• 산업기술연구
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• 제21권B호
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• pp.11-20
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• 2001

This laboratory study examined the impact of free chlorine residual and pipe material on the formation of biofilm in drinking water distribution pipe surfaces. Result of heterotrophic plate counts(HPC) of the biofilm in the tap water-supplied reactor averaged $2.17{\times}10^5CFU/cm^2$ on PVC and $2.43{\times}10^5CFU/cm^2$ on STS 316, respectively. HPCs on the surface exposed to the tap water containing 0.2mg/L of free chlorinne residual averaged $4.24{\times}10^4CFU/cm^2$ on PVC and $6.54{\times}10^4CFU/cm^2$ on STS 316, respectively. Average of HPC/Total direct counts in the tap water-supplied reactor ranged from 1.08%(PVC) to 1.26%(STS 316) and from 0.38%(PVC) to 0.65%(STS 316) in the reactor supplemented with disinfectant, respectively. No correlation was observed between disinfectant addition and biofilm density. With regard to the biofilm formation, little difference existed between PVC and STS 316. Yellow and red pigmented bacteria were the dominant expressions in bulk fluid, whereas non-pigmented bacteria were found dominant in the biofilm. Pink/red pigmented bacteria were found to be facultative anaerobic, while yellow pigmented bacteria and non-pigmented bacteria were found to be obligate aerobic.

• Journal of Periodontal and Implant Science
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• 제30권1호
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• pp.111-120
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• 2000

Purpose We designed this study for the purpose of determining the relationship between periodontal disease activity and PLBW, using the evaluation of probing pocket depth, loss of attachment, gingival index, gingival crevicular fluid amount and subgingival microflora. Methods A total of 100 volunteer mothers(mean age 30.44) at the Department of Obstetrics and Gynecology Seoul National University Hospital were selected for this study.Pregnancy outcomes were categorized into cases and controls in two ways. our definition was based on the following; Group 1 : Any PLBW cases Vs. All NBW controls Group 2 : PLBW cases Vs. NBW controls A periodontal exam was performed on the Ramfjord( #16, 21, 24, 36, 41, 44) teeth and Clinical evaluation consisted of probing pocket depth, loss of attachment, gingival index and gingival crevicular fluid amount. Subgingival plaque samples were collected by three sterile #35 paper points. The total number of anaerobic colonies and aerobic bacteria were enumerated after incubation. Antisera to P. gingivalis, P. intermedia, A. actinomycetemcomitans were produced in white rabbits with live whole cells suspensions. The specific fluorescent bacteria obtained by immunofluorescence and total cell counts obtained by dark-field microscopy were counted on four fields. The percent of each specific microorganism in the total cell count was determined. Results Any PLBW and PLBW cases showed significantly greater probing depth and attachment loss than all NBW and NBW controls. Cases group had significantly increased anaerobic bacterial counts compared with control group and no differences in the other microbes. This study confirmed that periodontal disease is a statistically significant risk factor for PLBW by investigating clinical parameters and subgingival plaque analysis.

• Journal of Microbiology and Biotechnology
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• 제12권4호
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• pp.657-663
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• 2002

Probiotics have been suggested to improve gastrointestinal health in humans. To investigate the effects of Bacillus polyfermenticus SCD administration on fecal microflora and putrefactive metabolites in humans, Bacillus polyfermenticus SCD (4.00${\times}$10$\sub$5/ CFU/mg) was administrated to ten healthy subjects (5 men and 5 women, average age 24 years) three times a day for 2 weeks. Fecal samples were collected before (1st and 2nd weeks, control), during (3rd and 4th weeks), and 2 weeks after the administration. The fo11owing microbial groups were evaluated in the feces: aerobic and anaerobic bacteria, Bacillus polyfermenticus SCD, Lactobacillus, Bifidobacterium, total lactic acid bacteria, Salmonella, Clostridium, Clostridium perfringens, Eubacterium, Staphylococcus, Coliform bacteria, Pseudomunas, and Yeast. Fecal concentrations of total aerobic bacteria (p<0.05, p<0.01, 3rd and 4th weeks), total lactic acid bacteria (p<0.01, 3rd, 4th and 5th weeks), and Bifidobacteria (p<0.05, 4th and 5th weeks) were significantly increased in all subjects, compared to the control, from the 3rd week after the administration of the products. Clostridium (p<0.01, 4th week), Clostridium perfringens (p<0.05, p<0.01, 3rd and 4th weeks), and coliform (p<0.01,5th week) were significantly reduced from the 3rd week of administration. No significant changes in the fecal concentrations of Pseudomonas, Lactobacillus, Eubacterium, Staphylococcus, yeast, and total anaerobes were observed. Six weeks after the administration, the concentration of all rnicroorganlsrns returned to the basal level. Bacillus polyfermenticus SCD was significantly maintained from the 3rd week to 6th week of the study. Despite the absence of a statistical significance, the putrefactive metabolites (ammonia, indole, skatole, and $\rho$-cresol) and the pH value tended to be lower during and after the test periods than the base line. These results show that this probiotic preparation is able to colonize the intestine, and suggest that it may be useful as a beneficial probiotic in humans.

