• KSBB Journal
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• v.10 no.5
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• pp.589-597
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• 1995

Protein-bound polysaccahrides(PBP) were isolated, purified, and characterized from the sawdust media after harvesting the fruit body of Flammulina velutipes. The yield of the crude PBP(Fr.CA) extracted from the sawdust media, was 0.367% relative to the original sawdust media. The total sugar and protein contents of Fr.CA were 19.8% and 23.8% respectively. Using the membrane filtration, the fraction of which the molecular weight is over 300 kDa(Fr.A) was isolated from the Fr.CA and the yield was 44.6% relative to the Fr.CA. This result indicates that high molecular PBP is the dominant components of the Fr.CA. The Fr.A was separated into three fractions (Fr.A-1, Fr.A-2 and Fr.A-3) whose yields are 5.8%, 8.5% and 13.2% respectively. These fractions were further purified using gel filtration, obtaining a single peak in each fraction that considered as pure PBP Among them, the yield of Fr.A-1-${\alpha}$ was 20.9% relative to the Fr.A-1, and the molecular weight was 800 kDa. Monosaccharide components such as glucose, galactose, mannose, xylose and fucose could be detected all fractions by a HPLC analysis. Especially in the Fr.A-1-${\alpha}$ fraction, the content of glucose and galactose appeared to be high.

• Korean Journal of Food Science and Technology
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• v.40 no.2
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• pp.220-227
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• 2008

In this study, polysaccharides were isolated from Korean persimmon vinegar to characterize the polysaccharides existing as soluble forms within traditional Korean fermented beverages, and their immuno-stimulating activities were examined. Three successive chromatographies were used to purify the main polysaccharide in the persimmon vinegar, PV-1b-I, to homogeneity from the crude polysaccharide (PV-0). The molecular mass of PV-1b-I was estimated as 110 kDa and it contained significant proportions of mannose (46.8%), galactose (28.5%) and arabinose (19.1%). PV-1b-I strongly reacted with ${\beta}$-glucosyl Yariv reagent, suggesting the presence of an arabino-3,6-galactan moiety. PV-1b-I also induced high levels of macrophage activation and mitogenicity on murine splenocytes in vitro. The intravenous administration of PV-1b-I significantly augmented NK cytotoxicity against YAC-1 tumor cells. PV-1b-I also showed potent anticomplementary activity in a dose-dependent manner. Finally, C3 activation products were identified by crossed immunoelectrophoresis using anti-human C3 and the anti-complementary activity of PV-1b-I under $Ca^{2+}$-free conditions, suggesting that this PV-1b-I causes complementary activations via both alternative and classical pathways. From these results, one can conclude that Korean persimmon vinegar contains select polysaccharides in addition to healthy components, and these polysaccharides appear to provide immuno-stimulating activities beneficial to human health.

• Korean Journal of Food Science and Technology
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• v.51 no.4
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• pp.336-342
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• 2019

To elucidate structure-function relationship of polysaccharide from Angelica gigas, the AGE-2c-I was purified by two successive chromatography steps. AGE-2c-I showed a potent anti-complementary activity in a dose-dependent manner. AGE-2c-I with a molecular weight of 140 kDa comprised four monosaccharides and 13 glycosyl linkages, and strongly reacted with ${\beta}$-glucosyl Yariv reagent. For the fine structure analysis of AGE-2c-I, it was sequentially digested by exo-arabinofuranosidase and endo-galactanase. The results indicated that AGE-2c-I was a typical RG-I polysaccharide with side chains such as highly branched ${\alpha}$-arabinan, ${\beta}$-($1{\rightarrow}4$)-galactan and arabino-${\beta}$-3,6-galactan. To characterize the active moiety of AGE-2c-I, the anti-complementary activities of AGE-2c-I and its subfractions were assayed. It was observed that the anti-complementary activity of AGE-2c-I was due to the entire structure that resembled RG-I. In addition, arabino-${\beta}$-3,6-galactan side chain (GN-I) in AGE-2c-I probably plays a crucial role in the anti-complementary activity, whereas ${\alpha}$-arabinan side chain (AFN-I) consisting of 5-linked Araf and 3,5-branched Araf partially contributes to the activity.

• Food Science and Industry
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• v.53 no.1
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• pp.69-83
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• 2020

For the development of the chitosan industry in Korea, the catch of red snow crabs caught on the east coast is rapidly decreasing. Therefore, it is urgent to develop raw materials that can replace the red snow crab as the top priority to solve the supply and demand problems, as well as wastewater treatment costs account for a large proportion of the cost of chitosan. In order to solve the problems, continuous research on biological extraction methods such as enzymatic extraction and microbial fermentation will increase production efficiency and lower unit cost as well as chemical extraction methods. Further efficient manufacturing method can be established. Establishing of novel techniques is indispensable for production of high-purity chitosan and the ability to regulate and separate the molecular weight, as well as joint research with industry, academia and research institute for the research and development of high-functional chitosan derivatives.

