• Journal of Microbiology and Biotechnology
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• 제20권2호
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• pp.301-310
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• 2010

Bacillus subtilis strains produce a broad spectrum of bioactive peptides. The lipopeptide surfactin belongs to one well-known class, which includes amphiphilic membrane-active biosurfactants and peptide antibiotics. Both the srfA promoter and the ComP-ComA signal transduction system are an important part of the factor that results in the production of surfactin. Bs-M49, obtained by means of low-energy ion implantation in wild-type Bs-916, produced significantly lower levels of surfactin, and had no obvious effects against R. solani. Occasionally, we found strain Bs-M49 decreased spore formation and the development of competence. Blast comparison of the sequences from Bs-916 and M49 indicate that there is no difference in the srfA operon promoter PsrfA, but there are differences in the coding sequence of the comA gene. These differences result in three missense mutations within the M49 ComA protein. RT-PCR analyses results showed that the expression levels of selected genes involved in competence and sporulation in both the wild-type Bs-916 and mutant M49 strains were significantly different. When we integrated the comA ORF into the chromosome of M49 at the amyE locus, M49 restored hemolytic activity and antifungal activity. Then, HPLC analyses results also showed the comA-complemented strain had a similar ability to produce surf actin with wild-type strain Bs-916. These data suggested that the mutation of three key amino acids in ComA greatly affected the biological activity of Bacillus subtilis. ComA protein 3D structure prediction and motif search prediction indicated that ComA has two obvious motifs common to response regulator proteins, which are the N-terminal response regulator receiver motif and the C-terminal helix-turn-helix motif. The three residues in the ComA N-terminal portion may be involved in phosphorylation activation mechanism. These structural prediction results implicate that three mutated residues in the ComA protein may play an important role in the formation of a salt-bridge to the phosphoryl group keeping active conformation to subsequent regulation of the expression of downstream genes.

• 식물분류학회지
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• 제36권3호
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• pp.189-207
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• 2006

로젯사철란(G. rosulacea Y. Lee)은 애기사철란과 유사하나 로젯트형의 잎, 짧은 땅속줄기와 서식지 등의 특징에 의해 한국산 사철란속(Goodyera R. Br.) 내의 신종으로 기재된 바 있다. 로젯사철란의 분류군의 실체와 근연종간의 유연관계를 파악하기 위하여 군외군을 포함한 24개의 사철난속 식물을 대상으로 핵 리보좀(ribosomal)의 DNA internal transcribed spacer와 엽록체 DNA의 trnL 구간의 염기서열을 분석하였다. 분류군의 실체와 근연종간의 유연관계는 정렬된 염기서열을 바탕으로 최대절약분석(Maximum parsimony analysis)와 근연결합법(Neibour Joining method)에 의한 계통수 및 고유 표지유전자 여부로 추정하였다. 분석 결과 로젯사철란은 다수의 고유한 표지유전자를 가지며, ITS와 trnL 계통수에서 모두 단계통군을 형성하였다. 로젯사철란과 한국산 사철란속 내 각 분류군간의 유전적 거리(pairwise distance)는 ITS에서 3.49-6.68, trnL에서 5.05-9.53으로서 독립된 종으로 간주하기에 무리가 없었다. 따라서 분자적 결과는 로젯사철란을 사철란속내 독립된 종으로 처리하는 것을 지지하였다. 계통수에서 로젯사철란은 형태적으로 유사한 애기사철란(G. repens)과 동일한 분계조를 형성하였고, 유전적 거리도 조사한 분류군들 중 가장 낮은 값을 나타냈으므로 가장 가까운 근연분류군임을 나타내었다.

• 한국균학회지
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• 제20권2호
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• pp.118-125
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• 1992