• KSBB Journal
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• 제17권1호
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• pp.80-87
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• 2002

유기물 제거뿐만 아니라 안정적으로 질소와 인의 동시 제거를 위한 순환식 생물막 반응기를 제작, 운전하여 최적의 운전 인자를 도출하고, 질소 제거의 텃 번째 단계인 질산화 및 뒤이은 탈질에 관여하는 미생물들의 군집 구조 분석을 수행하였다. 유기물 제거와 질소와 인의 동시 제거를 위한 순환식 생물막 반응기는 143일 동안 운전되었다. 이 결과 $COD_{cr},\;BOD_5$, SS의 경우 각각 88, 88, 97%의 평균 제거효율을 보였다 이 기간 중 질산화율은 약 96% 정도로 유입 ${{NH_4}^{+}}_{-}N$의 대부분이 제거됨을 보였다. 하지만 탈질율은 평균 45% 정도로 나타났다. 반응기로 유입되는 총 인의 경우 약 44%가 제거되었다. 질소제거의 첫 번째 단계인 질산화가 일어나는 호기성 반응조 내 질산화 미생물의 경우 FISH 관찰 결과, 주요 암모니아 산화균 및 아질산 산화균으로는 Nitrosomonas spp.와 Nitrospira sap.가 관찰되었다. 또한 탈질 반응이 일어나는 준혐기성 반응조에서는 Rhodobacter, Rhodovulum, Roseebacter 그리고 Paracoccus 속에 속하는 탈질 미생물들이 전체 미생물의 약 10~20% 정도를 차지하며 분포하였다.

• Journal of Oral Medicine and Pain
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• 제30권2호
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• pp.277-285
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• 2005

치주질환을 야기하는 세균을 제거하고, 세균집락을 감소시키는 레이저 에너지의 광열적 작용을 이용하여 치주질환의 치료에 대한 효과를 알아보고자, 연세대학교 치과대학병원 구강내과에 내원한 중등도의 치주질환을 가진 환자를 대상으로, 각각 Argon 레이저를 이용한 치은연하 소파술과 통상적인 치은연하 소파술을 시행하여 비교하였다. 시술 전과 시술 1주 후 각각 치은열구액을 채취하여 치주질환의 중요한 원인인 호기성 세균과 혐기성 세균에 대해 배양된 세균 군락수의 변화를 비교하고, 또한 치태지수, 치은지수, 치면열구 출혈지수와 같은 치주질환과 관련된 임상적 지표의 변화를 비교하였다. 연구 결과, 호기성 세균 및 혐기성 세균에 대한 세균 군락 수 비교 시, Argon 레이저를 이용하여 치주치료를 시행한 실험군과 치은연하 소파술을 시행한 대조군 모두 시술 전에 비해 시술 1주 후 세균의 군락 수에 있어서 감소 양상을 나타내었고, 특히 혐기성 세균의 군락 수에 있어서는 통계학적으로 유의한 감소 양상을 나타내었으며(p<0.1), 두 군 사이에 통계학적으로 유의한 차이는 없었다. 또한 치주조직의 상태를 나타내는 지표로서 이용되는 치태지수, 치은지수 및 치은열구 출혈지수의 비교 시 Argon 레이저를 이용하여 치주치료를 시행한 실험군과 치은연하 소파술을 시행한 대조군 모두 시술 전에 비해 시술 1주 후 지수의 감소양상을 나타내었고, 특히 Argon 레이저를 이용한 실험군에서는 치은지수(p<0.1)와 치은열구 출혈지수(p<0.01)가, 치은연하 소파술을 시행한 대조군에서는 치은열구 출혈지수(p<0.01)가 통계학적으로 유의한 감소 양상을 나타내었다. 그러나 두 군 사이에 각각의 지수에 있어서 모두 통계학적으로 유의한 차이는 없었다. 이상의 연구 결과, 중등도의 치주질환의 치료에 있어서 Argon 레이저는 치은연하 소파술을 대신하거나 또는 치은연하 소파술과 병용하여 치료 효과를 더욱 상승시켜주는 유의한 치료법이라고 사료되며, 본 연구 결과 임상적 적용 가능성이 있다고 보여지나, 보다 효과적으로 임상에 적용하기 위해서는 앞으로 충분한 표본의 확보 및 장기적인 예후 관찰을 포함한 더욱 정밀하게 조절된 연구가 필요하리라고 사료된다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권1호
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• pp.48-55
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• 2003

