• 대한환경공학회지
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• 제32권11호
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• pp.1017-1023
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• 2010

본 연구에서는 지질매질체내에서 계면활성제(비이온성 계면활성제(Tween 20), 생계면활성제)가 박테리아(Bacillus subtilis ATCC 6633)의 이동 증진에 미치는 영향을 분석하였다. 계면활성제가 존재하는 다양한 실험조건에서 석영모래(입경분포: 0.5~2.0 mm, 평균입경: 1.0 mm)로 충진된 칼럼을 이용하여 박테리아의 이동에 관한 칼럼실험을 수행하였고, 박테리아 파과곡선으로부터 질량회수율과 부착효율 등을 정량화하였다. 실험결과, MSM(박테리아 성장에 필요한 무기물 배지)의 존재 하에서 매질체 표면에 박테리아의 부착이 상당히 증가하였는데(특히, 주입부분에), 이는 MSM으로 인한 이온강도의 증가 때문이다. 계면활성제가 존재할 경우에는, 계면활성제로 인하여 매질체내에서 박테리아 이동이 증진됨을 관찰할 수 있었다. 또한, MSM과 생계면활성제 주입방법에 따른 박테리아의 이동을 비교한 결과, 박테리아의 이동 증진을 위한 주입조건은 박테리아를 함유한 MSM용액보다 계면활성제를 선주입하거나, 또는 MSM용액과 계면활성제를 동시주입하는 것이 효과적임을 알 수 있었다. 본 연구를 통해 계면활성제의 존재와 주입방법이 박테리아의 이동에 영향을 미칠 수 있음을 알 수 있었다.

• Preventive Nutrition and Food Science
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• 제7권2호
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• pp.139-145
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• 2002

Hen egg-white lysozyme, ovalbumin, egg-yolk phosvitin, acid-precipitated soy protein and $\alpha$$_{sl}$ milk casein were covalently linked with galactomannan through a controlled dry-heating at 6$0^{\circ}C$ under 79% relative humidity without any chemical reagent. Neoglycosylation by the covalent binding of polysaccharide chains brought a significant improvement into the surface functionalities of food proteins. Excellent emulsifying properties and foaming properties were observed in all protein-galactomannan conjugates. Bacterial mutagenesis tests and animal dose test were done to evaluate the food safety of the protein-galactomannan conjugates. The neo-glycoproteins were negative for Ames test using Salmonella typhimurium TA100 (hisG46) and TA98 (hisD3052) strains, and rec-assay using Bacillus subtilis Hl7 (rec) and M45 (re $c^{+}$) strains. All substances were also nontoxic for oral administration to rats. L $D_{50}$ 's of these substances were all more than 7.5 g/kg body-weight of rat. No effect was also observed in the weight increases and the concentrations of total cholesterol, triglyceride and phospholipids in blood serum of the administrated rats with 7.5 g/kg conjugates. Thus, Maillard-type protein-polysaccharide conjugates prepared by covalent attachment of galactomannan to food proteins were proposed to be useful as a safe functional biopolymer in this study.y.

• Journal of Periodontal and Implant Science
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• 제52권2호
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• pp.116-126
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• 2022

Purpose: This study evaluated the efficacy of treating periodontitis using subgingival nano-hydroxyapatite powder with an air abrasion device (NHAPA) combined with scaling and root planing (SRP). Methods: A total of 28 patients with stage III periodontitis (grade B) were included in this study, although 1 was lost during follow-up and 3 used antibiotics. The patients were divided into a test group and a control group. All patients first received whole-mouth SRP using hand instruments, and a split-mouth approach was used for the second treatment. In the test group, the teeth were treated with NHAPA for 15 seconds at 70% power per pocket. Subgingival plaque samples were obtained from the 2 deepest pockets at the test and control sites before treatment (baseline) and 3 months after treatment. The full-mouth plaque index (PI), gingival index (GI), papillary bleeding index (PBI), bleeding on probing (BOP), probing depth (PD) and clinical attachment level (CAL) were recorded at baseline and at 1- and 3-month post-treatment. Real-time polymerase chain reaction was used to determine the colonisation of Treponema denticola (Td), Porphyromonas gingivalis (Pg), and Aggregatibacter actinomycetemcomitans in the subgingival plaque. Results: From baseline to the first month, the test group showed significantly larger changes in BOP and CAL (43.705%±27.495% and 1.160±0.747 mm, respectively) than the control group (36.311%±27.599% and 0.947±0.635 mm, respectively). Periodontal parameters had improved in both groups at 3 months. The reductions of PI, GI, BOP, PD, and CAL in the test group at 3 months were greater and statistically significant. The total bacterial count and Td and Pg species had decreased significantly by the third month in both groups (P<0.05). Conclusions: Applying NHAPA in addition to SRP improves clinical periodontal parameters more than SRP alone. Subgingival NHAPA may encourage clot adhesion to tooth surfaces by increasing surface wettability.

