• KSBB Journal
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• 제13권2호
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• pp.119-124
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• 1998

Twelve bacterial strains capable of growing on phenol minimal medium were isolated from iron foundry activated sludge by enrichment culture, and amount them, one isolate which was the best in cell growth and phenol degradation was selected and identified as Acinetobacter junii POH. The optimal temperature, initial pH and phenol concentration in the above medium were 3$0^{\circ}C$, 7.5 and 1000 ppm, respectively. Cell growth of Acinetobacter junii POH dramatically increased 20 hrs cultivation-time and reached a almost stationary phsae 40 hrs cultivation-time then phenol was degraded about 98%. Cell growth was inhibited y phenol at concentrations over 1500 ppm. The isolate was resistant to several antibiotics as well as various heavy metal ions. The growth-limiting log P value of Acinetobacter junii POH on organic solvents was 2.9 in the LB medium. Therefore, it is suggested that Acinetobacter junii POH could be effectively used for the biological treatment of wastewater containing the presence of heavy metal ions and organic solvents.

• 한국환경보건학회지
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• 제23권4호
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• pp.33-38
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• 1997

Four bacterial strains able to degrade dichlorobenzene as the sole source of carbon and energy were isolated from soil by selective enrichment culture, and among them, one isolation was the best in the cell growth and identified as Pseudomonas sp. DCB3 by its morphology and physiological properties. Cell growth dramatically increased in a minimal medium containing 500ppm of dichlorobenzene was not detected any more at 72 hours after cultivation. The optimal temperature and initial pH for the growth of the isolated strain were 30$\circ$C and 7.0, respectively. Cell growth was increased by supplementing $(NH_2)_2CO$ and 50 ppm yeast extract as additional nutrients. Therefore, it was suggested that Pseudomonas sp. DCB3 could be effectively used for the biological treatment of wastewater containing dichlorobenzene.

• 식물병연구
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• 제21권4호
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• pp.290-296
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• 2015

Ralstonia solanacearum에 의해 발생하는 토마토 풋마름병에 대한 효율적인 저항성 검정법을 확립하고자 감수성 및 저항성 토마토 9개 품종의 접종 방법, 토마토의 생육시기, 접종 농도 및 접종 후 재배 온도에 따른 풋마름병 발생을 조사하였다. 상처없이 풋마름병균 현탁액을 관주하여 접종한 토마토는 뿌리에 scalpel로 인위적인 상처를 내고 접종한 토마토보다 감수성과 저항성 반응이 더 분명하게 나타났다. 그리고 저항성 토마토인 'Hwaii7996'은 실험한 모든 조건 즉 접종하는 토마토의 생육 시기(3, 6, 8, 10엽기), 접종 농도($OD_{600}=0.1-0.4$), 접종 후 재배온도(25, 30, $35^{\circ}C$)에서 고도의 저항성을 보였다. 그러나 감수성 품종들은 6엽기와 8엽기 토마토는 각각 3.7과 3.9의 높은 발병도를 보였으나, 3엽기와 10엽기 토마토는 각각 2.1과 0.5로 풋마름병 발생이 낮았다. 그리고 풋마름병균을 접종하고 25, 30, $35^{\circ}C$에 재배하였을 때, 감수성 품종들은 $25^{\circ}C$에서는 0.5 이하의 낮은 발병도를 보였으나 30와 $35^{\circ}C$에서는 각각 3.1과 2.9 이상의 높은 발병도를 나타냈다. 한편, 실험한 감수성 토마토 품종들은 접종원 농도($OD_{600}=0.1-0.4$)와 관계없이 높은 감수성을 나타냈다. 이상의 결과로부터 토마토 풋마름병에 대한 효율적인 저항성 검정 방법으로 접종 1주일 전에 이식하여 재배한 8엽기 토마토 유묘를 사용하여 뿌리에 상처를 내지 않고 풋마름병균 현탁액($OD_{600}=0.4$)을 토양 리터 당 50 ml씩 관주하여 접종하고, $30^{\circ}C$ 생육상에서 하루 12시간씩 광을 조사하면서 12-13일 동안 재배하는 것을 제안하고자 한다.