The purpose of this study was to isolate and identify the bacteria in osteomyelitis lesion of 3 patients. Two lesions were due to the post-infection after extraction. The other was resulted from mal-fixation of both sides of mandibular angles. Pus samples were collected by needle aspiration from the lesion and examined by culture method. Bacterial culture was performed in three culture systems (anaerobic, $CO_2$, and aerobic incubator). Identification of the bacteria was performed by 16S rRNA gene cloning and nucleotide sequencing method. Our results showed that Streptococci species was predominantly isolated in both lesions of extraction socket. Only one species (Proteus vulagris) was detected in lesion of mandibular angle. This study was not sufficient to identify the causative bacteria in those osteomyelitis. However, our data may be offered the clue to solve the problem.

• 한국환경과학회지
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• 제28권10호
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• pp.851-861
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• 2019

In this study, we performed a sediment elution experiment to evaluate water quality in terms of phosphorus, as influenced by the dissolved oxygen consumed by sediments. Three separate model column treatments, namely, raw, calcined, and sonicated oyster shell powders, were used in this experiment. Essential phosphorus fractions were examined to verify their roles in nutrient release from sediment based on correlation analyses. When treated with calcined or sonicated oyster shell powder, the sediment-water interface became "less anaerobic," thereby producing conditions conducive to partial oxidation and activities of aerobic bacteria. Sediment Oxygen Demand (SOD) was found to be closely correlated with the growth of algae, which confirmed an intermittent input of organic biomass at the sediment surface. SOD was positively correlated with exchangeable and loosely adsorbed phosphorus and organic phosphorus, owing to the accumulation of unbound algal biomass-derived phosphates in sediment, whereas it was negatively correlated with ferric iron-bound phosphorus or calcium fluorapatite-bound phosphorus, which were present in the form of "insoluble" complexes, thereby facilitating the free migration of sulfate-reducing bacteria or limiting the release from complexes, depending on applied local conditions. PCR-denaturing gradient gel electrophoresis revealed that iron-reducing bacteria were the dominant species in control and non-calcined oyster shell columns, whereas certain sulfur-oxidizing bacteria were identified in the column treated with calcined oyster powder.

• 생명과학회지
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• 제18권10호
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• pp.1426-1434
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• 2008

