• Biomedical Science Letters
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• v.4 no.1
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• pp.1-9
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• 1998

A Corynebacterium diphtheriae iron-repressible gene dirA, that was homologous to TSA of Saccharomyces cerevisiae and AhpC subunit of Salmonella typhimurium alkyl hydroperoxide reductase, was amplified with PCR and expressed in E. coli. The DirA purified from the transformed E. coli crude extracts prevented the inactivation of enzyme caused by metal-catalyzed oxidation (MCO) system containing thiols but not by ascorbate/Fe$^{3+}$/$O_2$ MCO system. The DirA concentration, which inhibited the inactivation of glutamine synthetase by 50% (IC$_{50}$) against MCO system, was 0.12 mg/ml. The multimeric forms of DirA were converted to the monomeric form in SDS-PAGE under the thioredoxin system comprised of NADPH, Saccharomyces cerevisiae thioredoxin reductase, and thioredoxin. Also, DirA showed thioredoxin dependent peroxidase activity. All of these results were consistent with the characteristics of a thiol specific antioxidant (TSA) protein having two conserved cysteine residues.

• Korean Journal of Veterinary Research
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• v.40 no.3
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• pp.525-531
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• 2000

Verotoxin non-producing E coli O157 strains have been isolated from cattle feces and compared in particular regard to biochemical properties and genotypes with verotoxin-producing E coli (VTEC). E coli O157 : nonH7 strains had different phenotypes in sorbitol fermentation and ${\beta}-glucuronidase$ activity from E coli O157 : H7. Regardless of verotoxin production ability of E coli O157 : H7, uidA gene was uniquely detected from sorbitol and ${\beta}-glucuronidase$ negative E coli O157 : H7. Forty five fecal samples from 6 dairy farms were obtained and VTEC was detected as 15.6% (7 strains) of the samples. Most VTEC isolates were positive for sorbitol fermentation and ${\beta}-glucuronidase$ activity but negative for eaeA gene. This study suggested that cattle could be a reservior for VTEC. However, absence of eaeA gene in VTEC isolates from most of healthy cattle suggested that they might be less virulent than eaeA-positive E coli against human health.

• Journal of Wetlands Research
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• v.6 no.2
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• pp.65-71
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• 2004

The most significant effect of excess water in wetlands is the isolation of the soil from the atmosphere and the prevention of O2 from diffusing into soil. The blockage of atmospheric O2 induces biological and chemical processes that change soil from oxidized into reduced state. When dry soil develop into hydric soil, redox potential is dropping. The redox potential is a indicator of hydric soil and affect chemical function of wetlands. To reveal characteristics of wetland soil, redox potential was measured in Jinkwannaedong ecological conservation area from May in 2003 to March in 2004. Redox potentials in May ranged from 5 mV at 25 cm depth to 200 mV at 10 cm depth. It decreased to about -200 m V at all depths and continued until October. In winter, redox potential was slowly increased; it was the highest at 5 cm depth and lowest at 20 cm depth. Annual variations of redox potential in 20 cm depth showed the same pattern at 5 sites; low in growing season and high in non-growing season. This results indicates that soils of study sites are in hydric state and methanogenesis is occurring in Jinkwannaedong ecological conservation area.

• The Korean Journal of Food And Nutrition
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• v.23 no.4
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• pp.664-669
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• 2010

Lactic acid bacteria from traditional Korean foods of Tarak and Kimchi was isolated and characterized against carcinogenic Helicobacter pylori. Five Tarak and 30 Kimchi, traditional lactic acid-fermented foods, were collected from Andong area and the markets in Seoul, respectively and 15 lactic acid bacteria were isolated. Among them, two isolates were selected from high growth-inhibitory activities on H. pylori. The isolates were identified as Streptococcus thermophilus LAB kw15 from Tarak and Leuconostoc mesenteroides LAB kw5 from Kimchi by the biochemical characteristics and 16S DNA sequencing. The culture solutions of the isolates adjusted to pH 7.0 showed H. pylori inhibition. The isolates grew well and H. pylori did not grow during the co-culture with those strains. Therefore, L. mesenteroides LAB kw5 and S. thermophilus LAB kw15 might be the candidates as the functional lactic acid bacteria for improving stomach health.