• Journal of Korean Society of Water and Wastewater
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• v.35 no.6
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• pp.405-415
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• 2021

MMBR system has been suggested as a promising system to resolve harvesting problems induced from low settling efficiency of microalgae. And recently, a lot of research on reducing fouling at the MMBR system has investigated focused on EPS in many cases. EPS of microalgae mainly consists of polysaccharides and protein components, and is produced through photosynthesis and nitrogen-carbon metabolic pathways. Especially, P-EPS is one of major compounds which occur membrane fouling phenomenon, as its hydrophobic protein components cause floc formation and cake layer accumulation. And it is already known that almost every microalgae can metabolize P-EPS or Chl-a when nitrogen sources as a substrate is insufficient or exhausted situation. With the above backgrounds, uptake rates of P-EPS or Chl-a by Scenedesmus quadricauda according to the type of carbon source and nitrogen concentration were evaluated in order to verify correlation between carbon source vs P-EPS production, and indeed Scenedesmus quadricauda uses P-EPS or Chl-a when the amounts of nitrogen sourc es in the feed is not satisfied. As a result, it was shown that P-EPS and Chl-a production were increased proportional to nitrogen concentration under organic carbon condition. And especially, the amo unts of P-EPS and Chl-a in the cell were diminished with the nitrogen source becomes insufficient or exhausted. Because P-EPS accelerates fouling at the MMBR system, P-EPS degradation by Scenedesmus quadricauda in order to get nitrogen source may contribute to reducing fouling. About a affects of N-consumed Chl-a to the MMBR fouling, more survey is needed. On the contrary, considering the purpose of MMBR system of this study, i.e. harvesting useful high value microalgae efficiently feeding adequate industrial process wastewater, it seems like difficult to maintain satisfied metabolic activity and to harvest with high yield rate using nitrogen-poor MMBR feed.

• Composites Research
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• v.19 no.5
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• pp.7-11
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• 2006

The improved SWNTs/PANi composite actuator films applicable to an artificial muscle were fabricated successfully using a new process of manufacture that consists of 90% pure single-walled carbon nanotubes (SWNT) and chemical polymerization. PANi is electrically conducting polyaniline polymer. The conductivities of the composite SWNTs/PANi film-type actuators and the pure PANi films fabricated were measured as 56.15 S/cm and 17.38 S/cm, respectively, by the 4-prove method. The conductivity of the composite actuator is 3.2 times higher than the pure PANi film. The fabricated composite actuator showed higher conductivity than any other similar ones. The quality of samples was investigated by an electron scanning microscope (SEM). To measure the actuating strains, a specially designed beam balance apparatus was developed and strains of the composite actuators was measured by a laser displacement sensor subjected to electric currents. During the operation, the sample was soaked in the $NaNO_3$ solution and the sine-wave voltage in the range of $+1V{\sim}-1V$ was applied. The length of the composite actuator changed from $l_0=12.690$ mm to $l_1=12.733$ so that the change of length was l=0.043 mm and the strain was 0.34 %. This is a very high strain for this kind of a composite actuator. Other result reported by Tahhan showed 0.23 % strain, so that the present result is improved by 48%.

• Journal of Advanced Technology Convergence
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• v.3 no.2
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• pp.25-31
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• 2024

In recent industrialization and development due to information and communication technology, modern women in modern society are exposed to physical and mental health due to numerous stresses. Popular inflammations are attributable to a decrease in lactic acid bacteria, frequent antibiotic use, and a decrease in immunity. It is necessary to develop products that are helpful and reflected. The inner care gel currently introduced on the market can increase beneficial bacteria and maintain a healthy y-zone. The inner gel contains a hydrogel component. 90% is made up of water, and other components act as support for supporting water and are formed through crosslinking between polymer chains. Hydroxyethyl cellulose (HEC) is a hydroxyethyl ethylenetel of cellulose. The purpose of use is to act as a binder, an emulsion stabilizer, a viscosity enhancer (water-soluble), and a film forming agent. CA (crosslinker) is a crosslinking agent and serves to bind. Hydrogel in the beauty field acts as a film forming agent that gently wraps around the skin by forming a thin film and serves as an emulsion stabilizer that helps to prevent separation of other raw materials. It also acts as a thickener by increasing viscosity in cosmetics. In addition, it is used for glucose monitoring, nursing care, cell transplantation, and wound treatment in the bio field. Currently, it is understood that no products using functional hydrogel have been released, so in this study, a Y zone care hydrogel solution was manufactured to find out the antibacterial properties of the functional hydrogel, and a new solution was developed. As a result, it was confirmed that the appropriate Ph was applied to the Y zone, and after culturing Candida albicans in PDB medium, all three products of the Y zone care hydrogel solution showed an antibacterial effect of 0.5-1.0mm