• Journal of Periodontal and Implant Science
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• 제54권1호
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• pp.37-43
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• 2024

Purpose: The inflammatory response due to inflammatory cytokines, bacterial pathogens, and the altered lipoprotein metabolism in patients with periodontitis indicates that infection with periodontal anaerobic bacteria may influence atherogenesis in vitro and in vivo. We aimed to explore the effect of periodontitis concerning clinical and ultrasound markers of early atherosclerosis. Methods: In this case-control study, a total of 30 systemically healthy adults (15 with periodontitis and 15 without periodontitis) over 40 years of age were studied. Periodontitis was determined by measuring the clinical attachment level (CAL) and radiographic bone loss (RBL). Conventional cardiovascular risk factors, including body mass index, serum levels of total cholesterol (TCH), triglycerides (TG), and high-density and low-density lipoprotein (HDL and LDL, respectively) cholesterol were evaluated. Carotid artery intima-media thickness (IMT) was measured using ultrasonography. Results: The mean values of the CAL and carotid IMT were 5.02±0.9 mm and 0.084±0.01 cm vs. 1.6±0.61 mm and 0.072±0.02 cm in the periodontitis and healthy groups, respectively, reflecting statistically significant differences (P=0.001 and P=0.037, respectively). There were statistically significant differences in the serum levels of TCH, TG, and LDL between the 2 groups (P=0.017). The CAL and RBL were positively associated with carotid IMT and serum cholesterol levels, except for HDL, whereas tooth loss was not associated with any markers (P<0.05). Compared to the healthy group, participants with periodontitis exhibited 2.09 times higher odds (95% confidence interval, 1.22-3.59) of having subclinical atherosclerosis. Conclusions: The presence of periodontitis increased the risk of atherosclerosis.

• Asian-Australasian Journal of Animal Sciences
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• 제20권9호
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• pp.1397-1401
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• 2007

An in situ experiment was conducted to find out whether Tween 80 improves rice straw digestion through increased adhesion of major fibrolytic bacteria. Rice straw was sprayed with various levels of Tween 80 non-ionic surfactant or SDS ionic surfactant 24 h before incubation in the rumen of Holstein steers. Dry matter (DM) disappearance and adhesion of F. succinogenes, R. flavefaciens and R. albus on rice straw after in situ incubation were measured by real-time PCR. Application of Tween 80 increased DM disappearance, which was more noticeable at an application level of 1% compared to lower application levels. Application of SDS resulted in an opposite response in DM disappearance with highest reduction in DM disappearance at 1% level. In a subsequent in situ experiment, higher Tween 80 was applied to rice straw in an attempt to find the optimum application level. Tween 80 at 2.5% gave better DM disappearance than 1% with a similar result at 5%. Therefore, an adhesion study was carried out using rice straw treated with 2.5% Tween 80. Our results indicated that Tween 80 reduced adhesion of all three major rumen fibrolytic bacteria to rice straw. Present data clearly show that improved DM disappearance by Tween 80 is not due to increased bacterial adhesion onto substrates.

