• Restorative Dentistry and Endodontics
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• 제43권1호
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• pp.1.1-1.8
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• 2018

Objectives: To determine the effect of root canal irrigants on the hydrophobicity and adherence of Staphylococcus epidermidis (S. epidermidis) to root canal dentin in vitro. Materials and Methods: Root dentin blocks (n = 60) were randomly divided into 4 groups based on the irrigation regimen: group 1, saline; group 2, 5.25% sodium hypochlorite (NaOCl); group 3, 5.25% NaOCl followed by 17% ethylenediaminetetraacetic acid (EDTA); group 4, same as group 3 followed by 2% chlorhexidine (CHX). The hydrophobicity of S. epidermidis to root dentin was calculated by cell surface hydrophobicity while the adherence was observed by fluorescence microscopy, and bacteria were quantified using ImageJ software (National Institutes of Health). Statistical analysis of the data was done using Kruskal-Wallis test and Mann-Whitney U test (p = 0.05). Results: The hydrophobicity and adherence of S. epidermidis to dentin were significantly increased after irrigating with group 3 (NaOCl-EDTA) (p < 0.05), whereas in group 4 (NaOCl-EDTA-CHX) both hydrophobicity and adherence were significantly reduced (p < 0.05). Conclusions: The adherence of S. epidermidis to dentin was influenced differently by root canal irrigants. Final irrigation with CHX reduces the bacterial adherence and may impact biofilm formation.

• Food Science and Biotechnology
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• 제14권4호
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• pp.493-497
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• 2005

Probiotics are generally excreted within a few days if their ingestion in feces at the same rate as or even more quickly than a transit marker (meaning not clear). Ability of probiotics to adhere to intestine prolongs their persistence in gastrointestinal tract, allowing them to exert healthful effects longer. Hydrophobicities, zeta potentials, Alcian blue-binding capacities, and sedimentation profiles of Pichia farinosa SKM-1, P. anomala SKM-T, and Galactomyces geotrichum SJM-59 were determined to evaluate characteristic properties of cell surfaces responsible for adhesion. Results of intestinal Caco-2 cell line in vitro and murine intestine in vivo studies revealed these strains exhibit adhesive properties regardless of their cell surface hydrophobicity.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.76.2-76.2
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• 2010

The gas diffusion layer is the key component of the proton exchange membrane fuel cell because it directly affect to the mass transport mechanism and dynamic behavior of the cell. In this study, the effects of GDL aging on the transient response of the PEM fuel cell is systematically investigated using current step transient response analysis under different stoichiometric ratios and humidity conditions. With GDLs aged by the accelerated stress test, the effects of hydrophobicity and structural changes due to carbon loss in the GDL on the transient response of PEM fuel cells are determined. The degraded GDLs that had uneven hydrophobicity distributions cause local water flooding inside the GDL and induce lower and unstable voltage responses after load changes.

• Journal of Microbiology and Biotechnology
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• 제32권1호
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• pp.56-63
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• 2022

This study aims to determine the antibiofilm effect of cell-free supernatant (CFS) of Lactobacillus brevis strains against Streptococcus mutans strains. To study the antibiofilm mechanism against S. mutans strains, antibacterial effects, cell surface properties (auto-aggregation and cell surface hydrophobicity), exopolysaccharide (EPS) production, and morphological changes were examined. The antibiofilm effect of L. brevis KCCM 202399 CFS as morphological changes were evaluated by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM), compared with the control treatment. Among the L. brevis strains, L. brevis KCCM 202399 showed the highest antibiofilm effect on S. mutans KCTC 5458. The antibacterial effect of L. brevis KCCM 202399 against S. mutans KCTC 5458 was investigated using the deferred method (16.00 mm). The minimum inhibitory concentration of L. brevis KCCM 202399 against S. mutans KCTC 5458 was 25.00%. Compared with the control treatment, L. brevis KCCM 202399 CFS inhibited the bacterial adhesion of S. mutans KCTC 5458 by decreasing auto-aggregation, cell surface hydrophobicity, and EPS production (45.91%, 40.51%, and 67.44%, respectively). L. brevis KCCM 202399 CFS inhibited and eradicated the S. mutans KCTC 5458 biofilm. Therefore, these results suggest that L. brevis KCCM 202399 CFS may be used to develop oral health in the probiotic industry.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.297-300
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• 2004

The various microbial tests were performed to determine bioremediation agent capacity for eight strains isolated from the oil contaminated regions. Two tests for isolated strains were conducted such as cell hydrophobicity and emulsifying activity. The biodegradation of SHM (saturated hydrocarbon mixture) and AHM (aromatic hydrocarbon mixture) with the strains also was carried out. The strains having higher cell hydrophobicity and emulsifying activity degraded petroleum oil effectively. The degradation capacity for SHM was represented more than 90% in YS-7 and WLH-1 of isolated strains, and KH3-2 were capable of degrading AHM. Especially, WLH-1 as yeast was shown more than two or three times in the degradation capacity of automobile engine lubricants and the biomonitoring results of contaminated soil for residual oil degrading test showed that the hydrocarbon biodegradation was increased in the second treatment by this strain.

