• 제목/요약/키워드: Resistance characteristics

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Reaction Mechanism and Curing Characteristics of Chicken Feather-Based Adhesives and Adhesive Properties of Medium-Density Fiberboard Bonded with the Adhesive Resins (닭털로 제조한 접착제의 반응기작 및 경화 특성과 이를 이용하여 제조한 중밀도섬유판의 접착 특성)

  • Yang, In;Park, Dae-Hak;Choi, Won-Sil;Oh, Sei Chang;Ahn, Dong-uk;Han, Gyu-Seong
    • Korean Chemical Engineering Research
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    • v.55 no.3
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    • pp.385-394
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    • 2017
  • In this study, reaction mechanism and curing characteristics of adhesives formulated with NaOH- and $H_2SO_4$-hydrolyzed chicken feather (CF) and formaldehyde-based crosslinkers were investigated by FT-IR and DSC. In addition, adhesive properties and formaldehyde emission of medium-density fiberboards (MDF) applied with the adhesives were measured. CF-based adhesives having a solid content of 40% and over were very viscous at $25^{\circ}C$, but the viscosity reduced to $300{\sim}660m{\cdot}Pa{\cdot}s$ at $50^{\circ}C$. Consequently, the adhesives could be used as a sprayable resin. Through the FT-IR spectra of liquid and cured CF-based adhesives, addition reaction of methylol group and condensation reaction between the functional groups with the use of formaldehyde-based crosslinkers were identified. From the analysis of DSC, it was elucidated for CF-based adhesives to require a higher pressing temperature or longer pressing time comparing to commercial urea-formaldehyde (C-UF) resin. MDF bonded with CF-based adhesives, which was formulated with 5% NaOH-hydrolyzed CF (CF-AK-5%) and PF of formaldehyde to phenol mole ratio of 2.5 (PF-2.5), and pressed for 8 min had higher MOR and IB than those with other CF-based adhesives. MOR and IB of MDF bonded with the CF-based adhesives regardless of formulation type and pressing time were higher than those with C-UF resin. When the values compared with the minimum requirements of KS standard, IB exceeded the KS standard in all formulations and pressing time, but MOR of only MDF bonded with CF-AK-5% and PF-2.5 and pressed for 8 min satisfied the KS standard. What was worse, 24-TS of MDF bonded with all CF-based adhesives did not satisfied the KS standard. However, MOR and 24-TS can be improved by increasing the target density of MDF or the amount of wax emulsion, which is added to improve the water resistance of MDF. Importantly, the use of CF-based adhesives decreased greatly the formaldehyde emission. Based on the results, we reached the conclusion that CF-based adhesives formulated under proper conditions had a potential as a sprayable resin for the production of wood panels.

Screening of Resistant Chinese Cabbage Cultivar against Clubroot (Plasmodiophora brassicae) for Cultivation in Highland (고랭지 배추재배를 위한 뿌리혹병 저항성 품종선발)

  • Yoon, Cheol-Soo;Jung, Eun-Kyoung;Lee, Sang-Jun;Zhang, Yan;Lee, Jae-Eun;Kim, Byung-Sup
    • Research in Plant Disease
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    • v.16 no.1
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    • pp.59-65
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    • 2010
  • This study was conducted to select the cultivars and strains which are suitable in cultivation of the Chinese cabbage having good horticultural characteristics and the resistance to clubroot caused by Plasmodiophora brassicae, which is a widespread disease that causes serious problems in many Brassica growing areas. Thirty four cultivars and nineteen strains of the Chinese cabbage were planted in the contaminated fields in highland and investigated the wilting symptom due to the initial disease occurrence and high temperature. Disease occurrence rate and severity of clubroot and the horticultural characteristics were also examined. According to the results, Bulamplus, Kangryeokyeoleumbaechu among cultivars of Chinese cabbage, SP-05, SP-02, CR DB 50, and CR DB 29 among strains of Chinese cabbage were resistant to hot weather by showing delayed above-ground symptom (wilting) of clubroot in 30 days after transplanting. In case of below-ground clubroot rate, Daetong, super CR Kimi 85 and super CR Hiroki among the cultivars of Chinese cabbage were resistant to clubroot in 60 days after transplanting. When fresh weight of Chinese cabbage among cultivars were compared, super CR Hiroki of over 2,500 g was the highest among other cultivars. Although the resistant and susceptible reactions of Chinese cabbage cultivars and strains against clubroot disease were somewhat different from the above-ground symptoms (wilting) of clubroot in 30 days and below-ground symptoms of clubroot in 60 days, we recommend that super CR Hiroki, CR Kimi 85, CR Janggun among cultivars of Chinese cabbage and CR DB 50 and CR DB 29 among strains of Chinese cabbage will be more suitable in cultivation of Chinese cabbage in highland.