노랑느타리 Pleuroltus cornucopiae와 사철느타리 Pleurolus florida의 영양요구주(營養要求株)로부터 나출(裸出)한 원형질체(原形質體)를 polyethylene glycol로 융합(融合)하여 종간(種間) 체세포잡종(體細胞雜種)을 얻었다. 이들은 핵융합주(核融合株) nuclear hybrid 또는 이질이배체(異質二倍體) allodiploid, 이핵체(異核體) heterokaryon, 자연적(自然的) 분리성이핵체(分離性異核體) spontaneous segregated heterokaryon로 나누어졌으며, 6융합조합(融合組合)중에서 1조합(組合)에서만 꺽쇠연결체 clamp connection를 가진 것이 나타났다. 총 59 융합주 중에서 꺽쇠연결체를 가진 2균주와 가지지 않은 10균주가 완전한 자실체(子實體)를 형성하였는데 거의 사철느타리 형태(形態)와 유사(有似)하였으나 버섯의 갓 색택(色澤)이 양친(兩親)인 노랑느타리가 어릴때 yellow, 사철느타리가 orange white 인데비해 체세포 잡종은 light blond-greyish brown 으로 다양한 혼합색(混合色)으로 나타났다. 꺽쇠연결체가 없는 융합주로부터 발용(發茸)된 자실체는 두균주를 제외하고 모두 꺽쇠연결체를 가졌으며, 이 자실체(子實體) 조직(組織)을 완전배지(完全培地)에 배양(培養)한 결과 균사생장(菌絲生長)이 빠르고 균사도 꺽쇠연결체를 가져 본래(本來)의 융합주와는 다른 형태로 변하였다.

• 한방안이비인후피부과학회지
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• 제24권1호
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• pp.121-141
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• 2011

Objective : This Experimental study was done to investigate the Effect of Taklisodok-um and Hwangryunhaedok-tang(TH) on Atopic Dermatitis. Methods : We assessed effects of TH on the IgE, IL-4, IL-5, IL-6, IgM, IgG1, IFN-${\gamma}$ in vivo, on the IL-4, IL-5, CCR3 in the skin tissues of ear and dorsum with NC/Nga mice. And we assessed effects of TH on the COX-2, IL-$1{\beta}$, TNF-${\alpha}$, IL-6 with RAW 264.7 cell. Results and Conclusion : 1. IgE, IL-4, IL-5, IL-6, IgM, IgGl levels in the serum of TH treated NC/Nga mouse group were decreased compared to the untreated control mice. IFN-r showed a increase in the experimental group compared to the untreated control group. The spleen weight of TH treated NC/Nga mice was decreased compared to the untreated control group. 2. mRNA expression levels of IL-4, IL-5 and CCR3 in the skin tissues of TH treated NC/Nga mice were decreased, and expression levels of IL-6 in the skin tissues of TH treated NC/Nga mice were decreased compared to the untreated control group. IFN-${\gamma}$ mRNA expression levels were increased compared to the untreated control group. 3. Judged from that IL-$1{\beta}$, TNF-${\alpha}$, IL-6 express of gene, effect of inflammatory Cytokines revelation were decreased compared to the untreated control group. 4. Depend on the strength of TH, inflammatory RAW 264.7 in the serum of TH were inhibited compared to the untreated control serum that leaded a COX-2 activity model. 5. Histological observation of the ear and skin tissues showed that the extents of inflammation and infiltrated immune cells in the epidermis and dermis of TH treated NC/Nga mice were highly reduced compared to the untreated control group.

• 미생물학회지
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• 제51권4호
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• pp.347-354
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• 2015

콩은 우리나라와 극동아시아가 원산지로 알려져 있으나 국산 콩의 근권 세균 군집에 대한 연구는 미흡하다. 따라서 본 연구에서는 국산 재배콩을 대상으로 차세대 염기서열 분석 방법인 파이로시퀀싱 방법을 사용하여 콩 근권 세균 군집 구조를 해석하고 생육단계별 군집의 변화 및 콩 근권의 핵심 세균 군집을 구명하고자 하였다. 세균 군집 분석 결과, 근권 세균의 군집은 근권과 비근권간에 뚜렷한 차이를 보였으며, 총 21개의 문으로 구성되었다. Proteobacteria가 가장 우점(36.6-42.5%)하였고, Acidobacteria (8.6-9.4%), Bacteroidetes (6.1-10.9%), Actinobacteria (6.4-9.8%), Firmicutes (5.7-6.3%) 등의 순으로 상대풍부도가 감소하였다. 모든 생육단계에 걸쳐 콩 근권의 핵심 세균 군집에는 Proteobacteria에 속한 OTU들이 가장 많이 분포하였으며, 이들 중 Bradyrhizobium에 속한 OTU의 상대 풍부도가 가장 높았다. 본 연구결과는 콩 근권의 핵심 세균 군집은 주로 생육 촉진 기능과 유기물 순환에 관련된 OTU로 구성되어 있다는 것을 보여주었다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권18호
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• pp.8281-8285
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• 2016

