• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.811-813
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• 2008

To see the effect of magnesium on adhesion to natural zeolites, a series of batch tests were performed in this research. Mixed bacteria were sampled from the digestion tank at a local sewage treatment plant in Seoul. Magnesium-zeolites were synthesized by mixing natural zeolites with 0.096 M, 0.24 M, and 0.48 M of MgCl2 solution. For comparison, manganese and trivalent ferric zeolites were also prepared. Two grams of 0.2 mm $\sim$ 0.3 mm sized zeolites(non-treated, Mg, Mn and Fe(III) treated zeolites) and 20 mL of water were mixed in a Corex 25 mL tube. Five milliliters of culture solution including bacteria was added to the tube. The tubes were equilibrated in a shaking incubator at mesophilic temperature $(30{\pm}2^{\circ}C)$. The bacterial concentrations were measured with a Microluminometer (New Horizons 3550i) and total organic carbon (TOC) spectrophotometer (Multi NC-3100).

• KSBB Journal
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• 제13권6호
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• pp.638-643
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• 1998

An investigation was made to develop new biofilm medium which could be applied to the Sequencing Batch Biofilm Reactor(SBBR) system for enhanced nutrient removal. 21 kinds of polyurethane media were tested fro adhesion ability for nitrifying bacteria. Nitrification rates were also tested by introducing synthetic wastewater containing ammonium-nitrogen to reactors with biofilm media. It was found that Z96-06 medium had higher selective adhension ability for nitrifying bacteria than the other biofilm media. The nitrification rate was 2.21 mg {{{{ { NH}`_{4 } ^{ +} }}}}-N /L$.$h$.$g MLSS when we operated the SBBR system containing Z96-06. Nitrification rate of the SBBR system increased approximately by 30% compared with that of the Sequencing Batch Reactor(SBR) system which did not contain biological carrier.

• 미생물학회지
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• 제37권1호
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• pp.85-91
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• 2001

생물학적 방법으로 토착 미생물에 의해 벤젠과 톨루엔을 효과적으로 분해할 수 있는 토양환경인자의 조건을 조사하기 위해 16가지의 서로 다른 환경의 미소환경(microcosm)을 제작하여 벤젠과 톨루엔 분해실험을 수행하였고, 아울러 분해과정에서 토착미생물의 분포변화를 조사하였다. 그 결과 실험 조건중 토양의 수분 포화도는 30%와 60%이면서 동시에 생물들이 흡착할 수 있는 미생물 흡착제로 활성탄을 1% 첨가한 미소환경(Case 6, Case 7)에서 벤젠과 톨루엔의 분해속도가 가장 빨랐다. 토착토양미생물의 분포변화를 조사한 결과 벤젠과 톨루엔의 분해가 가장 빨리 일어나는 Case 6 와 Case 7에서는 10일 배양 후 total culturable bacteria는 초기 세균 수에 비해 각각 488배와 308배가 증가하였다. 벤젠과 톨루엔 분해세균의 증가 역시 총 세균수가 증가하는 비율로 증가하여 초기 분포를 계속 유지하였고, 벤젠과 톨루엔을 첨가한 미소환경에서 분해 미생물 종의 변화는, 첨가 전 그람음성 세균이 반응 10일 후에는 그람양성 세균이 탈이 분리되었다.

• 대한환경공학회지
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• 제36권12호
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• pp.873-878
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• 2014

본 연구에서는 박테리아 제거를 위한 완속모래여과에서 탄소나노튜브(Carbon Nanotube, CNT)의 적용성을 검토하기 위해서 전자현미경 분석 및 칼럼 실험을 수행하였다. CNT의 형태적 특성을 분석하기 위하여, 주사전자현미경으로 분석한 결과 CNT는 박테리아 부착이 용이한 섬유형태로 응집되어 있었다. CNT의 충진 두께, pH, 이온강도를 달리하며 칼럼 실험을 수행하였다. CNT의 충진 두께가 1 cm, 3 cm, 5 cm로 증가할수록 박테리아 제거율이 44.15%에서 99.95%로 증가하는 것으로 나타났다. 반면, pH가 5.5에서 8.5로 증가할 경우 정전기적 반발력에 의해 박테리아 제거율이 감소하는 경향을 보였다. 이온강도를 0 mM에서 50 mM로 증가하여 칼럼 실험을 수행한 경우 박테리아 제거율이 97.25%에서 70.90%로 감소하였다. 본 연구를 통해 CNT가 오염된 물에 함유되어 있는 박테리아를 처리하는 완속모래여과에 적용 가능한 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제25권6호
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• pp.771-781
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• 2015

