel without threatening food supplies and biodiversity. In Korea, wood pellets are regarded as the alternative clean fuels to oils and coals that emit green house gases into the atmosphere. However, using wood as pellet raw materials can not be an economic way because the value of wood disappears right after burning in the boiler in spite of its contribution to the decrease of carbon emission. Differently from wood pellets, kraft pulping process using woody biomass produces black liquor as a by-product which can be used to generate electricity, bioenergy and biochemicals through gasification. Thus, it can be more economical to make a torrefaction of lignocellulosic biomass such as low-quality wood and agricultural leftovers as raw materials of pellets.

• Korean Journal of Microbiology
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• v.54 no.3
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• pp.299-301
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• 2018

Microbulbifer agarilyticus GP101 was isolated from the gut of a marine invertebrate Turbo cornutus and capable of degrading polysaccharide such as agar, alginate, and ${\kappa}$-carrageenan constituting algal cell wall. To obtain genomic basis of polysaccharide-degrading activity, we sequenced genome of strain GP101. The genome consists of 4,255,625 bp, 3,458 coding sequences with 55.4% G + C contents. BLASTP search revealed the presence of seven agarases, five alginate lyases, ten glucanases, four chitinases, two xylanases, one ${\kappa}$-carrageenase, and one laminarinase. The genomic data of strain GP101 will provide potential uses in the bioconversion process of diverse polysaccharide into bioenergy and biochemicals.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.10
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• pp.1548-1557
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• 2019

Objective: To investigate the effects of dietary supplementation with different levels and molecular weights of fungal ${\beta}$-glucan on productive performances, health, carcass traits and meat quality in broilers. Methods: Two hundred and ten of one-day-old chicks with equal sex were assigned to seven experimental groups in $2{\times}4$ factorial arrangement. These groups were supplemented with (0, 10, 30, and 60 ppm) of molecular weight 1-3, 1-6 ${\beta}$-glucan (low or high). High molecular weight ${\beta}$-glucan (H: 943 kDa) was obtained from Ophiocordyceps dipterigena BCC 2073, whereas H with ${\gamma}$-Irradiation treatment was performed to achieve low molecular weight ${\beta}$-glucan (L: 8 kDa). Results: There was no statistical significance in productive performances, apparent digestibility and interaction between fixed factors along 42 days of experiment (p>0.05). A higher caecal amylase activity was present in the group that received L, while there was a dramatic decrease in H and the control groups, respectively (p<0.05). The increase of supplemental dose increased caecal amylase activity (p<0.05). Immunomodulatory effects from L was revealed by the marked increase of phagocytic activity, relative weight of thymus and bursa of fabricius (p<0.05). Similarly, the additive dose at 30 ppm provided the same results, whereas the only significant difference with supplementation at 60 ppm was an increase in phagocytic activity (p<0.05). Interestingly, villi height of broilers fed L was higher than other groups (p<0.05). The treatments did not influence haematology, blood chemistry, antibody production level against vaccination, carcass traits and meat quality (p>0.05). Conclusion: The supplementation of L at 30 ppm was suggested to achieve benefits of immune modulation without adverse effects on other parameters.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.74-74
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• 2002

Production of u 1-antitrypsin ($\alpha$AT) in transgenic cows has a great value in the field of medicine. The present study was conducted to determine the effect of chemically defined KSOM media on in vitro development of bovine transgenic nuclear transfer (NT) embryos. An expression plasmid for human $\alpha$AT was constructed by inserting a bovine beta-casein promoter, a green fluorescent protein (GFP) marker gene, and a human $\alpha$AT target gene into a pcDNA3 plasmid. Cumulus cells as donor nuclei in NT were collected from a Holstein cow and transfected by lipid-mediated method using FuGene6 (Roche Molecular Biochemicals, USA) as reagent. GFP expressed cumulus cells were introduced into recipient oocytes under DIC microscopy equipped with FITC filter set. After electrical fusion and chemical activation, reconstructed embryos were cultured in 1) SOF + 0.8% BSA, 2) KSOM + 0.8% BSA, 3) KSOM + 10% FBS and 4) KSOM +0.01% PVA for 192 h at 39$^{\circ}C$ with 5% $CO_2$, 5% $O_2$ and 90% $N_2$in humidified condition. The development of the embryos was recorded and the GFP expression in blastocyst was determined under FITC filter. The average fusion rate was 73.8% (251/340; n=8). The development rates to 2-4 cells, morula, blastocysts and expression rates in blastocysts varied from 70.3 to 76.5%, 30.2 to 33.8%, 25.4 to 33.8% and 11.8 to 15.6%, respectively. The difference in development and expression rates of embryos among 4 culture groups was not significant (P>0.05). This study indicates that chemically defined KSOM medium is also able to support development of bovine transgenic NT embryos at similar rate of SOF or KSOM supplemented with BSA or serum.