The Clinical and Radiology Characteristics of Diabetic or Non-diabetic Tuberculosis Patients: a Retrospective Study (당뇨병 환자와 정상 혈당 환자에서 폐결핵의 임상적, 방사선학적 차이)

  • Park, Hyung Wook;Do, Kyong Rock;Jeon, Eun Kyoung;Park, Jin Young;Lee, Ja Young;Kim, Ji Eun;Park, Young Kun;Lee, Sang Rok;An, Jin Young
    • Tuberculosis and Respiratory Diseases
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    • v.64 no.4
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    • pp.259-265
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    • 2008
  • Background: Patients with diabetes mellitus are highly sensitive to infections, including tuberculosis, and the longer the duration of DM, the greater is the prevalance of tuberculosis. We studied the difference of the clinical manifestations, radiologic findings, resistance and others factors of patients with diabetic and non-diabetic pulmonary tuberculosis. Methods: The patients we enrolled in this study were newly diagnosed with pulmonary tuberculosis from January 2003 to December 2005. Results: 159 patients were enrolled in this study. There were 30 pulmonary tuberculosis patients with diabetic mellitus (DMTB) and 129 pulmonary tuberculosis patients without diabetic mellitus (non-DMTB). There was no difference in the basic characteristics and clinical manifestation between both the groups. For the chest X-ray findings, the moderately advanced tuberculosis patients were the most common (43.3% in the DMTB group and 49.6% in the non-DMTB group). There was no relation between the severity of tuberculosis activity on chest x-ray and the presence of diabetes. The prevalence of cavitory lesions in the DMTB group was significantly higher than that in the non-DMTB group, but the prevalence of atelectasis was higher in the non-DMTB group (p<0.05). There was no difference in the incidence of lower lung involvement, the number of involved lobes, the number of treatment days and the radiological sequelae in both groups. Conclusion: The DMTB patients had a higher incidence of cavitory lesions and a higher incidence of atelectasis than the non-DMTB patients.

A Study on the Degree of Need of Human Structure and Function Knowledge in Clinical Nurses (기초간호자연과학의 인체구조와 기능 내용별 필요도에 대한 연구)