To examine if the molecular chaperone DnaK operon proteins of Streptococcus suis type 2 (SS2) are involved in adhesion to host cells, the abundance values of these proteins from the surface of two SS2 strains of different adhesion capability were compared. Their roles in growth and adhesion to human laryngeal epithelial cell line HEp-2 cells were investigated on SS2 strain HA9801 and its mutants with DnaK operon genes partially knocked-out (PKO mutant) under heat stress. The major difference was that DnaJ was more abundant in strain HA9801 than in strain JX0811. Pretreatment of the bacteria with hyperimmune sera to DnaJ, but not with those to other proteins, could significantly reduce SS2 adhesion to HEp-2 cells. PKO of dnaJ g ene resulted in decreased SS2 growth at 37℃ and 42℃, and reduced its adhesion to HEp-2 cells. The wild-type strain stressed at 42℃ had increased expression of DnaJ on its surface and elevated adhesion to HEp-2 cells, which was also inhibitable by DnaJ specific antiserum. These results indicate that the DnaJ of S. suis type 2 is important not only for thermotolerance but also for adhesion to host cells. Because DnaJ expression is increased upon temperature upshift with increased exposure on the bacterial surface, the febrile conditions of the cases with systemic infections might help facilitate bacterial adhesion to host cells. DnaJ could be one of the potential candidates as a subunit vaccine because of its good immunogenicity.

• 치위생과학회지
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• 제19권4호
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• pp.288-293
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• 2019

Background: Dental caries is one of several prevalent oral diseases caused by dental plaque biofilms. This study evaluated the anti-cariogenic effects of a bamboo salt (BS) and sodium fluoride (NaF) mixture on oral bacteria. Methods: The effects of several mixtures of NaF and BS on acid production, growth, and adhesion to glass beads of Streptococcus mutans, and their anti-cariogenic properties were investigated. The growth of S. mutans was measured according to optical density at 3, 6, 9, 12, 15, 18, and 24 hours after treatment using spectrophotometry at a wavelength of 600 nm, while pH was measured using a pH meter. Adhesion of S. mutans was measured according to the weight of glass beads from each group before and after incubation. Gene expression was measured using real-time polymerase chain reaction. Acid production and growth patterns of S. mutans were compared using repeated measures analysis of variance, followed by Scheffe's post-hoc test. The Kruskal-Wallis test was used to compare adhesion, followed by the Mann-Whitney test. Gene expression in the experimental and control samples was compared using the Student's t-test. Results: Growth, acid production, and adhesion of S. mutans were inhibited in all experimental groups. Expression of gft and fructosyltransferase in S. mutans was inhibited in all groups. A mixture of NaF and BS significantly reduced growth, acid production, adhesion, and gene expression of S. mutans compared with the other groups. Conclusion: Results of the present study demonstrated that a mixture of NaF and BS was useful as a mouth rinse in preventing dental caries.

• Macromolecular Research
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• 제16권5호
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• pp.473-480
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• 2008

In this study we investigated bacterial and cell adhesion to poly(propylene carbonate) (PPC) films, that had been synthesized by the copolymerization of carbon dioxide (a global warming chemical) with propylene oxide. We also assessed the biocompatibility and biodegradability of the films in vivo, and their oxidative degradation in vitro. The bacteria adhered to the smooth, hydrophobic PPC surface after 4 h incubation. Pseudomonas aeruginosa and Enterococcus faecalis had the highest levels of adhesion, Escherichia coli and Staphylococcus aureus had the lowest levels, and Staphylococcus epidermidis was intermediate. In contrast, there was no adhesion of human cells (cell line HEp-2) to the PPC films, due to the hydrophobicity and dimensional instability of the surface. On the other hand, the PPC films exhibited good biocompatibility in the mouse subcutaneous environment. Moreover, contrary to expectation the PPC films degraded in the mouse subcutaneous environment. This is the first experimental confirmation that PPC can undergo surface erosion biodegradation in vivo. The observed biodegradability of PPC may have resulted from enzymatic hydrolysis and oxidative degradation processes. In contrast, the PPC films showed resistance to oxidative degradation in vitro. Overall, PPC revealed high affinity to bioorganisms and also good bio-degradability.