• Journal of Microbiology and Biotechnology
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• 제33권3호
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• pp.329-338
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• 2023

Enterohemorrhagic Escherichia coli (EHEC) is a foodborne pathogen that produces attaching and effacing lesions on the large intestine and causes hemorrhagic colitis. It is primarily transmitted through the consumption of contaminated meat or fresh produce. Similar to other bacterial pathogens, antibiotic resistance is of concern for EHEC. Furthermore, since the production of Shiga toxin by this pathogen is enhanced after antibiotic treatment, alternative agents that control EHEC are necessary. This study aimed to discover alternative treatments that target virulence factors and reduce EHEC toxicity. The locus of enterocyte effacement (LEE) is essential for EHEC attachment to host cells and virulence, and most of the LEE genes are positively regulated by the transcriptional regulator, Ler. GrlA protein, a transcriptional activator of ler, is thus a potential target for virulence inhibitors of EHEC. To identify the GrlA inhibitors, an in vivo high-throughput screening (HTS) system consisting of a GrlA-expressing plasmid and a reporter plasmid was constructed. Since the reporter luminescence gene was fused to the ler promoter, the bioluminescence would decrease if inhibitors affected the GrlA. By screening 8,201 compounds from the Korea Chemical Bank, we identified a novel GrlA inhibitor named Grlactin [3-[(2,4-dichlorophenoxy)methyl]-4-(3-methylbut-2-en-1-yl)-4,5-dihydro-1,2,4-oxadiazol-5-one], which suppresses the expression of LEE genes. Grlactin significantly diminished the adhesion of EHEC strain EDL933 to human epithelial cells without inhibiting bacterial growth. These findings suggest that the developed screening system was effective at identifying GrlA inhibitors, and Grlactin has potential for use as a novel anti-adhesion agent for EHEC while reducing the incidence of resistance.

• 대한치과의사협회지
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• 제19권7호통권146호
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• pp.625-634
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• 1981

A Scanning Electron Microscopic Study of the root surface changes was carried out in advanced periodontal disease. The results obtained were summerized as follow; 1. The root surface of cementoenamel junction of healthy root showed smooth surface, while the root surface of diseased state showed covering of deposits which regareded as a course of calcification. 2. At the mid-portion of the root, the regular cemental projection were observed on the healthy root surface and on the root surface of diseased state, cemental projection showed relatively irregular pattern. 3. On the root surface which consist of wall of periodontal pocket, there were various deposits which could be considered as subgingival calculus, bacterial plaque and epithelial attachment remnant. 4. The bottom area of the pathologic pocket, tearing altered collagen fibers were seen on the root surface. 5. At the apical portion of root surface, calcified fibers ran parallel to the root surface in healthy tooth and the fiber bundles of periodontal ligament were seen in the diseased state.

• The Plant Pathology Journal
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• 제35권1호
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• pp.51-62
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• 2019

A great variable response was observed when PP-3 and PP-J encumbered with 116 populations of root knot nematode (RKN) at two different temperatures ($25{\pm}2^{\circ}C$ and $30{\pm}2^{\circ}C$) and concentrations ($10^4$ and $10^5$ spores/ml). The PCR reaction amplified intergenic region between cytochrome oxidase subunit II gene (COII) and large subunit of rRNA gene (lrRNA) of the mitochondrial genome of different RKN species. The primer C2F3 and 1108 identified M. incognita with the highest frequency (52.6%) followed by M. javanica (36.8%) and M. arenaria (10.5%). The sizes of PCR products were 1.7 kb for M. incognita and M. javanica populations while populations of M. arenaria produced 1.1 kb fragment. The digestion with Hinf I yielded three different fragment length patterns on 1.5 % agarose gel. From current research it is concluded that intra-Meloidogyne genetic variability exist in RKN populations which have better encumbrance with P. penetrans.

