• Journal of Microbiology and Biotechnology
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• 제5권6호
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• pp.346-352
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• 1995

For isolation of antibiotic-producing bacteria antagonistic to Fusarium oxysporum, a total of 327 microorganisms were screened from sesame-growing soils collected at various locations in Korea by the modified Herr's triple-agar-Iayer technique. Among the 36 bacterial isolates further screened by the dual culture test on tryptic soy agar, 10 were tested to show their antagonistic activity against 14 plant pathogenic fungi. Bacterial culture filtrates were shown either to inhibit some phytopathogenic fungal growth or to suppress F. oxysporum infection of sesame plants maintained in the green house. An isolate, B23, with the most prominent antagonistic activity was identified as Bacillus subtilis.

• Restorative Dentistry and Endodontics
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• 제24권2호
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• pp.426-429
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• 1999

When the tooth avulsion occur in accidents the drying damage to the periodontal ligament has extremely detrimental effects on healing. Pulp necrosis always occurs after an avulsion injury, but revascularization can only take place in teeth with immature apexes. Therefore complications after avulsion injuries are common, and treatment must be carried out in a timely and correct fashion to prevent or limit these complications. Every effort should be made to replant the tooth within the first 15 to 20 minutes. If doubt exists that the tooth can be replanted adequately, the tooth should quickly be stored in an appropriate medium until the patient can get to the dental office for replantation. A complication of inflammatory root resorption is occurred by bacterial infection of periodontal ligament and dental pulp. Therefore aseptic endodontic treatment must be carried out in a timely and systemic antibiotics given at the time of replantation and before endodontic treatment are effective in preventing bacterial invasion. Further studies are needed to establish the clinical importance of preparation of the socket and root.

• Journal of Microbiology and Biotechnology
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• 제16권6호
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• pp.855-862
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• 2006

Hexavalent chromium ($Cr^{6+}$) is a highly harmful pollutant, which can be detoxified and precipitated through reduction to $Cr^{3+}$. Bacillus megaterium TKW3 previously isolated from chromium-contaminated marine sediments was capable of reducing $Cr^{6+}$ in concomitance with metalloids ($Se^{4+}$, $Se^{6+}$, and $As^{5+}$). Notwithstanding approximately 50% inhibition, it was the first report of simultaneous bacterial reduction of $Cr^{6+}$ and $Se^{4+}$ (to elemental Se). No significant difference was observed among electron donors (glucose, maltose, and mannitol) on $Cr^{6+}$ reduction by B. megaterium TKW3. The reduction was constitutive and determined to be non-plasmid mediated. Peptide mass fingerprints (PMF) revealed a novel aerobic membrane-associated reductase with $Cr^{6+}$-induced expression and specific reductive activity (in nmol $Cr^{6+}$/mg protein/min) of 0.220 as compared with 0.087 of the soluble protein fraction. Respiratory inhibitor $NaN_3$ did not interfere with the reductase activity. Transmission electron microscopy with energy dispersive X-ray (TEM-EDX) analysis confirmed the aggregation of reduced chromium along the intracellular membrane region. Future identification of the N-terminal amino acid sequence of this reductase will facilitate purification and understanding of its enzymatic action.

• Tuberculosis and Respiratory Diseases
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• 제70권6호
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• pp.490-497
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• 2011

Background: It is difficult but important to differentiate between bacterial and viral infections, especially for respiratory infections. Hence, there is an ongoing need for sensitive and specific markers of bacterial infections. We investigated novel biomarkers for discriminating community acquired bacterial pneumonia from 2009 H1N1 influenza A infections. Methods: This was a prospective, observational study of patients with community acquired bacterial pneumonia, 2009 H1N1 Influenza A infection, and healthy controls. Serum samples were obtained on the initial visit to the hospital and stored at $-80^{\circ}C$. We evaluated CRP (C-reactive protein), PCT (procalcitonin), LBP (lipopolysaccharide-binding protein) and copeptin. These analytes were all evaluated retrospectively except CRP. Receiver operating characteristic curve (ROC) analyses were performed on the resulting data. Results: Enrolled patients included 27 with community acquired bacterial pneumonia, 20 with 2009 H1N1 Influenza A infection, and 26 who were healthy controls. In an ROC analysis for discriminating community acquired bacterial pneumonia from 2009 H1N1 influenza A infection, areas under the curve (AUCs) were 0.799 for CRP (95% Confidence interval [CI], 0.664~0.934), 0.753 for PCT (95% CI, 0.613~0.892) and 0.684 for LBP (95% CI, 0.531~0.837). Copeptin was not different among the three groups. Conclusion: These findings suggest that serum CRP, PCT and LBP can assist physicians in discriminating community acquired bacterial pneumonia from 2009 H1N1 influenza A infection.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2005년도 International Meeting of the Microbiological Society of Korea
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• pp.202.1-202
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• 2005

