• 한국미생물·생명공학회지
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• 제50권3호
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• pp.319-327
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• 2022

γ-Aminobutyric acid (GABA) is a multi-functional compound with broad applications for food industry. GABA producing bacteria were isolated from cabbage kimchi. Among them, B737 was the best GABA producer when culture supernatants were analyzed by TLC. B737 was identified as Levilactobacillus brevis by 16S rRNA gene sequencing. Its glutamate decarboxylase (GAD) gene was cloned by PCR and the nucleotide sequence determined. B737 GAD consisting of 485 amino acids is the largest in size among GADs reported from LAB so far. gadB from L. brevis B737 was overexpressed in Escherichia. coli BL21(DE3) using pET26b(+).pET26b(+). The recombinant GAD was purified and its size was 55 kDa by SDS-PAGE. Maximum GAD activity was observed at pH 5 and 40℃ and the activity was dependent on pyridoxal 5'-phosphate. K_m and V_max of recombinant GAD were 6.2 ± 0.06 mM and 0.34 ± 0.002 mM/min, respectively. L. brevis B737 can be used as a starter for fermented foods with high GABA contents.

• 한국환경생태학회지
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• 제24권2호
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• pp.117-129
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• 2010

태안해안국립공원 15개소 일대의 관속식물은 117과 326속 436종 49변종 6품종 2교잡종으로 총 493분류군이 확인되었다. 태안해안국립공원은 해안과 주변의 섬을 포함하고 있는 지역으로 남부지역에 주로 분포하는 천선과나무, 후박나무, 참식나무 및 사스레피나무 등과 해안사구지역에 주로 분포하는 해당화, 통보리사초 및 갯그령이 나타났다. 그리고 단풍나무, 사철나무 및 동백나무 등 낙엽활엽수와 상록활엽수가 혼합되어 분포하고 있어서 해안이라는 지역적인 특징과 중부아구와 남부아구의 점이지대로서의 특징을 잘 반영하고 있다고 볼 수 있다. 환경부 지정 멸종위기종은 확인되지 않았으며, 식물구계학적 특정식물종은 총 53종으로 I 등급에 해당하는 종은 순비기나무, 두루미천남성 및 큰천남성 등으로 41종이 확인되었고, II 등급에 해당하는 종은 꽃창포 1종이 확인되었으며, III 등급에 해당하는 종은 모감주나무, 솔장다리 및 굴거리나무 등으로 7종이 확인되었고, IV 등급에 갯강활 1종, V 등급에 통발 1종이 확인되었다. 귀화식물은 도깨비가지, 미국자리공 및 달맞이꽃 등 17과 44속 51종 1품종으로 총 52분류군이 확인되었다. 이 중 생태계교란야생 동 식물로 알려진 도깨비가지, 서양금혼초와 양미역취 등 3종은 물리적 제거와 같은 관리가 요망된다.

• 미생물학회지
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• 제42권2호
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• pp.160-163
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• 2006

현미는 백미에 비하여 식품영양학적 가치 및 식이섬유의 함유량이 높은 쌀겨 및 배아를 포함하고 있으나 소화가 잘되지 않는 단점 이 있다. 따라서 발효현미는 소화력을 높임과 동시에 좋은 영양 공급원이 될 수 있으므로 높은 amylase와 pretense의 활성으로 현미를 발효할 수 있는 미생물을 선별하였다. 2.5%(w/v)의 현미분말을 유일한 영양원으로 한 액체배지를 생장배지로 사용하여 생장능력과 효소 생산능력을 조사하였다. 조사한 8종의 Bacillus 와 11종의 유산균 중에서 모든 Bacillus 균주와 두 종의 유산균이 생장과 효소활성을 보였다. 생균수는 $10^7CFU/mL$을 초과하였으며 Bacillus sp. Bacillus sp. B2, Bacillus sp. B11, Leuconostoc gelidum, Pediococcus pentosaceus 가 생산하는 최고 amylase 활성은 각각 17.85, 17.50, 17.10, 17.10, 3.24 U/ml이었고, 최고 pretense 활성은 각각 22.48, 22.04, 23.76, 12.13, 3.80 U/ml이었다. 따라서 이 균주들은 발효 현미 제조를 위한 접종균주로서 이용이 가능하리라 사료된다.

