• Restorative Dentistry and Endodontics
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• v.27 no.2
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• pp.183-195
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• 2002

흑색 색소를 형성하는 그람음성 혐기성 세균은 급성 임상 증상을 가진 환자의 근관에서 자주 발견되는 세균으로서 세균 및 세균의 성분과 산물이 치근단 병소의 생성과 밀접하게 연관된 것으로 알려져 있다. 본 연구는 흑색 색소를 형성하는 그람음성 혐기성 세균 중 가장 발현율이 높은 Prevotella nigrescens가 배양된 세포에 미치는 세포 독성을 연구하고자 하였다. 두 가지 세포주 및 사람의 치은섬유모세포를 일차배양하여 사용하였으며, 세포주에 따른 독성 발현에 차이가 있는지를 비교하였다. P. nigrescens ATCC 33563 표준 균주 및 임상 균주로는 환자의 감염된 근관으로부터 165 rRNA primer를 사용한 중합효소 연쇄반응으로 P. nigrescens 6 균주를 동정하여 사용하였다. 세균배양액, 세균의 초음파 추출단백질 및 lipopolysaccharide (LPS)를 MC3T3-El 조골세포, NIH3T3 섬유모세포 및 치은섬유모세포에 첨가한 후 MTT분석법으로 세포의 활성을 측정하였으며, 세포의 형태학적 변화를 도립현미경으로 관찰하였다. 세균배양액을 100$\mu\textrm{l}$ 첨가한 경우는 세가지 세포주 모두에서 통계적으로 유의하게 세포의 활성을 억제하였다. 세균의 초음파 추출단백질 12.5$\mu\textrm{g}$/ml 와 25$\mu\textrm{g}$/ml 는 NIH3T3세포에 통계적으로 유의한 세포독성을 보였다. 세 가지 세포주에 대한 LPS의 세포 독성 효과는 첨가된 LPS의 농도 및 균주에 따라 다양하게 나타났다. 심하게 손상된 세포는 세포의 단일층이 수축되고 세포가 응집되었으며 세포가 배양용기의 바닥에서 떨어지는 양상이 도립 현미경하에서 관찰되었다. 본 연구의 결과 P. nigrescens가 숙주 반응을 조절하여 치수 및 치근단 병소의 유발 및 악화에 기여하는 세균으로 작용할 수 있음을 시사한다. 조직과 함께 제거하고 포르말린에서 48시간 고정시킨 후 파라핀에 포매한 다음에 micro-tome을 사용하여 6$\mu\textrm{m}$로 serial section을 시행하였다. 정중선 부위의 시편에 Hematoxylin-Eosin staining을 시행한 후 Olsson, Orstavik 그리고 Mjor 등의 방법에 따라 조직학적 변화를 관찰한 후 slight(1), moderate(2), severe inflammation(3)의 단계로 분류하였다. 얻어진 결과를 통계처리 프로그램인 Jandel사의 Sigmastat을 이용하여 Kruskal Wallis Test로 통계처리를 하였다. 결과 : (Table omitted) 결론 : 1) Pulp Canal Sealer를 제외한 모든 군에서 시간이 지남에 따라 유의성 있게 염증이 감소되는 양상을 보였다(p<0.05). 2) Pulp Canal Sealer는 1주, 2주, 12주에서 강한 염증반응을 보였다. 3) AH 26과 AH Plus에서는 1주, 2주에서 강한 염증반응을 보였으나 12주에서는 염증반응이 감소하였다. 4) 새로 개발된 봉함제 Adseal-1,2는 1주, 2주에서는 가장 약한 염증반응을 보이나 4주, 12주 후에는 AH Plus와 비슷한 수준의 염증 반응을 보였다. 5) Pulp Canal Sealer를 제외한 모든 군에서 인정할 만한 생체친화성을 보였다. 6) Adseal-2가 Adseal-1에 비하여 전반적으로 낮은 염증반응을 보였다. 7) 각 군간 결과의 차이에 통계적 유의성은 없었다(p>0.05).mmunity. Then, a hierarchical language is to defeat its own purpose.중 행정부가 북한에 대해 실시한 포용정책이 어떠한 성과를 거두고 어떠한 문제점을 간과하고 있는가에 대해 논의하고, 대북 정책의 새로운 지평을 논의하는 것을 목적으로 하고 있다. 1) 포용 정책은 세계의

• Applied Biological Chemistry
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• v.37 no.4
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• pp.295-302
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• 1994