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2005년도 International Meeting of the Microbiological Society of Korea
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• pp.191.4-191
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• 2005

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.399-402
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• 2002

Industrial wastewater with high ammonium concentration was treated in batch biological systems which was a modified Ludzack- Ettinger process. Up to 78% conversion of $NH_4\;^+-N$ to $NO_x\;^--N$ was achieved in batch culture condition. Under anoxic condition with methanol as the carbon source, the denitrifiers decreased $NO_x\;^--N$ concentration from 608 mg/L to 5.6 mg/L in 22 d. As well as anoxic denitrification of $NO_x\;^-$ to $N_2$, dissimilatory nitrate reduction to ammonium also occurred under the condition as respiratory denitrification.

• Journal of Microbiology and Biotechnology
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• 제25권12호
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• pp.2090-2099
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• 2015

Recently, the cardiovascular disease has been widely problematic in humans probably due to fibrin formation via the unbalanced Western style diet. Although direct (human plasmin) and indirect methods (plasminogen activators) have been available, bacterial enzyme methods have been studied because of their cheap and mass production. To detect a novel bacterial fibrinolytic enzyme, 111 bacterial strains with fibrinolytic activity were selected from kimchi. Among them, 14 strains were selected because of their stronger activity than 0.02 U of plasmin. Their 16S rRNA sequence analysis revealed that they belong to Bacillus, Leuconostoc, Propionibacterium, Weissella, Staphylococcus, and Bifidobacterium. The strain B. subtilis ZA400, with the highest fibrinolytic activity, was selected and the gene encoding fibrinolytic enzyme (bsfA) was cloned and expressed in the E. coli overexpression system. The purified enzyme was analyzed with SDS-PAGE, western blot, and MALDI-TOF analyses, showing to be 28.4 kDa. Subsequently, the BsfA was characterized to be stable under various stress conditions such as temperature (4-40oC), metal ions (Mn²⁺, Ca²⁺, K²⁺, and Mg²⁺), and inhibitors (EDTA and SDS), suggesting that BsfA could be a good candidate for development of a novel fibrinolytic enzyme for thrombosis treatment and may even be useful as a new bacterial starter for manufacturing functional fermented foods.

• 한국어류학회지
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• 제19권2호
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• pp.83-87
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• 2007

어류 에드워드감염증에 대한 예방 재조합 ghost 백신을 개발하기 위한 연구의 일환으로 어류 병원성 세균인 Edwardsiella trada를 대상으로 플라스미드 형질전환을 실시하고 형질전환 안정성을 평가하였으며, 형질 도입된 재조합 ghost 세균의 E-lysis 유전자 발현을 분석하였다. E. tarda를 대상으로 한 ghost 유도는 대장균에 비해 상대적으로 장시간의 반응 시간이 요구되며 lysis의 개시가 지연된 점을 고려 시 발현된 E protein의 용해 능력 또는 E-gene의 전사발현 양이 E. tarda에서 다소 약화되는 것으로 나타났다. 그러나 대장균에 비해 ghost 유도 속도가 다소 낮음에도 불구하고 반응이 완성되었을 시점에서의 E. tarda의 ghost 효율은 대장균과 전혀 차이가 없이 99.99% 이상의 유도효율을 나타내었다.

• Elastomers and Composites
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• 제50권3호
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• pp.223-230
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• 2015

Bacterial infection is one of the most common and universal cause of disease spreading associated with medical and surgical environment. Antimicrobial function of plasticized polyvinyl chloride (PVC) will be useful for making hygienic environments. Here, we synthesized the PVC composite by the addition of inorganic bacteriocide containing silver, zinc and zeolite. And we investigated the growth inhibition rate for Staphylococcus aureus and Klebsiella pneumoniae which were analyzed in the presence of PVC composite with different doses of inorganic bacteriocide (1~15 wt%). Bacterial proliferation was significantly inhibited by 3 wt% of inorganic bacteriocide containing PVC composite. And we found the inhibition of bacterial biofilm formation by 5 wt% of inorganic bacteriocide containing PVC composite by the observation of scanning electron microscopy (SEM). Our data suggested that the antimicrobial effect of inorganic bacteriocide was caused by disturbing the bacterial biofilm formation.