• 한국가축번식학회지
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• 제25권2호
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• pp.163-169
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• 2001

본 연구는 마우스 정자-난자 결합분석 법(oocytes-sperm binding assay; OSBA)을 이용하여 단백질원, 배양액의 질, 난자의 성숙도에 따라서 정자와 난자의 결합능력을 알아보고 그 유용성을 알아보기 위하여 실시하였다. 4~5주령의 hybrid(C57BL/6 $\times$ CBA/N) F$_1$ 암컷에서 회수된 미수정란에 0.1% hyaluronidase를 이용하여 난구세포를 제거하였으며, 제1극체의 존재유무에 따라 Met. II(mature)와 Met. I(intermediate mature)로 구분하였다. 암컷과 동일 계통의 8주령 이상 된 수컷에서 회수된 정소상체 미부정자를 37$^{\circ}C$에서 10분간 배양하였다. 배양된 정자부유액은 단백원 무첨가배양액과 1:5로 희석하여 10분간 배양한 다음 3 ${\mu}\ell$를 10$\pm$2개의 난자를 들어있는 배양액 소적(30 ${\mu}\ell$)에 넣어서 정자와 난자의 결합을 유도하였다. 정자 주입 후 3시간 혹은 24시간째에 난자를 뽑아내어 세척하였으며, 도립현미경(100$\times$)에서 난자에 부착된 정자의 수를 세었다. 수정란을 이용한 정도관리를 위하여 과배란이 유도된 암컷은 수컷과 합사시켰으며, hCG 주사 16~18시간째에 전핵기의 1세포 수정란을 회수하였다. 단백질원의 종류에 대한 효과를 확인하기 위하여 OSBA를 실시한 결과, 수정 3시간째에 난자당 하나 이상의 정자가 부착된 난자의 비율은 BSA첨가군, 무첨가군, FBS 첨가군의 순으로 유의한 차이를 나타내었다(100% vs. 60.2% vs. 2.1%). 한편, BSA 첨가군에서 정자의 결합능력이 우수하였으나 FBS는 매우 유해하였으며 FBS의 농도가 5%까지는 증가함에 따라 유의한 차이를 나타내었다. 따라서 투명대에 정자가 부착에 있어서 단백원이 매우 중요한 역할을 하며, OSBA는 정자와 난자의 결합에 결정적인 영향을 미칠 수 있는 배양조건을 명확히 판별할 수 있음을 시사하였다. Met. II(mature)와 Met. I(intermediate mature) 난자를 단백원 무첨가, 15% FBS, 0.4% BSA 및 10% AF(양수)가 첨가된 Ham's F-10 배양액에서 OSBA를 실시한 결과, 난자의 성숙도에 상관없이 정자의 결합능력은 비슷한 양상을 보였으며, BSA첨가군, 양수첨가군, 무첨가군, FBS첨가군 순으로 높게 나타났다. 이러한 결과는 OSBA에서 Met. II 난자 대신에 Met. I난자를 이용해도 비슷한 결과를 얻을 수 있음을 시사한다. 생쥐 1세포기배에서 배반포까지의 배발달율을 기준으로 Ham's F-10배양액을 평가하여 일련번호 151은 불량(poor), 152는 양호(good)로 판정한 다음, 동일한 배양액에 OSBA를 실시한 결과 생쥐 1세포기배의 결과와 마찬가지로 일련번호 152 배양액이 151 배양액보다 유의하게 높게 나타났다. 따라서 OSBA는 기존의 정도관리 방법과 동일한 효과를 기대할 수 있을 것이다. 결론적으로, OSBA는 배양액 조건에 따라 정자의 결합능력이 다르다는 것을 보여주었으며, 정토관리 방법으로서의 유용성을 확인시켜 주었다. 또한 쉽게 준비할 수 있는 생쥐의 난자와 정자를 이용하였으며, 배양시간이 3시간으로 짧고, 평가방법이 간편해 시간적, 경제적으로도 효율성이 높다고 사료된다.

• Journal of Microbiology and Biotechnology
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• 제26권1호
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• pp.9-19
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• 2016

Xylanases sourced from different bacteria have significantly different enzymatic properties. Therefore, studying xylanases from different bacteria is important to their applications in different fields. A potential xylanase degradation gene in Massilia was recently discovered through genomic sequencing. However, its xylanase activity remains unexplored. This paper is the first to report a xylanase (XynRBM26) belonging to the glycosyl hydrolase family (GH10) from the genus Massilia. The gene encodes a 383-residue polypeptide (XynRBM26) with the highest identity of 62% with the endoxylanase from uncultured bacterium BLR13. The XynRBM26 expressed in Escherichia coli BL21 is a monomer with a molecular mass of 45.0 kDa. According to enzymatic characteristic analysis, pH 5.5 is the most appropriate for XynRBM26, which could maintain more than 90% activity between pH 5.0 and 8.0. Moreover, XynRBM26 is stable at 37℃ and could maintain at least 96% activity after being placed at 37℃ for 1 h. This paper is the first to report that GH10 xylanase in an animal gastrointestinal tract (GIT) has salt tolerance, which could maintain 86% activity in 5 M NaCl. Under the optimum conditions, K_m, V_max, and k_cat of XynRBM26 to beechwood xylan are 9.49 mg/ml, 65.79 μmol/min/mg, and 47.34 /sec, respectively. Considering that XynRBM26 comes from an animal GIT, this xylanase has potential application in feedstuff. Moreover, XynRBM26 is applicable to high-salt food and seafood processing, as well as other high-salt environmental biotechnological fields, because of its high catalytic activity in high-concentration NaCl.

