• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.125-128
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• 2000

본 연구에서는 순환식 돈분 폐수 처리 시스템에서의 미생물 분포에 따른 폐수 처리 효과를 모델링하기 위해 신경회로망과 PCA를 이용하는 새로운 방법을 제안하였다. PCA 분석 결과를 바탕으로 신경회로망의 최적 입력 조건을 찾고, 실측 데이터를 이용하여, 폐수 처리 시스템의 각 탱크를 별도로 학습함으로써 비교적 적은 수의 데이터에도 불구하고 정확한 모델링 결과를 얻었다. 제안한 시스템은 폐수 처리 시스템의 효과적인모니터링 시스템으로 사용할 수 있으며, 향후 실제 돈분 처리 시스템에서 원하는 기준의 방류수를 얻기 위한 최적의 입력조건 (미생물밀도 등)을 결정하는데 있어서 에뮬레이터로 사용될 수 있을 것으로 기대된다.

• Applied Biological Chemistry
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• 제9권
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• pp.35-39
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• 1968

오이 성분(成分)이 유산균(乳酸菌) 생육(生育)에 미치는 영향(影響)과 이로인(因)한 김치의 한숙현상(旱熟現象)을 연구(硏究)하여 다음 결과(結果)를 얻었다. 1) 김치의 조성재료(組成材料)로 1%의 오이를 첨가(添加)하므로서 김치 발효(醱酵)의 lagphase를 현저히 단축(短縮)시켜 발효(醱酵)를 촉진(促進)하는 한중현상(旱中現象)을 보였다. 2) Cucumber serum 중(中)에서 alcohol-soluble fraction은 Lactobacillus plantarum에 대(對)하여 생육촉진(生育促進) 효과(？果)를 보였으나 Streptococcus faecalis의 생육(生育)에는 영향(影響)이 없었다. 3) Alcohol-soluble fraction의 효과는 투석(透析) 및 $120^{\circ}C$, 10 분간(分間)의 열처리(熱處理)에 의(依)하여 실활(失活)되었다. 오이 조직(組織)의 물리적성질(物理的性質)에 따른 내용성분(內容成分)의 용출정도(溶出程度)를 관찰(觀察)하여 생육(生育) 및 생산촉진요인(生産促進要因)을 물리화학적면(物理化學的面)에서 고찰(考察)하였다.

• 한국미생물·생명공학회지
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• 제29권1호
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• pp.1-11
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• 2001

Lactic acid bacteria (LAB) are widely used for various food fermentation. With the recent advances in modern biotechnology, a variety of bio-products with the high economic values have been produced using microorganisms. For molecular cloning and expression studies on the gene of interest, E. coli has been widely used mainly because vector systems are fully developed. Most plasmid vectors currently used for E, coli carry antibiotic-resistant markers. As it is generally believed that the antibiotic resistance markers are potentially transferred to other bacteria, application of the plasmid vectors carrying antibiotic resistance genes as selection markers should be avoided, especially for human consump-tion. By contrast, as LAB have some desirable traits such that the they are GRAS(generally recognized as safe), able to secrete gene products out of cell, and their low protease activities, they are regarded as an ideal organism for the genetic manipulation, including cloning and expression of homologous and heterologous genes. However, the vec-tor systems established for LAB are stil insufficient to over-produce gene products, stably, limiting the use of these organisms for industrial applications. For a past decade, the two popular plasmid vectors, pAM$\beta$1 of Streptococcus faecalis and pGK12 theB. subtilis-E. coli shuttle vector derived from pWV01 of Lactococcus lactis ssp. cremoris wg 2, were most widely used to construct efficient chimeric vectors to be stably maintained in many industrial strains of LAB. Currently, non-antibiotic markers such as nisin resistance($Nis^{r}$ ) are explored for selecting recombi-nant clone. In addition, a gene encoding S-layer protein, slp/A, on bacterial cell wall was successfully recombined with the proper LAB vectors LAB vectors for excretion of the heterologous gene product from LAB Many food-grade host vec-tor systems were successfully developed, which allowed stable integration of multiple plasmid copies in the vec-mosome of LAB. More recently, an integration vector system based on the site-specific integration apparatus of temperate lactococcal bacteriophage, containing the integrase gene(int) and phage attachment site(attP), was pub-lished. In conclusion, when various vector system, which are maintain stably and expressed strongly in LAB, are developed, lost of such food products as enzymes, pharmaceuticals, bioactive food ingredients for human consump-tion would be produced at a full scale in LAB.