Background: Helicobacter pylori is a cause of chronic gastritis, peptic ulcer disease, and gastric malignancy, infection being a serious health problem in Thailand. Recently, clarithromycin resistant H. pylori strains represent the main cause of treatment failure. Therefore this study aimed to determine the prevalence and pattern of H. pylori resistance to clarithromycin in Suranaree University of Technology Hospital, Suranree University of Technology, Nakhon Ratchasima, Northeastern Thailand, Nakhon Ratchasima province, northeast of Thailand. Materials and Methods: This hospital-based cross-sectional study was carried out between June 2014 and February 2015 with 300 infected patients interviewed and from whom gastric mucosa specimens were collected and proven positive by histology. The gastric mucosa specimens were tested for H. pylori and clarithromycin resistance by 23S ribosomal RNA point mutations analysis using real-time polymerase chain reactions. Correlation of eradication rates with patterns of mutation were analyzed by chi-square test. Results: Of 300 infected patients, the majority were aged between 47-61 years (31.6%), female (52.3%), with monthly income between 10,000-15,000 Baht (57%), and had a history of alcohol drinking (59.3%). Patient symptoms were abdominal pain (48.6%), followed by iron deficiency anemia (35.3%). Papaya salad consumption (40.3%) was a possible risk factor for H. pylori infection. The prevalence of H. pylori strains resistant to clarithromycin was 76.2%. Among clarithromycin-resistant strains tested, all were due to the A2144G point mutation in the 23S rRNA gene. Among mutations group, wild type genotype, mutant strain mixed wild type and mutant genotype were 23.8%, 35.7% and 40.5% respectively. With the clarithromycin-based triple therapy regimen, the efficacy decreased by 70% for H. pylori eradication (P<0.01). Conclusions: Recent results indicate a high rate of H. pylori resistance to clarithromycin. Mixed of wild type and mutant genotype is the most common mutant genotype in Nakhon Ratchasima province, therefore the use of clarithromycin-based triple therapy an not advisable as an empiric first-line regimen for H. pylori eradication in northeast region of Thailand.

• 미생물학회지
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• 제53권3호
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• pp.180-192
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• 2017

본 연구에서는 깍두기로부터 분리한 유산균으로 발효시킨 사워도우의 항산화 및 항균 활성을 조사하였다. 염기서열 분석을 통해 분리 균주는 99%의 상동성을 가진 Leuconostoc dextranicum SRK03, Lactobacillus brevis SRK15, Pediococcus halophilus SRK22, Lactobacillus acidophilus SRK30, Lactobacillus plantarum SRK38, Leuconostoc citreum SRK 42 및 Lactobacillus delbrueckii SRK60으로 동정되었다. L. dextranicum SRK03, L. acidophilus SRK30, L. plantarum SRK38 혹은 L. delbreckii SRK60과 Saccharomyces cerevisiae KCTC 7246을 혼합하여 $30^{\circ}C$에서 24시간 발효시킨 사워도우의 유산균과 효모수는 각각 $10^9$ 및 $10^7CFU/g$이었으며, 특히 L. dextranicum SRK03으로 제조한 사워도우는 L. acidophilus SRK30, L. plantarum SRK38 및 L. delbreckii SRK60 보다 유의하게 높은 총 산도와 에탄올 및 세포 외 다당류 함량을 나타내었다. L. dextranicum SRK03 및 L. acidophilus SRK30으로 제조한 사워도우는 DPPH 라디칼 소거능과 유지의 과산화 억제능도 높았다. 게다가 L. acidophilus SRK30이 생산한 유기산과 박테리오신에 의해 $25^{\circ}C$에서 5일간 저장하는 동안 사워도우 내 Bacillus cereus ATCC 11778과 Staphylococcus aureus ATCC 6538의 균수는 유의하게 낮은 수준을 유지되었다.