• 대한약침학회지
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• 제7권3호
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• pp.77-88
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• 2004

Objectives ; This study was to investigate the anti-cancer effects of herbal acupuncture with distilled fresh ginseng. The herbal acupuncture was injected to Chung-wan($C.V_{12}$) and Wisu($BL_{21}$) of mice that were subjected to Sarcoma-180 adbominal cancer cell and A549 human epithelial lung cancer cells in vitro. Methods : Anti-cancer effects of distilled fresh ginseng herbal acupuncture were tested by measruing Cox, Bcl-2, and Bax by using RT-PCR in A549 human epithelial lung cancer cells in vitro. And four weeks old Balb/c line male mice weighing around $20\;{\pm}\;3g$ were used to measure survival rate and anti-cancer effect to outputs of interleukin-2 and interleukin-4 using flow cytometry, possibility of mRNA menifestation using RT-PCR, and Cox mRNA. The results are as follows. Results : 1. In measuring mRNA menifestation in Cox, Bcl-2, and Bax by using RT-PCR in A549 human epithelial lung cancer cells in vitro, the result showed that fresh ginseng decreased Cox-2 which is directly involved in Inflammation process. 2. Survival rate was measured in an anti-cancer effect experiment against Sarcoma-180 abdorminal cancer. Median survival time of controlled group was 27 days, of experiment group I was 21 days, and of experiment group II was 27 days. Therefore, experiment group I showed -22.2% increase in survival rate and experiment group II showed no difference compare to controlled group. 3. There was no difference between condition group and controlled and experiment group in measuring outputs of interleukin-2 and interleukin 4 by using flow cytometry 4. In measuring outputs of interleukin-2 by using ELISA, there was no significant difference between condition group and controlled group and there was decrease in experiment group II compared to conditioned and controlled group. 5. In measuring cytokine mRNA menifestation by using RT-PCR, experiment group I showed increase of mRNA menifestation in interleukin-2,4 and $interferon-{\gamma}$ and experiment group II showed no significant difference in $interferon-{\gamma}$. Conclusion : According to the results, fresh ginseng herbal-acupuncture took a little effects in cancer. In using distilled fresh ginseng herbal acupuncture has effect on Cox-2 decrease. However, the difference in concentration of fresh ginseng showed no effect on killing cancer cell. It is assumed that inaccurate concentration of herbal acupuncture and fresh ginseng component could be the reason for this result. Therefore, future consideration will be studies on herbal acupuncture concentration.

• 한국식품위생안전성학회지
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• 제32권1호
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• pp.50-56
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• 2017

본 연구는 약수와 약수터 음용도구의 일반세균수, 대장균군수 및 식중독세균 오염도를 평가하여 약수와 음용도구의 미생물학적 안전성을 평가하고자 하였다. 약수터 10곳의 약수와 약수터에 비치되어 있는 음용도구 34건을 실험대상으로 하였다. 약수의 경우 일반세균수는 평균 1.8 log CFU/mL 검출되었고 음용도구의 경우 평균 $4.7log\;CFU/100cm^2$ 검출되었다. 위생지표미생물인 대장균군의 경우 약수는 평균 1.2 log CFU/mL 검출되었고 음용도구는 평균 $1.7log\;CFU/100cm^2$ 검출되었다. B. cereus, S. aureus, Salmonella spp., E. coli O157:H7, L. monocytogenes, V. parahaemolyticus, Y. enterocolitica를 실험한 결과 약수와 음용도구에서 Y. enterocolitica 등 6종의 식중독 미생물은 검출되지 않았으나, B. cereus는 음용 도구 34건 중 5건 (14.7%) 검출되었다. 약수터 음용도구에서 분리된 B. cereus의 주요 설사독소 유전자는 nheA와 entFM로 나타났다. B. cereus 5균주는 모두 NHE 설사 독소를 생산하였으나 HBL은 2균주에서만 검출되었다. 항생제 감수성 실험결과 oxacillin 등 ${\beta}-lactam$계 항생제에 내성을 나타내었다. 약수터 음용도구의 미생물 오염도와 분리된 B. cereus의 독소 유전자 및 독소 단백질 생산능을 분석한 결과 약수터에 비치된 음용도구에 의한 식중독 위험성이 상존하는 것으로 나타났다. 따라서 다중이 사용하는 약수터 음용도구의 철저한 위생관리가 필요하며 위생관리가 곤란할 경우 개인 컵을 이용하거나 미생물 안전성을 확보할 수 있는 음용도구 개발이 필요한 것으로 판단되었다.