• 치위생과학회지
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• 제18권1호
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• pp.18-23
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• 2018

Propolis has been used as a natural remedy in folk medicine worldwide. The antibacterial, antiviral, antifungal, and antiprotozoal aspects of its antimicrobial properties have been widely investigated. However, few studies focused on its applications in dentistry. Many dental diseases are related to various microorganisms in the oral cavity. In this study, we assessed the antimicrobial activity of Korean propolis extract, collected from 6 different regions, on oral pathogenic microorganisms. The propolis samples, collected from 6 different regions (P1: Uijeongbu, P2: Ansan, P3: Hongcheon, P4: Iksan, P5: Gwangju, and P6: Sangju), were dissolved in ethanol at two different concentrations (10 and 50 mg/ml). Three oral bacteria (Streptococcus mutans, Staphylococcus aureus, and Enterococcus faecalis) and one fungus (Candida albicans) were activated in general broth for 24 hours. Microorganisms were diluted and spread onto agar plates, onto which sterilized 6 mm filter papers with or without each propolis sample were placed. After 24 hours of incubation, clear zones of inhibition were observed. All tests were performed in triplicate. The propolis samples showed significant antibacterial and antifungal activity on oral pathogenic microorganisms; in addition, low-concentration groups showed outstanding antimicrobial efficacy on the 4 different microorganisms. Among the samples, P6 had significantly higher antibacterial activity than that of the others against three different bacteria. In particular, a high concentration of P6 showed a significant antifungal effect. In conclusion, we confirmed that Korean propolis has an inhibitory effect on oral pathogenic bacteria and fungi. Therefore, we suggest the possibility of developing oral medicine and oral care products based on Korean propolis.

• 대한화학회지
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• 제9권4호
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• pp.201-210
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• 1965

Leuconostoc mesenteroides P-60, Lactobacillus arabinosus 17-5, Streptococcus faecalis R have been successfully used for the quantitative determination of sixteen amino acids in Undaria pinnatifida (Harvey) Suringar hydrolysate by alkaline and hydrolysis for succesive two hours from two to twelve hours, by means of microbiological assay. And thiamine and riboflavin were fluorometrically determinated by thiochrome and lumiflavin in powder (80mesh) of Undaria pinnatifida (Harvey) Suringar. The results were as follows: 1) Arginine contents was the highest in hydrolysate for two hours, but longer the hydrolysis, the more content Undaria pinnatifida was decreased. 2) The adequate contents of other amino acids were obtained by hydrolysis for six hours. 3) Growth check and improve of Lactobacillus were not identified in determination by microbiological assay for Undaria pinnatifida. 4) The following values were obtained in Undaria pinnatifida hydrolysate six hours: asparatic acid 466, arginine 230, lysine 317, histidine 74, isoleucine 242, methionine 202, phenylalanine 256, proline 231, threonine 231, tyrosine 161, valine 415, glycine 302, leucine 414, glutamic acid 625, cystine (5 hrs.) 53 and tryptophan (8 hrs.) 90mg per nitrogen one gram. 5) Protein score was 81 (limiting factor was isoleucine) and essential amino acids pattern was of satisfactory results. And methionine contained was higher than FAO value or milk value. 6) Sulphur contained amino acids (methionine plus cystine) contained in Undaria pinnatifida were 225mg/N-g. That was satisfactory results. 7) Absorption spectrum of wave length were not different 1% HAc from buffer-sol. (pH 6.8) in dilution for determination of riboflavin. Both methods might be suitable. 8) Thiamine and riboflavin contained in Undaria pinnatifida were ($B_1,\;82.51{\pm}1.1){\gamma}/N-g\;and\;(B_2,\;115.29{\pm}1.5){\gamma}/N-g.$.

• Restorative Dentistry and Endodontics
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• 제20권2호
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• pp.549-576
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• 1995

Bacteria are one of the most important causative agents of the pulpal and periapical diseases. Streptococci are one of the most frequently isolated facultative anarerobic bacteria in the infected root canals. Bacterial cell wall components have a direct effect in the pathogenesis of the pulpal and periapical infections. Hyaluronidase produced by bacteria has been implicated in dissemination of the diseases. The purpose of this study was to evaluate the effect of cell wall extract of streptococci on the L929 cells using inverted microscope and the transmission electron microscopy (TEM). Hyaluronidase production of streptococcal strains were investigated to determine the correlation between the severity of cell damage and the activity of enzymes. Bacterial cell wall extracts of S. sanguis, S. mitis and S. uberis isolated from infected root canals and ATCC type strains of S. mutans (ATCC 10449) and E. faecalis (ATCC 19433) were prepared by sonication and confirmed with SDS-PAGE. Silver stain of SDS-PAGE of sonic extract was efficient at $100{\mu}g$/ml concentration of cell wall protein, while Coomasie blue stain was efficient at $100{\mu}g$/ml concentration. Inverted microscope showed that sonic extract-treated L929 cells were round and detached from the substratum while others lost their fibroblastic shapes. Transmission electron microscopic examination revealed that streptococcal extracts induced death of L929 cells. Sonic extracts of streptococci had variable effect on microstructure of L929 cells. significant chromatin condensation was observed in the nucleus of the cells. Disappearance of cell surface microvilli and nuclear fragments with dense chromatin were observed. The cell nucleus had an irregular shape and numerous large vacuoles were seen in the cytoplasm and some breaks of the cell membrane could be seen. Cell organelles were in various stages of destruction and cristae of mitochondria were disoriented or disappeared. Eighteen strains of streptococci did not produce hyaluronidase.

