• The Korean Journal of Mycology
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• v.27 no.5 s.92
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• pp.322-327
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• 1999

Five white fruitbodies of Ganoderma lucidum found from two different mushroom farms, and the characteristics of atypical fruiting structure formation of these strains were described. The white fruitbodies were spontaneously generated on Quercus-log during the cultivation. They did not differentiate to the normal fruitbodies with pileus, hymenium, stipe and coloration, and fruitbodies remained non-laccateed even after 3 months. Dikaryotic mycelia isolated from the five white fruitbodies differed from wild-type strains in the mycelial growth rate, colony color, and the capacity of atypical fruiting structure (AFS) formation on agar media. These white mutants readily induced brown colored AFSs on the colonies under ventilation and illumination conditions. Both isolates Gl-010 and Gl-011 that were obtained from a normal and white fruitbody, respectively, did not form AFSs in the dark and/or under black light blue (BLB) light illumination, but induced under the visible light. They required dim light for the AFS formation, and the AFS formation was inhibited up to $0.5{\mu}mol\;m^{-2}\;S^{-1}$ in light intensity. However, the other four isolates induced AFSs even in the dark and BLB illumination, although their parent strain, isolate Gl-030, did not form AFSs under any light conditions. The monokaryotic mycelia derived from basidiospores of the AFSs of the white mutants were compatible with the original culture (dikaryon) on a dual culture.

• Korean Journal of Microbiology
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• v.1 no.1
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• pp.38-44
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• 1963

According to the experiment on pure-isolation and the related contaminants of Chlorella, the phenomena of the ecological distributions of Chlorella in Korea have been manifested in several areas and also the aim that in going to do culture, biological and physiological study of Chlorella is carried out. Contaminants very oftenly occupied on the colony of the strains taken in order to fulfil pure-isolation of Chlorella, but in accordance with being piled up the minute research on this subject, I can obtain the desirable results as follows: 1. For the pure-isolation, the duration chose the time from May to September 1957 so that may easily isolate from contaminant water with utilizing the antibiotic substances. 2. To take long time, 36-48 hours until growth of nascent through the non-sporulated, it originates from the difference of the cultured media. In addition to the above mention, the mechanism of growth until nascent through the sporulated must not always require the ligh. However the supply of metabolic energy depend upon its nutritional conditions per phase. 3. The culture of Chlorella should be based on the lower culturing except adding especial conditions such as reagent concentration of media, artifical shake of media and other facts due to the natural conditions. And also these strains grew not only in distilled water but 2% NaCl solution without any abnormality in cell it self. I, therefore, guess it is possible to culture in sea-water under phasic environment. 4. In the experiment of ammonia detection, it is caused by the sampling surroundings to contain the minute quantity of ammonia in strain No. M 918; that is the place to be plenty of Carbohydrate on behalf of protein. 5. To compare the absorption curve of chlorophyll of higher plant with that of Chlorella, the absorption zone made mostly the Same ones each other but a little absorption grade dose not clearly appear. The colony which formed giant type grows with intensive colour and green band on surrounding of the colony and after that it was changed into all the green colour and developed up to end. 6. At first phase for a week, the development of Chlorella suspends the normal condition as in vivo but after a few days, the colour of chlorophyll gradually changed into blue-yellow which secrete the mucous substances on the agar media. The cell was flew out the contained substances itself on leaving the cell wall only, or the various micro-organism diffused on the outer-region of the cell.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.21-31
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• 2018

This paper presents an experimental investigation on the structural performance of precast ribbed panel specimens and bridge deck specimens fabricated from the panels. The panel specimens are developed for permanent deck forms of railway bridges (PSC girder). The decks of railway bridges have short lengths compared with highway bridges. Therefore, precast panels for railway bridges are different from those of highway bridges. The precast panels have ribs designed for crack control at the bottom of the sections. Two kinds of specimens were examined: one with 400-mm width and one with 1200-mm width. Three specimens of each type were fabricated, and a total of 12 specimens were tested. In this test, the ultimate load, strain of the reinforcement and concrete, crack width, deformation, and slip were measured. The structural performance of the specimens was assessed using the Korea railway bridge design code and Eurocode. All specimens met the current design criteria for structural strength and serviceability.