• Journal of Microbiology and Biotechnology
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• v.33 no.1
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• pp.1-14
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• 2023

Polyethylene terephthalate (PET) is a plastic material commonly applied to beverage packaging used in everyday life. Owing to PET's versatility and ease of use, its consumption has continuously increased, resulting in considerable waste generation. Several physical and chemical recycling processes have been developed to address this problem. Recently, biological upcycling is being actively studied and has come to be regarded as a powerful technology for overcoming the economic issues associated with conventional recycling methods. For upcycling, PET should be degraded into small molecules, such as terephthalic acid and ethylene glycol, which are utilized as substrates for bioconversion, through various degradation processes, including gasification, pyrolysis, and chemical/biological depolymerization. Furthermore, biological upcycling methods have been applied to biosynthesize value-added chemicals, such as adipic acid, muconic acid, catechol, vanillin, and glycolic acid. In this review, we introduce and discuss various degradation methods that yield substrates for bioconversion and biological upcycling processes to produce value-added biochemicals. These technologies encourage a circular economy, which reduces the amount of waste released into the environment.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.73-73
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• 2022

Lettuce (Lactuca sativa L., Family Asteraceae) is highly ranked in production and economic value and is consumed either fresh or in salad mixes because of its important dietary source of bioactive phytochemicals. The world collection of Lactuca spp. leafy crops, maintained in NAC, includes 2,464 accessions from 71 countries around the world, of which 2,411 belong to L. sativa species, nineteen to L. saligna, and fifteen to L. serriolar. We aimed to investigate the lettuce germplasm with morphological and biochemical analyses and provide new material for breeding. The lettuce crop comprises seven main groups of cultivars (including oilseed lettuce) differing phenotypically. Agricultural characteristcs were investigated including time to bolting, time to flowering, seed color, flower color, leaf attitude, leaf color, leaf anthocyanin coloration, type of incision of margin, depth of incisions of margins, and leaf venation. Screening of the health beneficial metabolites like anthocyanin and bitter sesquiterpene lactones (lactucin and lactucopicrin) was also conducted. The range of anthocyanin and SLs were 0~563.78 mg/100g D.W. and 3.74~3311.66 ug/g D.W., respectively. The investigation of the degree of variation regarding phenotypic traits and biochemical revealed adaptive stable and highly variable use of trait collection.

• Korean Chemical Engineering Research
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• v.55 no.5
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• pp.609-617
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• 2017

Lignocellulosic biomass is a renewable resource for production of biofuels and biochemicals. Furfural (FF) is an important platform chemical catalytically derived from the hemicellulose fraction of biomass. Tetrahydrofurfuryl alcohol (THFA) is a FF derivative and can be used as an eco-friendly solvent with thermal and chemical stability. Despite large numbers of experimental studies for catalytic conversion of FF to THFA, few research have conducted on the economic feasibility for large-scale THFA production from FF. At the stage of assessment of the potential for commercialization of conversion technology, a large-scale process study is required to identify technological bottleneck and to obtain information for solving scale-up problems. In this study, process simulation and technoeconomic evaluation for catalytic conversion of FF to THFA are performed, as the following three steps: integrated process design, heat integration, and economic evaluation. First, a large-scale process including conversion and separation processes is designed based on experimental results. When the FF processing rate is 255 tonnes per day, the FF-to-THFA yields are 63.2~67.9 mol%. After heat integration, the heating requirements are reduced by 14.4~16.4%. Finally, we analyze the cost drivers and calculate minimum selling price of THFA by economic evaluation. The minimum selling price of THFA for the developed process are $2,120~2,340 per tonne, which are close to the current THFA market price.