• Journal of the Korean Wood Science and Technology
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• 제30권1호
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• pp.48-55
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• 2002

대표적인 침엽수인 소나무, 잣나무, 편백, 화백의 잎 정유를 사용하여 수목 정유의 항균활성에 관하여 조사하였다. 항진균활성은 배지점적법을 이용하여 목재부후균인 Gliocladium virens, Tyromyces palustris, Trametes versicolor를, 비부후성 열화균인 Rhizopus stolonifer를, 수목병원균인 Phomopsis albobestita, Endothia nitschkeii, Melanconis juglandis에 대하여, 그리고 항세균활성은 paper disc법과 탁도측정법을 이용하여 그람양성균인 Staphylococcus aureus, Streptococcus faecalis, Bacillus subtilis 및 그람음성균인 Escherichia coli에 대하여 검정하였다. 그 결과, 항진균활성은 편백이 가장 우수한 것으로 나타났으며 그 다음이 소나무와 잣나무로 목재부후균에 대해서는 소나무가 잣나무보다 높은 활성을, 수복병원균에 대해서는 잣나무가 소나무보다 높은 활성을 나타내었다. 그리고 화백 잎 정유가 가장 활성이 낮은 것으로 나타났다. 또한, 항세균활성은 항진균활성과 달리 소나무 잎 정유가 편백보다 높은 활성을 보였으며 그 다음이 잣나무 그리고 화백의 순이었다. 이러한 정유에 따른 항균 스펙트럼의 차이는 각 정유의 성분 변이와 이러한 성분들의 미생물에 대한 작용특이성에 기인하는 것으로 사료되었다.

• Restorative Dentistry and Endodontics
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• 제46권2호
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• pp.20.1-20.11
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• 2021

Objectives: The aim of this study was to evaluate bacterial nanocellulose (BNC) membranes incorporated with antimicrobial agents regarding cytotoxicity in fibroblasts of the periodontal ligament (PDLF), antimicrobial activity, and inhibition of multispecies biofilm formation. Materials and Methods: The tested BNC membranes were BNC + 1% clindamycin (BNC/CLI); BNC + 0.12% chlorhexidine (BNC/CHX); BNC + nitric oxide (BNC/NO); and conventional BNC (BNC; control). After PDLF culture, the BNC membranes were positioned in the wells and maintained for 24 hours. Cell viability was then evaluated using the MTS calorimetric test. Antimicrobial activity against Enterococcus faecalis, Actinomyces naeslundii, and Streptococcus sanguinis (S. sanguinis) was evaluated using the agar diffusion test. To assess the antibiofilm activity, BNC membranes were exposed for 24 hours to the mixed culture. After sonicating the BNC membranes to remove the remaining biofilm and plating the suspension on agar, the number of colony-forming units (CFU)/mL was determined. Data were analyzed by 1-way analysis of variance and the Tukey, Kruskal-Wallis, and Dunn tests (α = 5%). Results: PDLF metabolic activity after contact with BNC/CHX, BNC/CLI, and BNC/NO was 35%, 61% and 97%, respectively, compared to BNC. BNC/NO showed biocompatibility similar to that of BNC (p = 0.78). BNC/CLI showed the largest inhibition halos, and was superior to the other BNC membranes against S. sanguinis (p < 0.05). The experimental BNC membranes inhibited biofilm formation, with about a 3-fold log CFU reduction compared to BNC (p < 0.05). Conclusions: BNC/NO showed excellent biocompatibility and inhibited multispecies biofilm formation, similarly to BNC/CLI and BNC/CHX.