• Current Research on Agriculture and Life Sciences
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• v.7
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• pp.153-163
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• 1989

The activity changes and biochemical properties of ${\beta}$-gal in tomato fruits during ripening were investigated. The total activity was increased during ripening and three isoenzymes (${\beta}$-gal I, II and III) were purified through DEAE Sephadex A-50 and Sephadex G-100 column chromatography. The activities of ${\beta}$gal isoenzymes (${\beta}$-gal I, II and III) during ripening were 69.8, 31.8 and 170.0 units in mature green phase, while those were 48.7, 88.4 and 136.8 units in Red phase, respectively. As the ripening proceeded the activities of ${\beta}$-gal I and III were some what decreased but the activity of ${\beta}$-gal II was incresed more than 2.8 fold. The optimum pH of ${\beta}$-gal I, II and III were 3.9, 4.2 and 3.9 and the optimum temperature of those were $60^{\circ}C$, $56^{\circ}C$ and $60^{\circ}C$, respectively. All isoenzymes were stable at pH 3.6~6.0 and lost their activity about 50% when it heated at $55^{\circ}C$ for 5 minute. $Mg^{{+}{+}}$-activated the three isoenzymes but $Ca^{{+}{+}}$ and SDS inhibited about 30~40%. $Hg^{{+}{+}}$ inhibited completely. The km value of ${\beta}$-gal I, II and III was 0.36mM, 0.63mM and 0.45mM, reaction rate was rapidly increased until the concentration of substrate was $6.0{\times}10^{-5}M$.

• Journal of Mushroom
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• v.15 no.4
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• pp.249-253
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• 2017

Twelve strains of bacteria with cellulase and xylanase activities were isolated from spent mushroom substrates collected from button mushroom cultivation farm, Buye, Chungcheongnam-do in Korea. Among them, one strain, designated NO12, with higher cellulase and xylanase activities was selected by agar diffusion method. The strain NO12 was identified to be a Bacillus sp. by biochemical characteristics using Bacillus ID kit and MicroLog system. Comparative 16S rDNA gene sequence analysis showed that strain NO12 formed a distinct phylogenetic tree within the genus Bacillus and was most closely related to Bacillus subtilis with 16S rDNA gene sequence similarity of 99.2%. Based on its physiological properties, biochemical characteristics, and phylogenetic distinctiveness, strain NO12 was classified within the genus Bacillus, for which the name Bacillus subtilis NO12 was proposed. The cellulase and xylanase activities of B. subtilis NO12 were slightly increased according to bacterial population from exponential phase to stationary phase in the growth curve for B. subtilis NO12. The xylanase activity continuously increased from the beginning of the exponential phase and exhibited maximum activity in the middle of the exponential phase.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.176-182
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• 1999

Whole soybean cereal was fermented with four fungal strains (Mucor and Rhizopus) in pilot meju fermentation system. The pH range of the fermented soybean cereal was $7.16{\sim}8.38$, the contents of reducing sugar and amino-nitrogen were $0.54{\sim}2.64%,\;93{\sim}312mg%$, respectively, and that of free fatty acid ranged $0.06{\sim}2.00%$. The components of the amino acid, organic acid, free sugars and fatty acid showed distinctive patterns among four groups of fermented soybean cereals. Amylase activity and carbohydrate degradation rate of R. oryzae, protease and protein degadation rate of R. stolonifer was higher than other strains. But lipase and lipid degradation rates of four strains were similar. The odor concentrates of the soybean cereals fermented with Mucor strains were similar to Aspergillus strains, but Rhizopus were possessed of the flavor components of Bacillus and Aspergillus. Soysauce, made from M. hiemalis and R. stolonifer fermented soybean cereal showed excellent sensory evaluation and it was proposed that the two strains will be useful in Korean soysauce process.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.29 no.2
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• pp.25-35
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• 1997