• Korean Journal of Environmental Agriculture
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• v.14 no.1
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• pp.82-87
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• 1995

The standardization of test procedures and reproducibility of the toxicity data are prerequisite for the toxicity testing with the earthworm culturing in the laboratory. No in-depth study on culturing conditions of earthworms has been conducted in Korea, even of massive cultural practice is common for composting and production of biochemicals. The earthworms, Lumbricus rubellus and Eisenia foetida, were cultured in three kinds of artificial soil substrates(I, II and III) based on the OECD Guideline, which consist of different ratios of components (sand, sphagnum peat and kaolinite), and fed with a mixture of grain powders. During the period of culturing, the body weight and reproduction parameters were measured. L. rubellus showed the best results for increasing body weight and cocoon production in the artificial soil substrate(I) compared with E. foetida. The cocoon production was significantly high in both species cultured in the artificial soil substrate(I) among the three kinds of soil substrates, but the cumulative cocoon production of L. rubellus was 11 cocoon per worm compared with 3.7 cocoons per worm of E.foetida. L. rubellus, therefore, was more prolific than E. foetida in these culture schemes. The cumulative mortality in both species was less than 10%, and the number of juvenile worms per cocoon ranged from 1.5 to 2.3 and thus did not show any relationships with soil substrates or species. From these data, the culture of L. rubellus in the laboratory could be standardized, but for E. foetida, further study would be necessary to establish the optimal growth conditions in the laboratory.

• Journal of Life Science
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• v.23 no.7
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• pp.863-868
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• 2013

The XylP gene, which encodes endoxylanase in Bacillus sp. HY-20, was subcloned, and two expression plasmids, pG-xylP and pGMF-xylP were constructed. These plasmids, which contain different signal sequences, XylP s.s and $MF{\alpha}_{opt}$ s.s, respectively, for the secretory expression of endoxylanase, were transformed into Saccharomyces cerevisiae SEY2102 and FY833, respectively. The recombinant endoxylanases were successfully expressed, with a total activity range of 23.7-70.1 unit/ml according to the expression system and host strain. The endoxylanase activity in SEY2102/pGMF-xylP reached a maximum of 88.1 unit/ml in baffled flask culture. Most of the recombinant endoxylanase was efficiently secreted in the extracellular fraction, and the $MF{\alpha}_{opt}$ s.s was more efficient for secreting endoxylanase in yeast than the XylP s.s. Therefore, the expression system developed in this study produces large extracellular amounts of endoxylanase using S. cerevisiae as the host strain, and it could be used in bioethanol production and industrial applications.

• Molecules and Cells
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• v.19 no.1
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• pp.137-142
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• 2005

We showed recently that ginsenosides inhibit the activity of various types of ion channel. Here we have investigated the role of the carbohydrate component of ginsenoside $Rg_3$ in the inhibition of $Na^+$ channels. The channels were expressed in Xenopus oocytes by injecting cRNAs encoding rat brain Nav1.2 ${\alpha}$ and ${\beta}1$ subunits, and analyzed by the two-electrode voltage clamp technique. Treatment with $Rg_3$ reversibly inhibited the inward $Na^+$ peak current ($I_{Na}$) with an $IC_{50}$ of $32.2{\pm}4.5{\mu}M$, and the inhibition was voltage-dependent. To examine the role of the sugar moiety, we prepared a straight chain form of the second glucose and a conjugate of this glucose with 3-(4-hydroxyphenyl) propionic acid hydrazide (HPPH). Neither derivative inhibited $I_{Na}$. Treatment with the carbohydrate portion of ginsenoside $Rg_3$, sophorose [${\beta}-D-glucopyranosyl$ ($1{\rightarrow}2$)-${\beta}-glucopyranoside$], or the aglycone (protopanaxadiol), on their own or in combination had no effect on $I_{Na}$. These observations indicate that the carbohydrate portion of ginsenoside $Rg_3$ plays an important role in its effect on the $Na^+$ channel.