• Animal Bioscience
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• 제35권2호
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• pp.204-216
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• 2022

Objective: The aim of this study was to investigate the effects of dietary supplementation with a multi-strain probiotic (MSP) product containing of Bifidobacterium animalis, Lactobacillus casei, Streptococcus faecalis, and Bacillus cerevisiae on growth, health, and fecal bacterial composition of dairy calves during the first month of life. Methods: Forty Holstein calves (24 female and 16 male) at 2 d of age were grouped by sex and date of birth then randomly assigned to 1 of 4 treatments: milk replacer supplementation with 0 g (0MSP), 2 g (2MSP), 4 g (4MSP), and 6 g (6MSP) MSP per calf per day. Results: Supplementation of MSP did not result in any significant differences in parameters of body measurements of calves during the 30 d period. As the dosage of MSP increased, the average daily gain (p = 0.025) and total dry matter intake (p = 0.020) of calves showed a linear increase. The fecal consistency index of the 2MSP, 4MSP, and 6MSP group calves were lower than that of the 0MSP group calves (p = 0.003). As the dosage of MSP increased, the concentrations of lactate dehydrogenase (p = 0.068) and aspartate aminotransferase (p = 0.081) in serum tended to decrease, whereas the concentration of total cholesterol increased quadratically (p = 0.021). The relative abundance of Dorea in feces was lower (p = 0.011) in the 2MSP, 4MSP, and 6MSP group calves than that in the 0MSP group calves. The relative abundance of Dorea (p = 0.001), Faecalibacterium (p = 0.050), and Mitsuokella (p = 0.030) decreased linearly, whereas the relative abundance of Prevotella tended to increase linearly as the dosage of MSP increased (p = 0.058). Conclusion: The MSP product can be used to reduce the diarrhea, improve the performance, and alter the composition of the fecal bacteria in neonatal dairy calves under the commercial conditions.

• Clinical and Experimental Pediatrics
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• 제46권8호
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• pp.758-762
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• 2003

목 적 : 저자들은 발열을 주소로 입원한 3세 이하의 소아에서 초기 총 백혈구 수, 적혈구 침강 속도, C-반응성 단백질 정량적 검사를 통해 민감도와 특이도가 최대치에 이르는 수치를 차단점으로 선택하여 세균성 감염의 고위험군을 예측하고 항생제 치료의 지표로 삼고자 연구를 하였다. 방 법 : 2001년 6월부터 2002년 6월까지 조선대학교병원 소아과에 발열을 주소로 입원치료 하였던 환아 중 진찰 소견에서 발열에 대한 원인을 발견할 수 없었던 1개월에서 36개월 사이의 71명을 대상으로 하여 후향적으로 조사하였다. 대상 환아들을 세균성 감염과 비세균성 감염으로 분류한 후 각각의 진단 기준의 양성 예측치와 우도비를 계산하고 민감도와 특이도가 최대치에 이르는 수치를 차단점(cut-off point)으로 선택하여 그 수치에서의 민감도와 특이도를 조사하였다. 결 과 : 대상 환아 총 71명(남아 44명, 여아 27명)이고, 평균 연령은 12.7개월이었다. 세균성 감염인 경우는 20례(28%)이었으며, 요로 감염 12례, 세균혈증 5례, 뇌막염 3례 순이었다. 감염균은 E.coli 6례, K.pneumoniae 3례, E. faecalis 3례, Streptococcus ganguinis 3례, Salmonella 2례, S.aureus 1례, Stenotrophomonas maltophilia 1례, Streptococcus constellatus 1례였다. 총 백혈구 수, 적혈구 침강 속도, C-반응성 단백질은 세균성 감염군과 비세균성 감염군간의 유의한 차이를 보였다(P=0.038, 0.009, 0.002). 양성예측치와 우도비는 총 백혈구 수는 20,000/mm^3$ 이상에서 75%, 7.65이었으며, 적혈구 침강 속도는 30-50 mm/hr에서 60%, 3.83이었다. C-반응성 단백질의 양성 예측치와 우도비는 3-6 mg/dL에서 63%, 4.25이었다. 민감도와 특이도가 최대치에 이르는 수치는 총 백혈구 수 $20,000/mm^3$, 적혈구 침강 속도 30 mm/hr, C-반응성 단백질 3.0 mg/dL이었으며, 이 값에서의 민감도는 각각 75%, 79%, 83%, 특이도는 75%, 68%, 77%이었다. 결 론 : 비특이적 소견을 보이는 3세 이하 발열 환아에서 차단점을 총 백혈구 수 20,000/mm^3$, 적혈구 침강 속도 30 mm/hr, C-반응성 단백질 3.0 mg/dL으로 적용할 때 세균성 감염에서 선택적 치료 방침을 세울 수 있게 되리라 생각된다.