• Microbiology and Biotechnology Letters
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• v.44 no.4
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• pp.504-511
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• 2016

Lactulose, a synthetic disaccharide, has received increasing interest because of its role as a prebiotic that can increase the proliferation of Bifidobacterium and Lactobacillus spp. and enhance the absorption of calcium and magnesium. While the industrial production of lactulose is still mainly achieved by the chemical isomerization of lactose in alkaline media, this process has drawbacks including the need to remove catalysts and by-products, as well as high energy requirements. Recently, the use of cellobiose 2-epimerase (CE) has been considered an interesting alternative for industrial lactulose production. In this study, to develop a process for enzymatic lactulose production using CE, we screened improved mutant enzymes ($CS-H^RC^E$) from a library generated by an error-prone PCR technique. The thermostability of one mutant was enhanced, conferring stability up to $75^{\circ}C$, and its lactulose conversion yield was increased by 1.3-fold compared with that of wild-type CE. Using a recombinant Escherichia coli strain harboring a CS35 $H^RC^E$-expressing plasmid, we prepared cell beads immobilized on a Ca-alginate substrate and optimized their reaction conditions. In a batch reaction with 200 g/l lactose solution and the immobilized cell beads, lactose was converted into lactulose with a conversion yield of 43% in 2 h. In a repeated 38-plex batch reaction, the immobilized cell beads were relatively stable, and 80% of the original enzyme activity was retained after 4 cycles. In conclusion, we developed a reasonable method for lactulose production by immobilizing cells expressing thermostable CE. Further development is required to apply this approach at an industrial scale.

• Korean Journal of Food Science and Technology
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• v.22 no.2
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• pp.221-226
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• 1990

Fish flesh of Alaska pollack containing 5% of corn starch were fermented with 8 strains of mold and monitoring of their flavor characteristics, acceptability, nucleotides and their related compounds, amino acid compositions were conducted. All strains were grown vigorously on fish flesh media and formed their characteristic spores with unique flavor by strains. Amino type nitrogen $(NH_2-N)$ content of fermented fish flesh (FFF) were 25-26 times higher than that of raw flesh and 6-15 times higher in extractable nitrogen (Ex-N) content . The strains which produce more ADP (Adenosine 5'-diphosphate) in FFF also showed much higher level of IMP (Inosine 5'-monophosphate) and GMP (Guanosine 5'-monophosphate) content than that of raw flesh. Amino acid composition were differ by strain but lysine was generally highest and arginine, glutamic acid, leucine and alanine in order In review of sensory evaluation , total content of nucleotides, $NH_2-N$, Ex-N and amino acid compositions, suitable strains for fish flesh fermentation were Aspergillus oryzae KFCC 11371, Asp. oryzae KFCC 32343, Penicillium roqueforti KFCC 11269 and Asp. quercinus.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.1
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• pp.77-89
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• 2020

Submerged floating tunnel (SFT) is a type of tunnel that allows tunnel segments to float underwater by buoyancy, and is being actively studied in recent years. When the submerged floating tunnel is connected to the ground, the tunnel and the bored tunnel inside the ground must be connected. There is risk that the stress will be concentrated at the connection between the two tunnels due to the different constraints and behavior of the two tunnels. Therefore, special design and construction methods should be applied to ensure the stability around the connection. However, previous studies on the stability at the connection site have not been sufficiently carried out, so study on the basic stage of the stability at connection site are necessary. In this study, numerical analysis simulating the connection between submerged floating tunnel and the bored tunnel confirmed that the shear strain concentration occurred in the ground around the connection, and it was analyzed that the structural factors can be handled during construction to have effects on the stability of the ground around the connection. Numerical results show that the risks from disproportionate displacements in the two tunnels can be mitigated through the construction of grouting material and joint design. Although the results from this study are qualitative results, it is expected that it will contribute to the determination of structural factors and risk areas that should be considered in the design of connections between the submerged floating tunnel and bored tunnel in the future studies.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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• v.4 no.1
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• pp.71-87
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• 1998