  • Choe, Myoung-Ae;Byun, Young-Soon;Seo, Young-Sook;Hwang, Ae-Ran;Kim, Hee-Seung;Hong, Hae-Sook;Park, Mi-Jung;Choi, Smi;Lee, Kyung-Sook;Seo, Wha-Sook;Shin, Gi-Soo
    • Journal of Korean Biological Nursing Science
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    • v.1 no.1
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    • pp.1-24
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    • 1999
  • The purpose of this study was to define the content of requisite human structure and function knowledge needed for clinical knowledge of nursing practice. Subjects of human structure and function were divided into 10 units, and each unit was further divided into 21 subunits, resulting in a total of 90 items. Contents of knowledge of human structure and function were constructed from syllabus of basic nursing subjects in 4 college of nursing, and textbooks published by nurse scholars prepared with basic nursing sciences. The degree of need of 90 items was measured with a 4 point scale. The subjects of this study were college graduated 136 nurses from seven university hospitals in Seoul and three university hospitals located in Chonnam Province, Kyungbook Province, and Inchon. They have been working at internal medicine ward, surgical ward, intensive care unit, obstetrics and gynecology ward, pediatrics ward, opthalmology ward, ear, nose, and throat ward, emergency room, rehabilitation ward, cancer ward, hospice ward, and their working period was mostly under 5 years. The results were as follows: 1. The highest scored items of human structure and function knowledge necessary for nursing practice were electrolyte balance, blood clotting mechanism and anticoagulation mechanism, hematopoietic function, body fluid balance, function of plasma, and anatomical terminology in the order of importance. The lowest scored items of human structure and function knowledge necessary for nursing practice was sexual factors of genetic mutation. 2. The highest order of need according to unit was membrane transport in the living unit, anatomical terminology in movement and exercise unit, mechanism of hormone function in regulation and integration unit, component and function of blood in oxygenation function unit, structure and function of digestive system in digestive and energy metabolism unit, temperature regulation in temperature regulation unit electrolyte balance in body fluid and electrolyte unit, concept of immunity in body resistance unit, and genetics terminology in genetics unit. The highest order of importance according to subunit was membrane transportation in cell subunit, classification of tissues in tissue unit, function of skin and skin in skin subunit, anatomical derivatives of the skeleton subunit, classification of joints in joint subunit, an effect of exercise on muscles in muscle subunit, function of brain in nervous system subunit, special sense in sensory subunit mechanism of hormone function in endocrine subunit, structure and function of female reproductive system in reproductive system unit, structure and function of blood in blood unit, structure of heart, electrical and mechanical function in cardiovascular system unit, structure of respiratory system in respiratory system subunit, structure and function of digestive system in digestive system subunit, hormonal regulation of metabolism in nutrition and metabolism subunit, function of kidney in urologic system subunit, electolyte balance in body fluid, electolyte and acid-base balance subunit. 3. The common content of human structure and function knowledge need for all clinical areas in nursing was structure and function of blood, hematopoietic function, function of plasm, coagulation mechanism and anticoagulation mechanism, body fluid, electrolyte balance, and acid-base balance. However, the degree of need of each human structure and function knowledge was different depending on clinical areas. 4. Significant differences in human structure and function knowledge necessary for nursing practice such as skin and derivatives of the skin, growth and development of bone, classification of joint, classification of muscle, structure of muscle, function of muscle, function of spinal cord, peripheral nerve, structure and function of pancrease, component and function of blood, function of plasma, structure and function of blood, hemodynamics, respiratory dynamics, gas transport, regulation of respiration, chemical digestion of foods, absorption of foods, characteristics of nutrients, metabolism and hormonal regulation, body energy balance were demonstrated according to the duration of work. 5. Significant differences in human structure and function knowledge necessary for nursing practice such as classification of tissue, classification of muscles, function of muscles, muscle metabolism, classification of skeletal muscles, classification of nervous system, neurotransmitters, mechanism of hormone function, pituitary and pituitary hormone, structure and function of male reproductive organ, structure and function of female reproductive organ, component and function of blood, function of plasma, coagulation mechanism and anticoagulation mechanism, gas exchange, gas transport, regulation of respiration, characteristics of nutrients, energy balance, function of kidney, concept of immunity, classification and function of immunity were shown according to the work area. Based on these findings, all the 90 items constructed by Korean Academic Society of Basic Nursing Science should be included as contents of human structure and function knowledge.

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Effects of Maltogenic Amylase on Textural Properties of Dough and Quality Characteristics of White Pan Bread (Maltogenic Amylase가 식빵반죽의 물성과 식빵의 품질 특성에 미치는 영향)

  • Yoon, Seongjun;Cho, Namji;Lee, Soo-Jeong;Moon, Sung-Won;Jeong, Yoonhwa
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.44 no.5
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    • pp.752-760
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    • 2015
  • Effects of maltogenic amylase on textural properties of dough and quality characteristics of white pan bread were investigated. White pan bread was prepared with four different levels of maltogenic amylase contents (M-1: 0.048 U/g, M-2: 0.060 U/g, M-3: 0.072 U/g, M-4: 0.084 U/g). The setback by amylograph for the control was $480.0{\pm}12.25$ Brabender Unit (B.U.) while M-4 showed the a setback of $215.0{\pm}5.00B.U.$ The absorption, mixing tolerance index, and stability by farinogram were not significantly different (P>0.05) for across all treatments. The area under the curve (135 min) by extensogram was higher than all samples. The texture profile analysis results showed that there was significant decreasing in hardness for the maltogenic amylase infused bread (P<0.05). M-3 and M-4 showed higher springiness and cohesiveness but lower hardness than control over 1 to 3 days, indicating possibly extended shelf-life. Imaging scan showed that air cell size less than $0.4mm^2$ for the control and M-4 were at rates of 94.90% and 95.70%, respectively. For sensory evaluation, M-3 and M-4 showed higher intensities than the control for taste, flavor, texture, mouthfeel, and moistness quality. These results imply that the quality of white pan bread could be improved by adding maltogenic amylase without the use of chemical additives.