• 한국축산식품학회지
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• 제21권2호
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• pp.133-141
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• 2001

Adherence of probiotic bacteria to intestinal epithelium is found to be the most principal characteristics among the various physiological functionality. This study was conducted to investigate the effect of bifidobacterial growth properties and condition on the Caco-2 cell adherence and to construct a basic data on adherence-related research. Among 20 strains of bifidobacteris tested, when measured by cell surface hydrophobicity(CSH) and cell agglutination(CA), Bifidobacterium bifidum ATCC29521, Bif. adolescentis K8, and Bif. infantis K9 were selected. Using these strains, variations of Caso-2 cell adherence depending upon experimental condition were analyzed. The results obtained are as follows : Even though Bif. bifidum ATCC29521, Bif. adolescentis K8, and Bif. infantis K9 reached more 85% cell surface hydrophobicity there was no significant difference in cell agglutination, when reached 31.54$\pm$0.54mg/ml. By direct count method for adherence, viable cell count of M3, K1, K2, K8, K9 and K10 reached more 100 counts per 100 Caco-2 cells. When Bif. bifidum ATCC29521, Bif. adolescentistis K8, and Bif. infantis K9 were used to compare the adherence depending upon viable cell counts, reaction time, and growth phase, the more viable cell count, and the more adhered cell counts, the less adherence percentage. In addition, there was no difference in adherence percentage of bifidobacteria when bifidobacteria was incubated from 1 to 8 hrs after Caco-2 cells already formed monolayer. Considering of the effect of growth phase of bifidobacteria on adherence variation, all strains showed the highest adherence during the early stage of stationary phase. In conclusion, adherence of bifidobacteria was affected by strain specificity, viable cell count, and growth activity.

• 미생물학회지
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• 제51권3호
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• pp.241-248
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• 2015

프로바이오틱스에 대한 연구는 주로 생균의 효과가 많이 알려져 있지만 가열 처리된 유산균인 사균체의 기능에 대한 연구도 활발히 이루어지고 있다. 본 연구에서는 락토바실러스 아시도필러스 CBT LA1의 사균체의 장관장벽 기능에 대하여 in vitro, in vivo에서 실험하였다. 이를 위하여, 세포표면 소수성 상호작용력(cell surface hydrophobicity), 자가응집력(autoaggregation), 세포에 부착하는 능력(cell adhesion)과 자가응집력(autoaggregation), LPS와의 결합력을 조사하였다. 또한 HT-29 장상피세포에서 LPS로 유도되는 IL-8의 발현을 억제하는 효과를 조사하였다. CBT LA1을 80도에서 121도까지 10분 동안 열을 처리하였을 때, 80도에서 열을 처리한 CBT LA1 사균체가 가장 높은 세포에 부착하는 능력을 보여 주었다. CBT LA1 생균과 비교했을 때, 80도에서 열을 처리한 CBT LA1 사균체는 높은 LPS와의 결합력, 소수성 상호작용력, 자가응집력, HT-29 세포에 부착하는 능력과 IL-8의 발현을 억제하는 능력을 보여주었다. In vivo 실험에서 FITC로 label된 LPS를 투여하였을 때 16시간 후, CBT LA1 사균체를 섭취한 동물의 장관 내 LPS가 가장 많이 제거되었다. 이러한 연구 결과들은 CBT LA1 생균처럼 CBT LA1 사균체도 장관장벽 기능을 가지며 이는, 파마바이오틱스로서 그 가능성을 시사한다.