• Journal of Microbiology and Biotechnology
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• 제15권1호
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• pp.118-124
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• 2005

In this research, we examined the effect of NaCl on the growth, energy metabolism, and proton motive force of Halomonas salina, and the effect of compatible solutes on the bacterium growing in the high salinity environment. H. salina was isolated from seawater and identified by 16srDNA sequencing. The growth of H. salina was not enhanced by the addition of external compatible solutes (choline and betaine) in the high salinity environment. The resting cells of H. salina absorbed more glucose in the presence of 2.0 M NaCl than in its absence. H. salina did not grow in the medium with either KCl, RbCl, CsCl, $Na_2SO_4$, or $NaNO_3$, in place of NaCl. The optimal concentration of NaCl for the growth of H. salina ranged from 1.4 M to 2.5 M, and the growth yield was decreased in the presence of NaCl below 1.4M and above 2.5M. The activity of isocitrate dehydrogenase, pyruvate dehydrogenase, and malate dehydrogenase of H. salina was not inhibited by NaCl in in vitro test. The proton translocation of H. salina was detected in the presence of NaCl only. These results indicate that NaCl is absolutely required for the normal growth and energy metabolism of H. salina, but the bacterial growth is not enhanced by the compatible solutes added to the growth medium.

• The Plant Pathology Journal
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• 제20권3호
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• pp.172-176
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• 2004

Bacterial isolates TRL2-3 and TRK2-2 showing anti-fungal activity in vitro test against some plant pathogens were identified as Pseudomonas putida and Micrococcus luteus, respectively. Pre-treatment with both bacterial isolates at the concentration 1.0$\times$ $10^7$ and $10^6$cfu/ml in the rhizosphere could trigger induced systemic resistance in the aerial part of cucumber plants against anthracnose caused by Colletotrichum orbiculare. However, the pre-treatment with the higher concentration at 1.0 $\times$ $10^8$ cfu/ml of both isolates could not induce resistance after challenge inoculation with C. orbiculare. As a positive control, the treatment with DL-3 amino butyric acid caused a remarkable reduction of disease severity whereas the lesions on the leaves of untreated plants developed apparently after the fungal inoculation. From these results, it was recomended that disease control using both bacterial isolates inducing systemic resistance in the field where chemical application is forbid.

• 대한통합의학회지
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• 제6권3호
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• pp.131-139
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• 2018

Purpose : The study objective was to assess the antibacterial activity of essential oil of basil against S. mutans and P. gingivalis and to explore its potential to prevent dental caries and peridontal disease. Method : Essential oil of basil, extracted using steam distillation, was diluted with triple distilled water and Tween 20 to generate samples at various concentration, that is 30%, 50%, and 70% (v/v). Strains of S. mutans and P. gingivalis were incubated in the medium under anaerobic condition. Broth microdilution susceptibility testing and plate incubation diffusion were utilized to determine the minimum inhibitory concentration (MIC) and to measure antibacterial activity, respectively. Result : An upsurge in antibacterial activity was seen to correlate with and increase in the concentration used for both bacterial strains, but was more significant with S. mutans. A statistically significant growth inhibition effect and reduction in the number of colonies was also observed with both strains dependent on the concentration used following 24 hours of incubation. Conclusion : Thus, the current study finding was that essential oil of basil was effective against dental caries and periodontal disease and could be used in dentifrice to help prevent oral disease.