For the development of biological wastewater treatment process using photosynthetic bacteria (PSB), photosynthetic sludge process consisted of anaerobic digestion and PSB reactor were designed for the treatment of swine wastewater and the optimal operating conditions in flask-scale were examined. Photosynthetic bacteria from soil, pond, rice field, ditch etc. were isolated in synthetic medium containing high amount of organic acids and finally isolated one strain KK14 which showed the most degradating ability of organic acids was selected for the treatment of swine wastewater. It was identified as Rhodopseudomonas palustris. In the anaerobic digestion stage, the maximum organic acid productivity was obtained at pH 5.0, $37^{\circ}C$, HRT 2 day and under anaerobic standing condition. The optimal operating conditions of PSB reactor for the treatment of swine wastewater were pH 7.0, $30^{\circ}C$ under 4,000 lux illumination, and optimal initial COD loading (kg COD/kg D. C. W of PSB) was 2 (20% v/v seeding) in the main purification stage. Maximum removal rate of COD reached 92% under the above optimal conditions for 5 days.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.4
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• pp.515-521
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• 2004

Anaerobic digestion has many advantages over the more conventional aerobic treatment processes such as low levels of excess sludge production, low space (area) requirements, and the production of valuable biogas. The purpose of this study was to evaluate the effect of organic loading rate of anaerobic digestion on thermophilic($55^{\circ}C$) and mesophilic($35^{\circ}C$) conditions. Fluorescent in situ hybridization (FISH) method was also used to study the microbial community in the reactors. The stabilizing time in mesophilic anaerobic reactors was shorter as approximately 20 days than 40 days in the thermophilic anaerobic reactors. The amount of methane production rate in anaerobic reactors was independent of the concentrations of supplied substrates and the amount of methanogens. When the microbial diversity in the mesophilic and thermophilic reactors, which had been treated with acetate-based artificial wastewater, were compared, it was found that methanogenesis was carried out by microbial consortia consisting of bacteria and archaea such as methanogens. To investigate the activity of bacterial and archaeal populations in all anaerobic reactors, the amount of acetate was measured. Archaea were predominant in all reactors. Interestingly, Methanothrix-like methanogens appeared in mesophilic anaerobic reactors with high feed substrate concentrations, whereas it was not observed in thermophilic anaerobic reactors.

• Journal of Hydrogen and New Energy
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• v.13 no.4
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• pp.321-329
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• 2002

Clostridium butyricum, Lactobacillus amylophillus, Lactobacillus amylovorus, Lactobacillus acidophillus, AI-9 produced hydrogen and /or organic acids using glucose, lactose and starch at the anaerobic culture conditions. Cl. butyricum NCIB 9576 evolved 1,700 ml H2/L-culture broth and accumulated butyric acid, acetic acid, propionic acid and ethanol in its culture broth when lactose was used as a carbon source during 24 hrs of fermentation. L. amylovorus ATCC 33620 accumulated lactic and acetic acids and some reducing sugars when starch was used as a carbon source without hydrogen production. Instead of starch as a carbon source, L. amylovorus ATCC 33620 produced lactic acid from algal biomass during fermentation and the acid-heat or freeze-thaw pretreatment of algal biomass accelerate the lactic acid fermentation.

• Korean Journal of Microbiology
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• v.11 no.2
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• pp.101-106
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• 1973

The microwave of 2450 MHz, generated by a household cooking oven, was evaluated for its applicability to melt various rehydrated media and to remove dissolved oxygen from tubed media for anaerobic culture. The effect on the sterilization of E. coli in selective media was also evaluated. The following results were obtained. 10 The microwave oven was useful in saving time for melting media and in eliminating heat and combustion gas from the laboratory, which were inevitable by-products in the conventional flame method. 2) Dissolved oxygen could be removed without boiling over by exposing the tubes of anaerobic culture medium after putting them in a wire basket in a beaker with water. 30 The count of E. coli during the melting of MacConkey and EMB agar were similar to those treated with open flame. The microwave treatment was not considered a possible mean to replace autoclaving even in these selective media.

• Applied Biological Chemistry
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• v.34 no.2
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• pp.130-133
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• 1991

The distribution of acid producing bacteria and general bacteria in 23 samples of Korean traditional Meju loaves was investigated and the strains isolated from the samples identified. The acid producing bacteria occurred more in outer part than inner part and anaerobic acid producing bacteria showed higher tendency of occurrence compared with the aerobes in each part. The average number of nonhalophilic and halotolerant bacteria belonging to aerobes were counted as $24{\times}10^6$ and $33{\times}10^5$ and the average number of those belonging to anaerobes $10{\times}10^7$ and $58{\times}10^5$ cells/g, respectively. The general bacteria isolated more in outer part than inner part and its average number was $62{\times}10^7$ cells/g. In the isolates, 2 aerobic acid producing strains were identified as Micrococcus spp., 3 anaerobic acid producing strains as Streptococcus sp., Pediococcus sp. and Lactobacillus sp., and 2 strains of aerobic general bacteria as Bacillus spp.