• 한국치위생학회지
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• 제20권4호
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• pp.535-543
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• 2020

Objectives: The aim of this study was to investigated the surface roughness and change in the amount of adhesion of Streptococcus mutans to the commercial pit and fissure sealant containing cerium oxide nano particles(CNPs). Methods: The CNPs was incorporated into a commercial pit and fissure sealant at 0-4.0 wt%. Disk Specimens (ϕ 10 mm × 2 mm) were prepared by light polymerization the front and back for 40s. Average surface roughness was measured and Streptococcus mutans adhesion was observed under confocal laser scanning microscopy (CLSM) after 24 hour. Data were statistically analyzed by one-way ANOVA and Tukey HSD^a post-hoc test. Results: Difference of the surface roughness(Ra) between groups was not statistically significant in both non CNPs group and CNPs group(p>0.05). In CNPs group, the amount of S. mutans adhesion was significantly different between control group and decreased in order of CNPs 4.0, CNPs 0.5, CNPs 1.0 and CNPs 2.0(p<0.05). Conclusions: Within the limitation of this study, these aspects of oral bacteria performances suggest potential usefulness of the CNPs incorporation, especially CNPs 1% and 2%, in pit and fissure sealant for inducing antibacterial effect.

• Asian-Australasian Journal of Animal Sciences
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• 제21권11호
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• pp.1604-1609
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• 2008

A series of in vitro and in vivo experiments were conducted to investigate the effects of the mixture of Tween 80 and cellulolytic enzymes (xylanase and cellulase) on total tract nutrient digestibility and rumen cellulolytic bacterial adhesion rates in Holstein steers. Ground timothy hay sprayed with various levels of Tween 80 and cellulolytic enzymes was used as substrates in an in vitro experiment to find out the best combinations for DM degradation. The application level of 2.5% (v/w) Tween 80 and the combination of 5 U xylanase and 2.5 U cellulase per gram of ground timothy hay (DM basis) resulted in the highest in vitro dry matter degradation rate (p<0.05). Feeding the same timothy hay to Holstein steers also improved in vivo nutrient (DM, CP, CF, NDF and ADF) digesibilities compared to non-treated hay (p<0.05). Moreover, Tween 80 and enzyme combination treatment increased total ruminal VFA and concentrations of propionic acid and isovaleric acid with decreased acetate to propionate ratio (p<0.001). However, adhesion rates of Fibrobacter succinogenes and Ruminococcus flavefaciens determined by Real Time PCR were not influenced by the treatment while that of Ruminococcus albus was decreased (p<0.05). The present results indicate that a mixture of Tween 80 and cellulolytic enzymes can improve rumen environment and feed digestibility with variable influence on cellulolytic bacterial adhesion on feed.

• International Journal of Oral Biology
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• 제43권1호
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• pp.37-42
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• 2018

It is noted that Streptococcus mutans (S. mutans) triggers dental caries establishment by two major factors: the synthesis of organic acids, which demineralize dental enamel, and the synthesis of glucans, which mediate the attachment of bacteria to the tooth surface. Therefore, it is noted that the development of a more effective, substantial and safe preventive agent that works against dental caries and periodontal disease is required at this time. For this reason, the present study was designed to investigate the effect of croton seed ethanol extracts on the growth, acid production, adhesion, and insoluble glucan synthesis of S. mutans. In this case, the ethanol extract of croton seed showed concentration dependent inhibitory activity against the growth, acid production and adhesion of S. mutans. Especially, it is important to note that it has produced significant inhibition at the concentration of 0.1 and 0.2 mg/ml as compared to the control group. Moreover, these results suggest that the application of croton seed extract may be considered to be a useful method for the prevention of dental caries.