• Microbiology and Biotechnology Letters
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• v.20 no.6
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• pp.647-654
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• 1992

In order to study the physiological properties of the intestinal bacteria, we isolated the intestinal bacteria of Koreans and tested the enzymatic patterns. Isolated Bifidobacterium sp. Int-57 had the higher activity of $\alpha$-glucosidase, $\beta$-glucosidase, $\alpha$-galactosidase, $\beta$-galactosidase. $\beta$-xylosidase and $\alpha$-arabinofuranosidase than other intestinal microorganisms. The effect of the carbon sources on the production of each enzymes of Bijidobacterium sp. Int-57 was investigated. The most suitable carbon source for the production of $\beta$-glucosidase was maltose, for a-glucosidase cellobiose, for $\alpha$-galactosidase raffinose, for $\beta$-galactosidase lactose, and for $\beta$-xylosidase and $\alpha$-arabinofuranosidase xylose, respectively. In addition, we investigated the optimal conditions and pH stability of each crude enzymes. The optimal condition of a-glucosidase was pH 6.0 and $40^{\circ}C$. that of Jj-glucosidase pH 7.0 and 50oe, that of $\beta$-galactosidase pH 7.0 and $50^{\circ}C$, that of $\beta$-xylosidase pH 6.0 and $40^{\circ}C$ , and that of $\alpha$-arabinofuranosidase pH 5.0 and $50^{\circ}C$. respectively. a-Glucosidase was stable at pH 4.0-9.0. Jj-glucosidase at pH 4.0-7.0. $\beta$-galactosidase at pH 4.0-9.0, $\beta$-xylosidase at pH 4.0-6.0, and /3-arabinofuranosidase at pH 7.0-9.0, respectively.

• Journal of Food Hygiene and Safety
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• v.13 no.3
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• pp.313-317
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• 1998

This study was perfonned to investigate the possible effect of Bacillus subtilis which is the predominant species of bacteria in Korean soy sauce, soy paste, and Meju (soybean cake) on the growth and aflatoxin production of Aspergillus parasiticus ATCC 15517. The microorganisms were grown in a modified APT broth and incubated at $30^{\circ}C$ for 12 days. Aflatoxins were determined using high performance liquid chromatography (HPLC). A remarkable inhibition of the growth of Aspergillus parasiticus was observed during the incubation period when in the presence of B. subtilis (mixed culture). Dry mycelial weight in the mixed culture was significantly reduced by 85.3% in comparison to the control at the end of the incubation period (p<0.01). Lower levels of aflatoxins were found in the mixed culture than in the monoculture. At the end of the incubation period aflatoxin production was significantly inhibited by more than 50% (p<0.05). These results indicate that B. subtilis mainly inhibites the growth and aflatoxin production of toxigenic Aspergillus in Meju, soy sauce and soy paste. Although its effect on aflatoxin production was less pronounced, we could expect more inhibition by another bacteria related with fermentation in Meju.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.24-30
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• 2018

As the demand for underground space increases, many researchers have been studying the load reduction method using high compressible materials to solve for the stability problem of the overhead load and for the increase of the earth pressure which decreases the function of the underground structure. This paper determines the optimum soft zone and the effect of the using EPS Geofoam as a load reduction material to arch structures. A finite element analysis program, ABAQUS, is used to analyze the soil-structure interaction and the behavior of buried arch structures considering different four EPS Geofoam forms to confirm the most conservative shape. The optimum cross-sectional shape was determined by comparing the results of earth pressure reduction rate in accordance with the change of span-rise ratio and span length of the arch structure. It was confirmed that the earth pressure generated in the arch structure using the optimal soft zone selected by the numerical analysis was reduced by an average of 78%. In this study, the effect of EPS Geofoam on soil pressure reduction and its applicability to underground arch structures will provide an economical and conservative way to design underground structures and will help to increase the usability of deep underground space.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.744-756
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• 2018