• 한국환경보건학회지
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• 제40권2호
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• pp.88-97
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• 2014

Objectives: The aim of this study was to evaluate the occurrence of microbiological contamination of kitchen utensils and environments of food service operations at university located in Seoul, Korea. Methods: We collected swab samples from the surfaces of knives, chopping boards, floors, and drains, as well as drinking water and airborne bacteria samples from 20 food service operations. Three bacterial indicators and five food poisoning bacteria were measured quantitatively and qualitatively, respectively. We used selective culture media and the PCR assay targeting 16S rRNA gene for the microbiological analysis. Results: We detected bacterial indicators on knives or chopping boards in eight different food service operations and, three food service operations (I, M, and O) showed more than 3 log colony forming units $(CFU)/100cm^2$ on their knives, significantly higher than the others. The levels of bacterial indicators on the floors and drains in the cooking areas were much higher than those on the cooking utensils. S. aureus was detected on 10 floors and 8 drains. Culturable bacteria were identified in 5 drinking water samples, and food service operation B ($431.1CFU/m^3$) and C ($551.2CFU/m^3$) showed more than $400CFU/m^3$ of total airborne bacteria. Conclusions: These results suggest that some of food service operations in this study may require additional investigation to secure the microbial safety of cooking environments. In addition, further actions including hygiene education for employees and proper guidelines to maintain clean cooking environments should be prepared.

• 한국환경과학회지
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• 제25권6호
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• pp.789-798
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• 2016

Lactic acid bacteria (LAB) are industrially important microorganisms for probiotics. The recent widespread application of LAB for preparation of functional food is attributable to the accumulating scientific evidence showing their beneficial effects on human health. In this study, we isolated and characterized plant-derived LAB that show angiotensin-converting enzyme (ACE) inhibitory and antioxidant activities. The selected strain K2 was isolated from Kimchi, and identified as Lactobacillus plantarum by 16S rRNA gene analysis. The strain grew under static and shaking culture systems. They were also able to grow in different culture conditions like $25^{\circ}C{\sim}37^{\circ}C$ temperature, 4~10 pH range and ~6% NaCl concentration. L. plantarum K2 was highly resistant to acid stress; survival rate of the strain at pH 2.5 and 3 were 80% and 91.6%, respectively. The strain K2 also showed high bile resistance to 0.3% bile bovine and 0.3% bile extract with more than 74% of survival rate. The cell grown on MRS agar plate containing bile extract formed opaque precipitate zones around the colonies, indicating they have bile salt hydrolase activity. The strain showed an inhibitory activity against pathogenic bacteria such as Escherichia coli, Staphylococcus aureus and Listeria monocytogenes; antibacterial activity was probably due to the lactic acid. The K2 strain showed relatively higher autoaggregation values, antihypertensive and antioxidant activities. These results suggest that L. plantarum K2 could be not only applied as a pharmabiotic for human health but also is also starter culture applicable to fermentative products.

• Journal of Periodontal and Implant Science
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• 제41권5호
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• pp.218-226
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• 2011

Purpose: Micro-computed tomography (micro-CT) has been widely used in the evaluation of regenerated bone tissue but the reliability of micro-CT has not yet been established. This study evaluated the correlation between histomorphometric analysis and micro-CT analysis in performing new bone formation measurement. Methods: Critical-size calvarial defects were created using a 8 mm trephine bur in a total of 24 Sprague-Dawley rats, and collagen gel mixed with autogenous rat bone marrow stromal cells (BMSCs) or autogenous rat BMSCs transduced by adenovirus containing bone morphogenic protein-2 (BMP-2) genes was loaded into the defect site. In the control group, collagen gel alone was loaded into the defect. After 2 and 4 weeks, the animals were euthanized and calvaria containing defects were harvested. Micro-CT analysis and histomorphometric analysis of each sample were accomplished and the statistical evaluation about the correlation between both analyses was performed. Results: New bone formation of the BMP-2 group was greater than that of the other groups at 2 and 4 weeks in both histomorphometric analysis and micro-CT analysis (P=0.026, P=0.034). Histomorphometric analysis of representative sections showed similar results to histomorphometric analysis with a mean value of 3 sections. Measurement of new bone formation was highly correlated between histomorphometric analysis and micro-CT analysis, especially at the low lower threshold level at 2 weeks (adjusted $r^2=0.907$, P<0.001). New bone formation of the BMP-2 group analyzed by micro-CT tended to decline sharply with an increasing lower threshold level, and it was statistically significant (P<0.001). Conclusions: Both histomorphometric analysis and micro-CT analysis were valid methods for measurement of the new bone in rat calvarial defects and the ability to detect the new bone in micro-CT analysis was highly influenced by the threshold level in the BMP-2 group at early stage.