• 한국산업융합학회 논문집
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• 제21권3호
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• pp.141-147
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• 2018

In a time when product development cycles are getting shorter and shorter, many companies are making efforts to develop products with high reliability in a short period of time, accelerated life test is widely used as a method to quickly evaluate reliability. Accelerated life test reduces the test life or the life of the product from the observed data by shortening the lifetime of the product or abruptly lowering the performance under the worse condition than the actual condition in order to shorten the test cost or the test time. In this paper, BL3640A-06P+RB35, DC12V model, which is used in the support device of an automatic rotation type digital signage, which display various information such as textures and images on a display screen in a public place or a commercial space, BLDC motors were subjected to a constant stress test and at the rotational speed of 1rpm, $180^{\circ}$ rotation and reverse rotation under actual use conditions, the stress was imposed on the rotating speed of 2rpm and the weight of the actual installed product from 22.2kgf to 10kgf were installed. The lifetime of the actual use environment condition is 23,545 hours and the rotation speed is accelerated. The life time of the acceleration condition with the additional weight is 1,380 hours. The acceleration factor is calculated as 17.06, the one year guarantee test day is 235 days to 14 days, of the period from 470 days to 28 days, and the third year from 704 days to 42 days. The test date of the BLDC motor was tested on the shortened test date, and the rotational speed and the current value were measured. It is found that there is no defect even if it operates as the test date corresponding to the specified one year warranty period and the 3 year accelerated life test which is experimented. Using the statistical technique of the regression analysis the expected time for the motor to defect to #4 samples was 20 years.

• Journal of Microbiology and Biotechnology
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• 제28권4호
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• pp.606-612
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• 2018

The enzyme xylose isomerase (E.C. 5.3.1.5, XI) is responsible for the conversion of an aldose to ketose, especially xylose to xylulose. Owing to the ability of XI to isomerize glucose to fructose, this enzyme is used in the food industry to prepare high-fructose corn syrup. Therefore, we studied the characteristics of XI from Anoxybacillus kamchatkensis G10, a thermophilic bacterium. First, the gene coding for XI (xylA) was inserted into the pET-21a(+) expression vector and the construct was transformed into the Escherichia coli competent cell BL21 (DE3). The expression of recombinant XI was induced in the absence of isopropyl-thio-${\beta}$-galactopyranoside and purified using Ni-NTA affinity chromatography. The optimum temperature of recombinant XI was $80^{\circ}C$ and measurement of the heat stability indicated that 55% of residual activity was maintained after 2 h incubation at $60^{\circ}C$. The optimum pH was found to be 7.5 in sodium phosphate buffer. Magnesium, manganese, and cobalt ions were found to increase the enzyme activity; manganese was the most effective. Additionally, recombinant XI was resistant to the presence of $Ca^{2+}$ and $Zn^{2+}$ ions. The kinetic properties, $K_m$ and $V_{max}$, were calculated as 81.44 mM and $2.237{\mu}mol/min/mg$, respectively. Through redundancy analysis, XI of A. kamchatkensis G10 was classified into a family containing type II XIs produced by the genera Geobacillus, Bacillus, and Thermotoga. These results suggested that the thermostable nature of XI of A. kamchatkensis G10 may be advantageous in industrial applications and food processing.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.407-410
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• 2002

Monochromatic x-ray CT has several advantages over conventional CT, which utilizes bremsstrahlung white x-rays from an x-ray tube. There are several methods to produce such monochromatic x-rays. The most popular one is crystal diffraction monochromatization, which has been commonly used because of the fact that the energy spread is very narrow and the energy can be changed continuously. The alternative method is the use of fluorescent x-ray, which has several advantages such as large beam size and fast energy change. We have developed a parallel-beam and a fan-beam monochromatic x-ray CT, and compared some characteristics such as accuracy of CT numbers between those systems. The fan beam monochromatic x-rays were generated by irradiating target materials by incident white x-rays from a bending magnet beam line NE5 in 6.5 GeV Accumulation Ring at Tukuba. The parallel beam monochromatic x-rays were generated by using a silicon double crystal monochromator at the bending magnet beam line BL-20BM in Spring-8. A Cadmium telluride (CdTe) 256 channel array detector with 512mm sensitive width capable of operating at room temperature was used in the photon counting mode. A cylindrical phantom containing eight concentrations of gadolinium was used for the fan beam monochromatic x-ray CT system, while a phantom containing acetone, ethanol, acrylic and water was used for the parallel monochromatic x-ray CT system. The linear attenuation coefficients obtained from CT numbers of those monochromatic x-ray CT images were compared with theoretical values. They showed a good agreement within 3%. It was found that the quantitative measurement can be possible by using the fan beam monochromatic x-ray CT system as well as a parallel beam monochromatic X-ray CT system.