The purpose of this study was to investigate the anti-inflammatory effect and the antimicrobial activity to skin flora of essential oil from rosemary that naturally grown in Jeju. rosemary essential oil was extracted by water distillation essential oil extraction method. In order to confirm the anti-inflammatory activity of rosemary essential oil, it was confirmed that the production of NO and $PGE_2$ induced by LPS in RAW 264.7 cells was inhibited in a concentration-dependent manner. Western blot analysis showed that the expression of iNOS and COX-2, which are biosynthetic enzymes, decreased in a concentration-dependent manner. In addition, production of $TNF-{\alpha}$ and IL-6 the pro-inflammatory cytokines were inhibited. Antimicrobial activities of three S. epidermidis and three P. acnes strains including two antibiotic resistant strains were observed in paper disc method and MIC and MBC tests showed inhibition of bacterial growth and death. From the results of the experiment, we confirmed that rosemary essential oil has the anti-inflammatory and antimicrobial efficacy and it could be used as a cosmetic and skin care material in the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.667-673
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• 2017

This study was carried out to verify the antimicrobial effect of Graviola leaves against pathogenic bacteria for the purpose of developing an antibacterial material. The extraction conditions of graviola leaves were $60^{\circ}C$, $80^{\circ}C$ and $98^{\circ}C$, and graviloa leaves werewater extracted at $60^{\circ}C$, $80^{\circ}C$ and $98^{\circ}C$.The extraction yields and extraction conditions were determined. The antimicrobial activity against S. epidermidis, S. aureus and E. coli TOP10 was evaluated by agar diffusion method. The extraction yields were 3.02%, 14.73% and 20.76% at $60^{\circ}C$, $80^{\circ}C$ and $98^{\circ}C$, respectively. The antimicrobial activity against S. epidermidis, S. aureus and E. coli TOP10 was found in S. epidermidis.In the samples extracted at $98^{\circ}C$, a clear zone of 13 mm was observed at 200 mg/mL and of 20 mm at 500 mg/mL. The MIC was 100 mg/mL. The higher the extraction temperature and concentration, the better was the growth inhibition effect. As a result, the natural antimicrobial activity contained in natural materials can solve the problem of resistance to antibiotics. It is considered that antimicrobial activity against S. epidermidis in skin is highly applicable to basic cosmetics and cosmetic materials.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.4
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• pp.311-319
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• 2012

Seborrheic dermatitis (SD) is the skin disease occurred because of Malassezia yeast which grows on the skin and scalp, and this yeast lives on sebum lipid, and their metabolite, free lipid acids are thought to be the main irritant on skin. To find out effective cosmeceutical ingredients to treat SD symptoms, we established novel cell-based in vitro model mimicking SD symptoms. This in vitro model adopted the co-culture system with primary sebocyte & HaCaT keratinocyte. We used M. globosa yeast extract, arachidonic acid, linoleic acid and dihydrotestosterone as SD inducers. In the co-culture system with optimized concentrations for SD-inducing cocktail, the production of IL-8 and sebum lipids increased up to 2-fold, and then we screened with commercial essential oils by monitoring IL-8 as a key inflammatory biomarker. Then we found that Cinnamomum zeylanicum oil, Mentha arvensis oil effectively down-regulated IL-$1{\alpha}$, IL-6, IL-8 cytokines which over-produced by SD-inducing cocktail. Additionally, two essential oils also showed inhibitory effect on sebum lipid synthesis from primary sebocyte and growth inhibitory effect to M. globosa yeast (MICs were lower than 0.0625 %). Our recent results suggest that Cinnamomum zeylanicum oil and Mentha arvensis oil could be effective natural herbal remedies to relieve or protect scalp seborrheic dermatitis.

• Journal of Korean Society of Steel Construction
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• v.27 no.1
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• pp.23-30
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• 2015

Developed in this study were Octagonal-hollow-section(OHS) struts, whose compressive strengths against flexural and local buckling is higher than H-shape or rectangular-hollow-section(RHS) struts with the same unit weight. OHS members are also advantageous in handling and storing compared to circular hollow sections(CHS). OHS members were fabricated from HR Plates by cold forming and fillet welding. 5 numbers of 20m long OHS struts were assembled, each of which consist of two 9.6m long OHS member and two end connection elements made of cast iron. The compressive strength of the OHS strut was evaluated by comparing the test results, design codes and FEM analysis each other. Test results show that all of the struts have almost same or larger compressive strength than Korean Road Bridge Design Code(KRBDC) (2012). The initial imperfections can be estimated by using measured strains and are turned out to be less than L/450 for all the struts tested. The results of FEM analysis show that the variation of initial imperfection has less effects on the compressive strength for struts with vertical surcharge than for those with self-weight only, while the strength decreases as the initial imperfection increases. As the result of this study, the allowable initial imperfection for 20m long OHS struts is recommended to be less than L/350 on job sites.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.7
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• pp.1025-1031
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• 2011