Effect of Seed Method and Seeding Rate on the Agronomic Characteristics and Yield of Forage Barley (파종방법 및 파종량이 사료용 보리의 생육특성 및 수량에 미치는 영향)

  • Kim, W.H.;Seo, S.;Shin, J.S.;Lim, Y.C.;Kim, K.Y;Choi, K.C.;Kim, C.H.
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.24 no.4
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    • pp.317-323
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    • 2004
  • This study was carried out to determine the effect of seed method and seeding rate on the desirable agronomic characteristics and yield of forage barley(Hordeum vuigare) at paddy field, National Livestock Research Institute, RDA, Suwon from October 2001 to May 2003. The experiment was arranged in a spilt plot design with three replications. Main plots consisted of tow seed method; Broadcasting and drilling, Sub-plots consisted of seeding rates; 130. 160, 190 and 220 kg/ha. The results obtained were summarized as fellows ; The resistance of cold, disease and lodging of barley for the seeding method and seed rate were not different. And dry matter percentage of barley for a seeding method of 130 kg/ha at the broadcasting was the lowest of $32.0\%$, and that for the drilling at 130 kg/ha was $32.7\%(P<0.05). Fresh yield of barley for a seeding method of drilling at 130 kg/ha was the highest of 32,073 kg/ha, and that for a seeding method of broadcasting at 130 kg/ha was the lowest of 20,944 kg/ha(P<0.05). Dry matter yield of barley for a seeding method of drilling at 160 and 130 kg/ha were the highest 9,170 and 9,138 kg/ha, and that fur a seeding method of broadcasting at 130 kg/ha was the lowest of 5,710 kg/ha(P<0.05). Based on the results of this experiment, it appears that the seeding method and rate of barley could be enhanced by drilling from 130 to 160 kg/ha, and broadcasting from 190 to 220 kg/ha. respectively.

Growth Characteristics, Seed and Forage Productivity of New Naked Oat (Avena nuda L.) Cultivar "Jungmo2005" (귀리 품종 '중모2005'의 생육특성과 종실 및 조사료 생산성)

  • Han, Ouk-Kyu;Park, Tae-Il;Park, Hyung-Ho;Park, Ki-Hun;Oh, Young-Jin;Ku, Ja-Hwan;Kweon, Soon-Jong;Ahn, Jong-Woong
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.37 no.1
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    • pp.28-34
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    • 2017
  • A new naked oat cultivar, 'Jungmo2005'(Avena nuda L.), was developed for food and forage use by National Institute of Crop Science, RDA in 2010. It was derived from a cross between $F_1$['Early80'/'Gwiri33'] and $F_1$['Early80'/'Gwiri23']. 'Early80', a covered oats, has early heading and high yielding, while 'Gwiri23' of covered type and 'Gwiri33' of naked type has early heading with large-size grain. 'Jungmo2005' has the characteristics of narrow and long leaves of pale green color, middle diameter culm of yellow color and medium grain of whitish yellow color. Cultivar 'Jungmo2005' had 2 days earlier heading date (May 9) than the check cultivar 'Seonyang' (May 11) in field condition. The 'Jungmo2005' showed better winter hardiness than that of the check cultivar, and similar to the check cultivar in respect to lodging resistance. The 'Jungmo2005' had 105 cm of culm length, 21.5 cm of spike length, 658 spikes per $m^2$, 82 grains per spike, 23.3 g of 1,000-grain weight, and 622 g of test weight. The grain yield of 'Jungmo2005' was averaged $3.38MT\;ha^{-1}$, which was 6% higher than that of the check. Average forage fresh and dry matter yield of 'Jungmo2005' harvested at milk-ripe stage were 44.8 and $12.6tone\;ha^{-1}$, respectively, compared with 47.5 and $12.5tone\;ha^{-1}$ of the check. The protein content of the 'Jungmo2005' was similar to the check (7.6% and 7.5%, respectively), while ADF (28.6%) and NDF (51.5%) were lower than the check (31.4% and 57.0%, respectively). TDN content and RFV were higher than those of the check (66.3%, 120.3 and 64.1, 105.2, respectively). 'Jungmo2005' is recommended for fall sowing cropping only in the south area where daily minimum mean temperatures are averaged higher than $-4^{\circ}C$ in January, and it should not be cultivated in mountain areas, where frost damages is likely to occur. The areas would do better only to sow in spring season.