Even though appropriate immune response is necessary for the survival of the individual, excessive or insufficient immune Response might cause autoimmune or allergic disease. So the immune response must be controlled to the degree that is beneficial for the well being of the individual. This study was undertaken to know the effects of Gunleetang Gagambang on the immune system of the mouse. Gunleetang Gagambang has been used for cure of tumor as a traditional medicine without any experimental evidence to support the rational basis for its clinical use. This study was carried out to evaluate the possible therapeutic or antitumoral effects of Gunleetang Gagambang extract against tumor, and to carry out some mechanisms responsible for its effect. Some kinds of tumor were induced by the typical application of 3-methylcholanthrene(MCA) or by the implantation(s.c) of malignant tumor cells such as leukemia cells(3LL cells) or sarcoma cells(S180 cells). Treatment of the Gunleetang Gagambang on water-extract(dailly 1mg/mouse, i. p.) was continued for 7 days prior to tumor induction and after that the treatment was lasted for 20 days. Against squamous cell carcinoma induced by MCA, Gunleetang Gagambang decreased not only the frequency of tumor production but also the number and the weight of tumors per tumor bearing mice(TBM). Gunleetang Gagambang on also significantly suppressed the development of 3LL cell and S180 cell-implanted tumors in occurrence-frequency and their size. and some developed tumors were regressed by the continuous treatment of Gunleetang Gagambang extract into TBM. In vitro, treatment of Gunleetang Gagambang extract had no effect on the growth of some kinds of cell line such as FsaII, A431 strain but significantly inhibited the proliferation of 3LL, S180 cells and augmented the DNA synthesis of mitogen-activated lymphocytes. Gunleetang Gagambang also stimulated the migrative ability of leukocyte, the MIF and IL-2 production of T lymphocytes, but not IL 6 production of B cells. Gunleetang Gagambang administration to mice enhanced NK cells activities. These results demonstrated that Gunleetang Gagambang extract exhibited a significant prophylactic benefits against tumors and its antitumor activity was manifested depending on the type of tumor cells. And these results also suggested that effect of Gunleetang Gagambang might be chiefly due to nonspecitie enhancement of NK cell activities and cell-mediated immune responses.

• Microbiology and Biotechnology Letters
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• v.41 no.4
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• pp.442-448
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• 2013

Lactic acid bacteria (LAB) are a representative group of probiotics and used in many fermented foods and beverages. Several recent studies have shown that LAB are present in makgeolli which is a traditional Korean alcoholic beverage. However, most LAB are intolerant of more than 6% (v/v) alcohol concentrations. For this reason, alcohol-tolerant LAB are isolated from kimchi, makgeolli and nuruk using alcohol containing selective media. After being cultured in MRS broth containing 13% (v/v) alcohol, the two strains which showed the highest increasing O.D values, were finally selected. As results of 16S rRNA gene sequencing and biochemical characterization using an API kit, the two species were identified as Pediococcus acidilactici K3 and S1. In addition, the identified two strains produced bacteriocins against Staphylococcus aureus. When compared with the P. acidilactici type strain, the two selected strains possessed two to three time higher growth on 12-13% (v/v) alcohol containing MRS broth. The viability of P. acidilactici K3 and S1 when inoculated in makgeolli and stored at $10^{\circ}C$ did not decrease through a period of one month indicating that the selected strains can be used for LAB containing makgeolli.

• Journal of Microbiology and Biotechnology
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• v.23 no.11
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• pp.1500-1508
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• 2013

Ebosin, a novel exopolysaccharide produced by Streptomyces sp. 139, has obvious antirheumatic arthritis activity in vivo, and its biosynthesis gene cluster (ste), consisting of 27 open reading frames, has been identified. This paper reports our study of the gene functionality of ste8, the predicted protein product of which is homologous to some bacterial chain length determinant Wzz proteins. For characterization of Ste8, ste8 was cloned and expressed in the mutant strain E. coli 086:H2 (${\Delta}wzz$). The functional complementation of wzz by ste8 was demonstrated by the restoration of wild-type lipopolysaccharide biosynthesis and increased levels of serum resistance of E. coli 086:H2 (${\Delta}wzz$) (pET30a-ste8). To examine the function of ste8 in ebosin biosynthesis, the gene was knocked out with a double crossover via homologous recombination. The molecular weight of the ebosin derivative EPS-8m produced by the mutant Streptomyces sp. 139 ($ste8^-$) was much lower than that of ebosin, and the binding activity of EPS-8m for IL-1R decreased significantly compared with ebosin. These results demonstrate that ste8 encodes a chain length determinant (Wzz) that functions in ebosin biosynthesis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.604-609
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• 2016

This study evaluated the long-term performance of RSR (Reinforced Subgrade for Railways) technology which increases the railway line capacity without the need for additional land. Its characteristics include the use of a short reinforcement with rigid wall, which make it possible to apply it in confined spaces. The 7m high and 40m long testbed employed to evaluate the long-term performance was designed and constructed near Jupo station on the Chang-hang line. This line, located close to a local bus route, had collapsed at the subgrade following heavy rainfall. The performance of the new type of subgrade was verified with long term measurements over a 2 year period including the surface and ground settlement, horizontal displacement of the wall, tensile strain of the reinforcement, and settlement of the rail top on the side track. Based on the results of the measurements made until now, we concluded that it had sufficient safety and serviceability for use as a railway subgrade. It is expected that RSR technology could be frequently used at sites which lack the necessary construction materials for an embankment and are located close to functional railway lines and boundaries, in order to settle civil complaints.