The objective of this study was to compare the performances of conventional microbiological media used in isolation of Shigella spp. from foods. Total of six selective media, including MacConkey agar (MAC), Salmonella Shigella agar (SSA), desoxycholate citrate agar (DCA), xylose lysine desoxycholate agar (XLD), hektoen enteric agar (HEA), and CHROMagar, were tested. MAC showed almost the same colony numbers as compared to tryptic soy agar (TSA) while DCA showed significantly lower colony numbers when cultivated Shigella spp. was counted in each medium. In a food recovery test with beef, pork and shrimp, S. sonnei recovered well on CHROMagar (p<0.05). With lettuce and cabbage, S. sonnei displayed significantly significant recovery (p<0.05) on SSA in comparison with other selective media. Heat-injured cells recovered well on MAC and SSA. In a specificity test using Enterobacteriaceae strains, HEA was identified as having the highest specificity among the tested media. However, Morganella spp. could not be differentiated from Shigella spp. on any of the tested selective media. Shigella spp. precluded the possibility of isolation from foods by a single 'best' selective medium. Consequently, a combination of complementary selective media or selection of appropriate media according to cell conditions must be considered for comprehensive isolation.

• Journal of Korean Society of Forest Science
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• v.99 no.6
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• pp.855-862
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• 2010

The objectives of this study were to analyze vegetation types and stand structures of the red pine (Pinus densiflora) in Kangwon southern region for stable and sustainable forest management. The pine forests in study sites were classified into 4 communities, 2 groups, so total 6 vegetation units. Species with high constance degree were Quercus mongolica, Rhus trichocarpa, Lindera obtusiloba, Lespedeza maximowiczii, Quercus serrata, Spodiopogon sibiricus, Aster scaber and Fraxinus sieboldiana. In the importance value(I.V.) analysis of each layer, P. densiflora showed highly in tree layer while in other layers competitive broad-leaved species such as Quercus spp. were high. P. densiflora also showed large size of DBH, while broad-leaved species distributed middle and small DBH. The annual ring growths of P. densiflora and competitive broadleaved species were variable according to area, site condition, tree year and species, it is considered that appropriate silvicultual practice methods should be employed to remove rival broad-leaved species for maintenance of sustainable red pine forests considering the characteristics of each stand.

• The Korean Journal of Ecology
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• v.23 no.5
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• pp.407-421
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• 2000

The forest vegetation surrounding Taegu area was investigated by the methodology of the ZM school of phytosociology, from September, 1994 to August, 1997. The forest vegetation was classified into 7 communities, 8 subcommunities and 5 afforestations as follows : Quercus mongolica community (Typical subcommunity, Carex siderosticta subcommunity), Quercus variabilis community, Quercus acutissima community, Quercus dentate community, Carpinus cordata-Acer mono community (Typical subcommunity, Quercus serrata subcommunity, Cornus controversa subcommunity), Pinus densiflora community (Typical subcommunity, Sanguisorba officinalis subcommunity, Rhododendron schlippenbachii subcommunity), Lespedeza maximowiczii-Rhododendron mucronulatum community , Robinia pseudo-acacia afforestation, Pinus rigida afforestation, Larix leptolepis afforestation, Pinus thunbergii afforestation, Pinus koraiensis afforestation. The differential species of the Quercus mongolica community were Quercus mongolica, Athyrium yokoscense, Rhododendron schlippenbachii, Fraxinus sieboldiana, Acer pseudo-sieboldianum, Symplocos chinensis for. pilosa, Astilbe chinensis var. davidii, Weigela subsessilis, and Melampyrum roseum, those of the Carpinus cordata-Acer mono community were Acer mono, Carpinus cordata, Carpinus laxiflora, and Staphylea bumalda, those of the Pinus densiflora community were Pinus densiflora, Quercus serrata, Cocculus trilobus, and Juniperus rigida. Constance degree of the Quercus serrate was especially high in shrub and herb layers of the Pinus densiflora community. The results of factor analysis by DCA showed that distribution pattern of the communities were similar to that by Z-M method and that communities were arranged according to soil moisture gradient. Rhododendron schlippenbachii subcommunity of the P. densiflora community and the Typical subcommunity of the Q. mongolica community were distributed in similar environments.