본 시험은 혐기성 박테리아, 효모 및 곰팡이로 제조한 Synbiotics를 TMR에 첨가하여 발효시킨 후, 개봉하여 공기에 노출시킨 기간에 따른 보존성에 미치는 영향을 알아보기 위하여 수행되었다. 처리구는 무처리 대조구인 US구, 혐기성 박테리아와 prebiotic으로 만든 BS구, 혐기성 효모와 prebiotic로 구성된 YS구, 혐기성 곰팡이와 prebiotic으로 구성된 MS구, 혐기성 박테리아와 혐기성 곰팡이 그리고 prebiotic로 만든 BMS구, 혐기성 효모와 혐기성 곰팡이 그리고 prebiotics 로 만든 YMS구, 혐기성 박테리아와 혐기성 효모 그리고 prebiotics로만든 BYS구, 마지막으로 혐기성 박테리아, 효모 그리고 곰팡이 복합물과 prebiotics로 구성된 BMYS구로서 총 8 처리구로 나누었다. 개봉 후 노출 기간(1, 3, 5, 7, 14 및 21일)별 3반복으로 총 144개의 bag을 공시사료로 제조하였다. CMCase, xylanase 및 amylase의 평균 활성은 통계적 유의차는 없었으나 효모가 첨가된 BYS구 및 YMS구에서 좋은 편이었고, 총 세균수에서도 효모가 첨가된 구(YMS, BYS)에서, 곰팡이 수에서도 효모 첨가구(YMS, BMYS, BYS)에서 낮은 경향이었다. 병원성 균인 E. coli는 BYS구와 BMYS구, Salmonella균은 BMYS구와 YS구, 그리고 Shigella 균은 BMS와 BMYS구에서 대체로 낮았으나, MS구에서는 대조구보다도 모든 병원균에 더 많이 오염된 것으로 나타났다. 이상의 결과들을 살펴볼때, 혐기성 효모 첨가구(BYS, YMS, BMYS)가 저장성에서 효과가 있는 것으로 나타났으며, 특히 모든 미생물을 혼합한 BMYS구에서 영양소 함량과 건물 감량 및 병원성균 수 등에서 좋은 결과를 나타내어 혐기발효 TMR의 보존에 유리할 것으로 판단된다.

• 미생물학회지
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• 제46권3호
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• pp.286-290
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• 2010

C-1화합물은 고염분성 환경의 혐기적인 퇴적층에서 관찰되며, 이 퇴적층의 표면과 수면에는 호기성 메틸영양미생물의 잠재적인 서식지가 된다. 염전과 갯벌에서 채취한 토양 시료를 접종원으로 하여 메탄올을 탄소원과 에너지원으로 공급하고 염분농도에 따라 계대배양한 후 메탄올 산화 세균 성장 조건을 살펴 본 결과, 메탄올 산화 세균이 성장 할 수 있는 염분의 최대 농도는 20% 조건이었다. 변성 구배 젤 전기영동 (Denaturing gel gradient electrophoresis)을 이용하여 농화배양액 내 미생물 군집구조를 분석한 결과, 메탄올 산화 미생물인 Methylophaga 관련 세균이 우점하는 것으로 나타났다. 정량 PCR결과 고세균이 세균의 1-10%로 존재하는 것으로 나타났다. 세균용 항생제 실험결과, 메탄올 산화가 억제되어 고세균이 메탄올 산화에 관여하지 않는다는 것을 추정할 수 있었다. 이번 연구를 통해, 메틸영양세균이 고염분환경(염분 농도 20%까지)에서도 C-1 화합물을 산화할 수 있음을 확인 할 수 있었다.

• Advances in nano research
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• 제15권4호
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• pp.355-366
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• 2023

Biological corrosion, a crucial aspect of metal degradation, has received limited attention despite its significance. It involves the deterioration of metals due to corrosion processes influenced by living organisms, including bacteria. Soil represents a substantial threat to pipeline corrosion as it contains chemical and microbial factors that cause severe damage to water, oil, and gas transmission projects. To combat fouling and corrosion, corrosion inhibitors are commonly used; however, their production often involves expensive and hazardous chemicals. Consequently, researchers are exploring natural and eco-friendly alternatives, specifically nano-sized products, as potent corrosion inhibitors. This study aims to environmentally synthesize silver nanoparticles using an extract from Lagoecia cuminoides L and evaluate their effectiveness in preventing biological corrosion of buried pipes in soil. The optimal experimental conditions were determined as follows: a volume of 4 ml for the extract, a volume of 4 ml for silver nitrate (AgNO3), pH 9, a duration of 60 minutes, and a temperature of 60 degrees Celsius. Analysis using transmission electron microscopy confirmed the formation of nanoparticles with an average size of approximately 28 nm, while X-ray diffraction patterns exhibited suitable peak intensities. By employing the Scherer equation, the average particle size was estimated to be around 30 nm. Furthermore, antibacterial studies revealed the potent antibacterial activity of the synthesized silver nanoparticles against both aerobic and anaerobic bacteria. This property effectively mitigates the biological corrosion caused by bacteria in steel pipes buried in soil.