• Food Science and Biotechnology
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• 제17권2호
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• pp.257-261
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• 2008

Previous studies have suggested a possible correlation between cell surface hydrophobicity (CSH) and stress tolerance in Bifidobacterium. In this study, the relationship was examined between CSH and environmental stress tolerance in Lactobacillus spp. By measuring the adhesion to hexadecane, 2 Lactobacillus fermentum strains- KLB 261 and KLB 231 were found to have high and low CSH, respectively. To measure their tolerance to various stresses, cells were subjected to salt (2 M NaCl), acid (pH 2), $H_2O_2$ (0.01 %, v/v), ethanol (20%, v/v), heat ($60^{\circ}C$), and cold ($-20^{\circ}C$). Compared with KLB 231, the hydrophobic KLB 261 was found to be much more resistant to the various stresses examined. After being subjected to different stresses for a period of time, KLB 261 and KLB 231 showed 50 and 0% survivability in 2 M NaCl, 108.2 and 0.6% in 0.01 %(v/v) $H_2O_2$, 40.2%(v/v), and 3.7% at $60^{\circ}C$ incubation, 4 and 0.6% at $-20^{\circ}C$, 12.9 and 0.1 % in pH 2, 33.8 and 0.2% in 20%(v/v) ethanol, respectively. Autoaggregation test and morphological observation were also conducted in an attempt to explain these differences. These results suggested that high CSH could strengthen the stress tolerance of lactobacilli.

• Journal of Microbiology and Biotechnology
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• 제22권1호
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• pp.25-33
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• 2012

The association of verotoxic E. coli and Acinetobacter spp. with various antibiotic-resistant, diarrhogenic, and nosocomial infections has been a cause for concern worldwide. E. coli and A. haemolyticus isolated on a number of selective media were screened for virulence factors, antibiotic resistance, and transformation of resistance genes. Out of 69 E. coli isolates obtained, 25 (35.23%), 14 (20.30%), and 28 (40.58%) were positive for Vtx1&2, Vtx1, and Vtx2, respectively, 49 (71.015%) for extendedspectrum beta-lactamases (ESBLs), 34 (49.28%) for serum resistance, 57 (82.61%) for cell surface hydrophobicity, 48 (69.57%) for gelatinase production, and 37 (53.62%) for hemolysin production. For the 14 A. haemolyticus isolates, only 2 (14.29%) in each case from all the samples investigated were positive for Vtx1, Vtx2 and Vtx1&2 respectively, 8 (57.14%) for ESBLs, 7 (50.00%) for serum resistance, 11 (78.57%) for cell surface hydrophobicity, 4 (28.57%) for gelatinase production, and 8 (57.14%) for hemolysin production. Although transformation occurred among the E. coli and Acinetobacter isolates (transformation frequency: $13.3{\times}10^{-7}-53.4^{-7}$), there was poor curing of the plasmid genes, a confirmation of the presence of stable antibiotic-resistant genes (DNA concentration between 42.7 and 123.8 ${\mu}g$) and intragenetic transfer of multidrug-resistant genes among the isolates. The isolates were potentially virulent and contained potentially transferable antibiotic resistance genes. Detection of virulence factors, antibiotic resistance genes, and transformation among these isolates is a very significant outcome that will influence approaches to proactive preventive and control measures and future investigations. However, continued surveillance for drug resistance among these bacteria and further investigation of the mechanism of action of their virulence factors are a necessity.

• 한국정보과학회논문지:소프트웨어및응용
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• 제34권7호
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• pp.595-602
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• 2007

본 논문에서는 미지의 아미노산 서열이 신호 펩티다제 I에 의해 절단되는 분비성 단백질인지를 판별하고, 분비성 단백질일 경우에는 절단 위치를 예측하는 방법을 제안한다. 아미노산의 소수성을 이용한 전처리를 수행하여 분비성 단백질의 선도서열인 신호서열의 존재와 절단 위치를 추정한다. 전처리를 통해서 신호서열 아닌 서열을 초기에 제외함으로써 신호서열 예측의 정확도를 높인다. 지지벡터기계를 신호서열의 예측에 효과적으로 적용하기 위해서, 생물학적 정보와 관련된 아미노산 서열간의 거리를 제안한다. 아미노산의 세포내 위치를 예측할 수 있는 소수성 척도와 아미노산의 진화적인 관계를 나타낼 수 있는 치환행렬을 이용하여 아미노산 서열간의 거리를 정의한다. Swiss-Prot release 50 단백질 자료에 대하여 교차타당성 기법을 사용하여 실험한 결과 제안한 방법은 신호서열중에 98.9%를 신호서열로 판별하였고, 88%의 절단위치 예측정확도를 보였다. 기존의 방법과의 비교실험을 통해서 제안한 방법이 신호서열의 예측에 더욱 효과적임을 확인하였다.