Shear Strength and Erosion Resistance Characteristics of Stabilized Green Soils (토양안정재를 혼합한 녹생토의 전단강도 및 침식저항특성)

  • Oh, Sewook;Jeon, Jinchul;Kim, Donggeun;Lee, Heonho;Kwon, Youngcheul
    • Journal of the Korean GEO-environmental Society
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    • v.16 no.12
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    • pp.45-52
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    • 2015
  • With the rising interest in the environment, more attention on ecological restoration for damaged slope surface to restore its original state has been drawn. Generally, the most useful method is vegetation based spray work. This method uses green soil including sewage sludge, sawdust, paper sludge, and weathered granite soil. However, because there are neither accurate information nor test values about green soil, green soil is often lost by environmental factors such as rainfalls and strong winds. To solve the problem of green soil, it is necessary to prepare design standards about green soil, and conduct studies to deal with green soil loss in consideration of various variables including basic material property, soil quality of slope surface, and weather. This study was conducted in the mixture of green soil and eco-friendly soil stabilizer. With green soil, basic material property test and compaction test were conducted for the analysis on the basic characteristics of green soil. In the mixture with soil stabilizer at a certain ratio, we conducted shear strength test depending on the ratio in order to analyze the maximum shear strength, cohesion and the change in internal friction angles. Furthermore, in the mixture ratio of green soil and soil stabilizer, which is the same as the ratio in the shear strength test, an inclination of slope surface was made in laboratory for the analysis on erosion and germination rate. Finally, this study evaluated the most effective and economic mixing ratio of soil stabilizer to cope with neighboring environmental factors. According to the test, the shear strength of green soil increased up to 51% rely onto the mixing ratio of and a curing period, and its cohesion and internal friction angle also gradually increases. It is judged that the mixture of soil stabilizer was effective in improving shear strength and thereby increased the stability of green soil.

Fermentation characteristics of Campbell Early wine by indigenous Saccharomyces cerevisiae yeasts with resistance to potassium metabisulfite and a high sugar concentration (아황산 및 당 내성을 가진 토착형 Saccharomyces cerevisiae 효모에 의한 캠벨얼리 포도주의 발효 특성)

  • Kim, Mi-Sun;Yeo, Soo-Hwan;Park, Heui-Dong
    • Food Science and Preservation
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    • v.20 no.5
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    • pp.744-750
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    • 2013
  • The indigenous Saccharomyces cerevisiae strains S13 and D8 were isolated at the microbial succession stage during spontaneous fermentation of Campbell Early wine as a resistant to potassium metabisulfite and a high sugar concentration. In this study, the fermentation characteristics of Campbell Early wine were investigated and compared with those of S. cerevisiae W-3, an industrial wine yeast. Alcohol production by the two strains was delayed at the initial fermentation stage, but increased fast when the fermentation continued. After the fermentation, the S13 and D8 wines contained 12.6% and 13.2% (v/v) alcohol, respectively, which were significantly higher than the alcohol content of the W-3 wine (12%, v/v). No marked differences were observed in the residual soluble solid content and the pH. However, the S13 and D8 wines showed high levels of total acid content, including malic and lactic acids. Especially, the lactic acid content was 8.9-fold in the S13 wine and six-fold in the D8 wine, compared with that of the W-3 wine. The two strains produced a higher level of acetaldehyde and a lower amount of methanol in the wine than the W-3 strain. The iso-Butanol content was lower in the two indigenous yeast wines with similar levels of n-propanol and iso-amyl alcohol contents than that in the W-3 wine. In the sensory evaluation, the S13 and D8 wines had higher scores for their color, flavor, taste and overall preferences than the W-3 wine. Especially, the S13 and D8 wines had much higher scores than the W-3 wine for flavor and color, respectively.