• Journal of Microbiology and Biotechnology
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• 제33권1호
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• pp.15-27
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• 2023

The incidence of melioidosis cases caused by the gram-negative pathogen Burkholderia pseudomallei (BP) is seeing an increasing trend that has spread beyond its previously known endemic regions. Biofilms produced by BP have been associated with antimicrobial therapy limitation and relapse melioidosis, thus making it urgently necessary to understand the mechanisms of biofilm formation and their role in BP biology. Microbial cells aggregate and enclose within a self-produced matrix of extracellular polymeric substances (EPSs) to form biofilm. The transition mechanism of bacterial cells from planktonic state to initiate biofilm formation, which involves the formation of surface attachment microcolonies and the maturation of the biofilm matrix, is a dynamic and complex process. Despite the emerging findings on the biofilm formation process, systemic knowledge on the molecular mechanisms of biofilm formation in BP remains fractured. This review provides insights into the signaling systems, matrix composition, and the biosynthesis regulation of EPSs (exopolysaccharide, eDNA and proteins) that facilitate the formation of biofilms in order to present an overview of our current knowledge and the questions that remain regarding BP biofilms.

• Journal of Animal Science and Technology
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• 제55권1호
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• pp.41-49
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• 2013

본 연구는 효모(Saccharomyces cerevisiae)가 조사료의 반추위 미생물 분해 및 섬유소 분해 박테리아의 군집 변화에 미치는 관계를 검증하고자, 생효모 배양물 첨가 및 급여가 볏짚 소화율에 미치는 영향을 in vitro 및 in situ 실험을 통해 측정하였고, 볏짚 분해 시 볏짚 표면에 부착한 섬유소분해 박테리아 군집의 변화를 real-time PCR 방법을 이용하여 비교 분석하였다. 생효모 배양물의 첨가 수준(0.0, 0.2, 0.4, 0.6, 0.8 및 1.0%)에 따른 볏짚의 in vitro 건물 소화율을 비교 하였을 때 첨가 수준이 증가 할수록 소화율도 점진적으로 높아 졌다. 특히, 생효모 배양물의 첨가 수준을 0.6% 이상으로 하였을 때 0.0, 0.2 및 0.4% 첨가보다도 확연한 소화율 증가를 보이기 시작하였다(p<0.05). 또한 효모배양물의 0.6% 첨가를 NaOH 4% 처리 볏짚 및 무처리 볏짚에 적용하여 소화율을 재평가하였을 때 두 가지 볏짚 모두에서 효모배양물 첨가에 의하여 볏짚 소화율이 유의적으로 증가하였다(p<0.05). 생효모 배양물을 한국재래산양에 실제 급여에 의한 볏짚의 in situ 건물소화율을 24 및 48 시간 후에 관측하였을 때 NaOH 무처리 볏짚의 효모배양물 비급여구의 소화율이 가장 낮았고, NaOH 무처리 볏짚의 효모배양물 급여구, 4% NaOH 처리 볏짚의 효모배양물 비급여구, 그리고 4% NaOH 처리 볏짚의 효모배양물 급여구 순으로 소화율이 유의적으로 각각 증가하였다(p<0.05). 이는 NaOH 무처리 볏짚 및 4% NaOH 처리 볏짚 모두에서 생효모 배양물 급여에 의하여 in situ 건물 소화율이 유의적으로 증가함을 보여준 것이다(p<0.05). 그리고 볏짚을 효모배양물의 두 가지 농도로 볏짚을 분무 처리하여 in situ 소화율과 볏짚 표면 부착 섬유소분해 박테리아(F. succiongenes, R. flavefaciens, R. albus)의 군집 변화를 측정하였을 때 효모배양물 처리 농도가 증가함에 따라 소화율도 유의적으로 높게 나타났고(p<0.05), 동시에 이들 박테리아의 볏짚 표면 부착 군집도 효모배양물의 처리 농도 증가에 따라 증가 하였다. F. succiongenes과 R. flavefaciens는 배양 12 및 24시간 모두 처리농도에 따라 군락의 수가 유의적으로 증가하였다(p<0.05). 그리고 R. albus도 배양 12 시간 처리농도에 따라 군락의 수가 유의적으로 증가하였고(p<0.05), 24 시간도 처리농도에 따라 증가 경향을 나타냈다. 따라서 본 연구는 효모 첨가는 조사료 소화율을 증진에 확실히 좋은 영향을 주며, 이것은 조사료 표면 부착 섬유소분해 박테리아의 군락 형성 증가에서 기인함을 보여준다고 사료된다.