오늘날 열대림 면적의 급격한 감소, 지구온난화등 지구환경 보전의 관점에서 이들 목재이외의 자원의 활용 및 양마와 같은 새로운 비목재자원 개발의 중요성이 재인식되기에 이르렀으며, 이 가운데서 양마는 생장이 라르고 수확량이 크며, 목질부의 단섬유는 물론 긴 섬유장을 가진 인피부섬유로 구성되어 있고, 실리카함량도 매우 적어, 특히 산림자원이 부족한 개발도상국에서 펄프.제지용 자원으로서 주목되고 있다. 양마가펄프.제지용자원으로서 오늘날과 같은 세계적 주목을 받게 된 것은 미국 농무성 북부지역연구센타 에서 이루어진 “새로운 섬유작물”에 관한 기초연구에서 양마가 제지용 섬유작물로서 높이 평가되고 있다. 양마의 경우 인피부는 비교적 리그닌함량이 적고, 목질부는 활엽수재에 가까운 리그닌을 함유하고 있는데다, 섬유형태에 있어서도 인피부와 목질부간에 큰 차이가 발견된다. 본 연구에서는 양마를 중성아황산법으로 전처리하여 제조한 반화학펄프로 부터 제조한 종이의 광학적 성질을 검토하였다 펄프의 광학적 성질은 원료의 화학적 조성,섬유의 형태, 부위.화학적 처리정도, 원료의 저장기간 및 충전제의 첨가에 따라 크게 영향을 받았다. 장섬유와 낮은 리그닌함량을 가진 전간부 펄프시트는 불투명도가 낮았으며, 목질부 펄프로부터 상대적으로 밀도가 다소 높고, 불투명도도 높은 종이를 만들 수 있었다. 펄프원료의 저장기간이 백색도를 낮추었으며, 불투명도에는 그다지 영향하지 않았다. 약품전처리 및 표백이 백색도 및 불투명도에 크게 영향하였고, 특히 충전제 첨가로 광산란을 증가시켜 불투명도가 높은 종이를 제조할 수 있었다.6. CL종의 난황콜레스테롤 수준에 대한 계란의 일령 상호간에는 전체적으로 상호간에 차이가 없었다. 7. 26주령시 혈중콜레스테롤 수준은 CL종이 다른 두 육계종들 보다 유의적 (P$\leq$0.05)으로 높았다. 8. 성별간 혈중콜레스테롤 수준의 차이는 CL종, BR1 및 BR2 중에서 CL종에서만 나타났으며, 수컷은 암킷보다 혈액 100 mL당 약 90 mg이 낮았다.구체적인 생화학적인 연구가 이루어져야 될 것으로 여겨진다.야 할 것으로 사료된다. 냉장 저장을 하고 저장기간이 길어질 경우는 냉동저장을 사용하는 것이 바람직하다고 생각된다.S, FOS나 말티톨로 대체된 스폰지 케익은 설탕 100% 사용한 케익과 비교하여 크게 나쁘지 않거나 휠씬 나은 특성을 보이므로 스폰지 케익 제조에 그들의 이용이 가능함을 확인하였다.thione 같은 다른 항산화제의 절약 효과, CYP2El의 유도 저하를 통하는 것으로 생각되며 그중 어떤 것에 가장 큰 영향을 받는 지는 아직 알려지지 않았고 더욱 많은 연구가 요구된다.우와 사료에 $\omega$3계 지방산 급원을 첨가, 동물에게 이행시켜 $\omega$3계 지방산 강화식품을 제조하는 두 가지 방법이 있을 수 있는데 전자는 통조림, 과자, 건강보조식품류에 다용되며 후자는 다양한 기능성 축산식품에 활용되고 있다. $\omega$3계 지방산 강화 축산식품에는 돼지고기, 우유, 치이즈, 계란, 분유, 햄 등 다양한 제품에 활용, 개발되고 있으며 최근에는 이러한 식품 개발에 더욱 박차가

• Microbiology and Biotechnology Letters
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• v.37 no.3
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• pp.183-188
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• 2009

Seven isolates showing strong proteolytic activity, KYC 1028, 1100, 1134, 1139, 1151, 1159, and 1182, were collected. Out of them, the broth of KYC 1134 and KYC 1139 showed the high proteolytic activity measured by azocazein. To determine 16S rDNA sequences for identification, 16S rDNA of seven isolates were amplified and compared with the 16S rDNA sequences of other myxobacteria at NCBI. It is evident from the phylo-genetic tree that the isolates belong to the genus Myxococcus. Sharing high percentage similarity values with myxobacteria, the 16S rDNA sequences were involved in two species, Myxococcus macrospores and M. Fulvus. Biochemical characteristics of KYC 1134 broth, which showed the highest proteolytic activity, showed increased activity 8 times to seven days after culture, and protein production were increased gradually and stopped at five days. The broth had optimal temperature at $60^{\circ}C$ for proteolytic activity, and stability of pH was ranged from pH 5 to 10, at $50^{\circ}C$ and 60, respectively. To classify proteases being in the broth, ten inhibitors were determined and only bestatin showed 27% inhibition effect. The inhibition result demonstrates that the broth contains kinds of amino peptidases and other exopeptidases.

• Journal of Wetlands Research
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• v.19 no.4
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• pp.375-382
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• 2017

In this study, general characteristics of dynamic behavior of stormwater runoff from a small impervious catchment was investigated from a series of simulations for a radial type surface runoff. Based on the simulation results, a better placement strategy for stormwater inlets to improve performance of a structural best management practice (BMP) was suggested. The degree of pollutant first flush from an ideal radial type impervious catchment was simulated using a 1-D diffusion wave equation coupled with a pollutant transport equation. The results showed that the first flush of the chemical oxygen demand was the strongest when the catchment length ranged 30-50m at a bed slope of 0.02. This result suggested that a required degree of the first flush can be intentionally obtained by just changing the locations and numbers of stormwater inlets, and thereby adjusting the catchment length. Particularly, the overall performance of a structural BMP in reducing pollutant load can be improved by placing the stormwater inlets at locations for obtaining a required first flush strength.