• Microbiology and Biotechnology Letters
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• v.20 no.4
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• pp.430-436
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• 1992

Hydrogen evolution by mixed fermentation of Clostn"dium butyn"cum and photosynthetic bacteria which were capable of consuming clostridial metabolites and evolving hydrogen was investigated. Acetate and butyrate formed from anaerobic clostridial fermentation were efficiently utilized by Rhodopseudomonas sPhaeroides K-7. For complete bioconversion of clostridial metabolites such as acetate and butyrate into hydrogen, mixed culture of both anaerobic organisms forming molecular hydrogen was performed. By the mixed culture, the yield of hydrogen production increased by 20 to 75% and the levels of clostridial metabolites such as acetate, butyrate decreased in the fermentation broth. Influence of cell mixing ratio. mixing time and inoculum level on hydrogen evolution by mixed culture were examined. And then cometabolic pattern compared with in pure culture was observed as time course.

• Korean Journal of Microbiology
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• v.54 no.2
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• pp.146-148
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• 2018

Fusobacterium animalis (formerly Fusobacterium nucleatum subsp. animalis) is a Gram-negative, anaerobic, and filament-shaped bacterium. F. animalis may be a part of normal flora and a periodontopathogen of human oral cavity. F. animalis KCOM 1280 (= ChDC F318) was isolated from a human periodontitis lesion. In this report, we present the draft genome sequence of F. animalis KCOM 1280.

• The Journal of the Korean Society for Microbiology
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• v.21 no.4
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• pp.503-513
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• 1986

Previous studies have developed the technique of topical application of tetracycline(TC) into the periodontal pockets and examined the change of clinical parameters and subgingival microbial morphotypes. The purpose of this study was to longitudinally examine the clinical and microbiological effects of topically applied TC in a double-blind and split-mouth design. Thirteen patients with moderate periodontitis, who were treated with or without TC application and scaling treatment, were examined. TC gel(3%) was used to apply into the selected periodontal pockets twice a week for 2 weeks. During the experiment, clinical parameters and subgingival microbial morphotypes were examined, and for isolation of black-pigmented Bacteroides(BPB) and streptococci, an anaerobic sample culturing was done at week 0, 2, and 7. In clinical observation the TC-scaled group exhibited a significant decrease of Gingival Inflammatory Index, Plaque Index, Sulcus Bleeding Index, pocket depth, and gingival crevicular fluid when compared to the TC-unsealed, placebo-scaled, and placebo-unsealed groups. The result of microbial morphotype observation showed a significant increase of coccal form and a decrease of spirochetes in the TC-scaled, TC-unscaled, and placebo-scaled groups. The culture study of streptococci revealed that TC with scaling treatment resulted in a significant increase of S. sanguis I at week 2, but its proportion had returned to the base line level. The anaerobic culture study showed that BPB was significantly reduced in the TC-scaled and TC-unsealed groups at week 7. Among BPB species, B. intermedius declined significantly with time treatment(week 2 and 7) in the TC-scaled and TC-unsealed groups. These results suggest that the settled pathogenic microflora can be succeeded by nonpathogenic microflora in periodontal pockets after TC treatment.

• Journal of Life Science
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• v.34 no.10
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• pp.673-681
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• 2024

Periodontal disease is a significant oral health issue, with halitosis-inducing bacteria being one of its primary causes. Among these bacteria, the anaerobic pathogen Porphyromonas gingivalis is known to accelerate the progression of periodontitis. Effective control and prevention of these bacteria are therefore crucial for the management and prevention of periodontal diseases. The aim of this study was to explore methods for effectively controlling halitosis-causing bacteria to enhance oral hygiene and the prevention of halitosis. We focused on Dendropanax morbifera, a traditional Korean medicinal plant known for its antimicrobial, anti-inflammatory, and antioxidant properties. Specifically, we investigated the antimicrobial effects of D. morbifera leaf extracts and fermented sap against P. gingivalis. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of the leaf extracts and fermented sap were determined under anaerobic conditions. The efficacies in reducing malodor were also evaluated using detection tubes to measure by measuring the concentrations of hydrogen sulfide (H₂S) and ammonia (NH₃) using detection tubes. Both the extracts and sap exhibited significant antimicrobial activity against P. gingivalis. Furthermore, both test materials effectively reduced bacterial production of H₂S and NH₃ gases. Field emission scanning electron microscopy observations revealed that bacterial cell wall damage began at the MIC levels, with complete cell wall destruction observed at the MBC levels. These results provide valuable data regarding the antimicrobial and halitosis-reducing effects of D. morbifera leaf extracts and fermented sap and support the potential use of D. morbifera in developing new oral hygiene products.