Identification and Characterization of Lactobacillus salivarius subsp. salivarius from Korean Feces

  • Bae, Hyoung-Churl
    • Proceedings of the Korean Society for Food Science of Animal Resources Conference
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    • 2004.05a
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    • pp.89-119
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    • 2004
  • This study was conducted to isolate lactobacilli having probiotic characteristics to be used as health adjuncts with fermented milk products. Acid tolerant strains were selected in Lactobacilli MRS broth adjusted to pH 4.0 from 80 healthy persons (infants, children and adults). And bile tolerant strains were examined in Lactobacilli MRS broth in which 1.0% bile salt was added. By estimation above characteristics, the strains No. 27, which was isolated from adult feces, was selected and identified as Lactobacillus salivarius subsp. salivarius based on carbohydrate fermentation and 16S rDNA sequencing. It was used as a probiotic strain in fermented milk products. The pH of fermented milk decreased from pH 6.7 to 5.0 and titratable acidity increased from 0.3% to 1.0% by L. salivarius subsp. salivarius (isolation strain 20, 35, and 37), when incubated for 36 h at $37^{\circ}C$. The number of viable cell counts of fermented milk was maximized at this incubation condition. The SDS-PAGE evidenced no significant change of casein but distinct changes of whey protein were observed by isolated L. salivarius subsp. salivarius for titratable acidity being incubated by $0.9{\sim}1.0%$ at $37^{\circ}C$. All of the strains produced 83.43 to 131.96 mM of lactic acid and 5.39 to 26.85 mM of isobutyric acid in fermented products. The in vitro culture experiment was performed to evaluate ability to reduce cholesterol levels and antimicrobial activity in the growth medium. The selected L. salivarius subsp. salivarius reduced $23{\sim}38%$ of cholesterol content in lactobacilli MRS broth during bacterial growth for 24 hours at $37^{\circ}C$. All of the isolated L. salivarius subsp. salivarius had an excellent antibacterial activity with $15{\sim}25$ mm of inhibition zone to E. coli KCTC1039, S. enteritidis KCCM3313, S. typhimurium M-15, and S. typhimurium KCCM40253 when its pH had not been adjusted. Also, all of the isolated L. salivarius subsp. salivarius had partial inhibition zone to E. coli KCTC1039, E. coli KCTC0115 and S. enteritidis KCCM3313 when it had been adjusted to pH 5.7. The selected strains were determined to have resistances of twelve antibiotic. Strains 27 and 35 among the L. salivarius subsp. salivarius showed the highest resistance to the antibiotics. Purified ${\alpha}$-galactosidase was obtained by DEAE-Sephadex A-50 ion exchange chromatography, Mono-Q ion exchange chromatography and HPLC column chromatography from L. salivarius subsp. salivarius 27. The specific activity of the purified enzyme was 8,994 units/mg protein, representing an 17.09 folds purification of the original cell crude extract. The molecular weight of enzyme was identified about 53,000 dalton by 12% SDS-PAGE. Optimal temperature and pH for activity of this enzyme were $40^{\circ}C$ and 7.0 respectively. The enzyme was found to be stable between 25 and $50^{\circ}C$. ${\alpha}$-galactosidase activity was lost rapidly below pH 5.0 and above pH 9.0. This enzyme was liberated galactose from melibiose, raffinose, and stachyose, and also the hydrolysis rate of substrate was compound by HPLC. These results indicated that some of the L. salivarius subsp. salivarius (strain 27 and 35) are considered as effective probiotic strains with a potential for industrial applications, but the further study is needed to establish their use as probiotics in vivo.

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