• Clean Technology
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• v.30 no.1
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• pp.1-12
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• 2024

Nanoplastics (NP) exhibit distinct material properties compared to microplastics (MP), necessitating their separate recognition. Review of research outcomes and policy documents on NP reveals that most policy frameworks predominantly define MPs as solid synthetic polymer materials measuring 5 mm or less, but do not distinguish them from NP. However, recent revisions in regulations by the EU classify NPs as particles that range in size from 1 to 1,000 nm, as confirmed by some academic studies. Research on NPs often relies on experimental investigations centered around water systems, with a focus on high-concentration experimental conditions using spherical polystyrene-based NPs in behavior and impact studies. Notably, the environmental behavior characteristics of NP show differences in influence depending on the NP type, emphasizing the need for field simulation research. These challenges are mirrored in Korean society, so it is necessary to redefine NP to be distinct from MP in both research and policy. This study aimed to assess the current state of NP management globally and domestically and highlight policy considerations and issues in the existing response to NP. Upon comprehensive review, it becomes apparent that reaching an international agreement on MP faces methodological limitations, which could potentially burden efforts to precisely define NP size. Therefore, referencing the EU's recent regulatory revisions is crucial in domestic policy. Specific adjustments should commence from the MP concept through insights from the domestic industry, guidance from the academic community, and thorough discussions to ensure social acceptance.

• Journal of Life Science
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• v.26 no.5
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• pp.545-554
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• 2016

Hyaluronic acid (HA) is an important macromolecule in medical and pharmaceutical fields. HA is a natural and linear polymer composed of repeating disaccharide units of β-1, 3-N-acetyl glucosamine and β-1, 4-glucuronic acid. This work aimed to confirm the structural characteristics and anti-inflammatory activities of HA and its chemically sulfated-HA. HA was produced from a fed-batch fermentation process using Streptococcus dysgalactiae in a 5 l bioreactor. HA was isolated water-soluble form (HA-WS) and water-insoluble form (HA-WI) from culture medium, and was obtained chemically sulfated-derivative (S-HA) that resulted in a 90% yield from HA-WI. The structural features of the sulfated- HA (S-HA) were investigated by FT-IR and ¹H-NMR spectroscopy. The FT-IR and NMR patterns revealed the similarity in both the FTIR spectrum as well as NMR spectrum of both reference standard and purified HA from S. dysgalactiae. The anti-inflammatory activities of HA and S-HA were examined on LPS-induced RAW 264.7 cells. S-HA was significantly inhibited production of pro-inflammatory mediators such as nitric oxide (NO) and PGE₂ and the gene levels of iNOS and COX-2, which are responsible for the production of NO and PGE₂, respectively. Furthermore, S-HA also suppressed the overproduction of pro-inflammatory cytokine TNF-α (<80 pg/ml) and IL-6 (<100 pg/ml) compared to that of HA-WI. The present study clearly demonstrates that HA-S exhibits anti-inflammatory activities in RAW 264.7 macrophage cells.

• Korean Journal of Ecology and Environment
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• v.33 no.4 s.92
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• pp.366-373
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• 2000

Toxin production and low digestibility of cyanobacteria are known to cause low exploitability of cyanobacteria by zooplankton. In this study, we compared relative tolerance and compatibility of zooplankton taxa in eight eutrophic lakes, exposed to frequent cyanobacterial blooms, uring the summer season of 1999. Microcystis, Anabaena, Oscillatoria and Phormidium were common cyanobacteria in all lakes. with relatively lower $NO_3-N$ concentration (<0.2 mgN/l) and TN/TP ratio (<20), compared with other lakes where colonial cyanobacteria dominated. Rotifers were dominant zooplankton in most lakes, and among them, Keratella, Polyarthra and Hexathra were common. The laboratory feeding experiment showed that relative copepods that greatly decreased (90%) after 4 day when cyanobacteria were used as the food source of zooplankton, while rotifers gradually increased with the change of dominant taxa from Keratella through Pompholyx to Monostyla. These results suggest that rotifers may be capable of coexisting with cyanobacteria by exploiting them for the food source.