• Journal of Microbiology and Biotechnology
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• 제14권6호
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• pp.1200-1210
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• 2004

Metabolic flux analysis was established by adapting previous stoichiometric model developed during growth with cellulose to cell grown with cellobiose for further direct comparison of the bacterial metabolism. In carbon limitation with cellobiose, a shift from acetate-ethanol fermentation to ethanol-lactate fermentation is observed and the pyruvate overflow is much higher than with cellulose. In nitrogen limitation with cellobiose, the cellodextrin and exopolysaccharide overflows are much higher than on cellulose. In carbon and nitrogen saturation with cellobiose, the cellodextrin, exopolysaccharide, and free amino acids overflows reach the highest levels observed but all remain limited on cellulose. By completely shunting the cellulosome, the use of cellobiose allows to reach much higher carbon consumption rates which, in return, highlights the metabolic limitation of C. cellulolyticum. Therefore, the physical nature of the carbon source has a profound impact on the metabolism of C. cellulolyticum and most probably of other cellulolytic bacteria. For cellulolytic bacteria, the use of soluble carbon substrate must carefully be taken into consideration for the interpretation of results. Direct comparison of metabolic flux analysis from cellobiose and cellulose revealed the importance of cellulosome, phosphoglucomutase and pyruvate-ferredoxin oxidoreductase in the distribution of carbon flow in the central metabolism. In the light of these findings, future directions for improvement of cellulose catabolism by this bacterium are discussed.

• 대한한의학회지
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• 제41권3호
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• pp.55-65
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• 2020

Objectives: This study aimed to evaluate the toxicity of CP pharmacopunture using bacterial reverse mutation test. Methods: To determine the mutagenic potential of CP pharmacopunture, histidine requiring Salmonella typhimurium (TA98, TA100, TA1535, and TA1537) and tryptophan requiring Escherichia coli (WP2uvrA, pKM101) strains were used. The negative (normal saline solution) and positive (Sodium azide, 2-Nitrofluorene, 2-Aminoanthracene, 9-Aminoacridine, and 4-Nitroquinoline N-oxide) control groups were used. To determine the dose levels of the main study, a dose range-finding study was conducted. Results: As a results of the dose range-finding study, the growth inhibition by CP pharmacopunture was not evident at any dose levels in the absence and presence of metabolic activation. As a results of the main study, the mean number of revertant colonies was less than twice when compared to the negative control values at all dose levels of the CP pharmacopuncture in the presence and absence of metabolic activation, showing no dose-related increase. In the positive control group, the number of revertant colonies was markedly increased by more than twice when compared to the negative control group. Conclusion: According to the results of this study, CP pharmacopunture did not show any signs of mutagenic potential.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2000년도 추계 학술대회
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• pp.125-139
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• 2000

The differential enhanced degradation of cis- and trans-1,3-D was observed in the previous two studies performed by Ou et al. (1995) and especially Chung et al. (1999). This study was initiated to investigate the involvement of microorganisms in the differential enhanced degradation of the chemicals. As expected, microorganisms were responsible for the enhanced degradation of the chemicals. A mixed bacterial culture capable of degrading 1,3-D was isolated from an enhanced soil sample collected from a site treated with 1,3-D. Similar to the enhanced soil, the mixed culture degraded trans-1,3-D faster than cis-1,3-D. This mixed culture could not utilize cis- and trans-1,3-D as a sole source of carbon for growth. Rather, a variety of second substrates were evaluated to stimulate the differential enhanced degradation of the two isomers. As a result, the mixed culture degraded cis- and trans-1,3-D only in the presence of a suitable second substrate. Second substrates that had the capacity to stimulate the degradation included soil leachate, tryptone, tryptophan, and alanine. Other substrates tested, including soil extract, glucose, yeast extract, and indole (ailed to stimulate the degradation of the two isomers. Therefore, it appeared that the degradation of cis- and trans-1,3-D was a cometabolic process. The mixed culture was composed of four morphologically distinctive bacterial colonies.

• 한국환경과학회지
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• 제12권8호
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• pp.847-852
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• 2003

It was examined carefully that the bacterial die-off between Chlorella vulgaris and E. coli. W3110 was tested through adding TOC (total organic carbon) with the lab-scaled continuous river water flow system (CRWFS). Artificial synthetic wastewater was applied at two levels of organic carbon concentration; 1,335 mg/l in treatment type 1 and 267 mg/l in type 2. In both types, the population densities of Chlorella vulgaris were similar in a maximum 8.25 ${\times}$ 10$\^$6/ cells/ml (type 1) and 6.925 ${\times}$ 10$\^$6/ cells/ml (type 2). The maximum densities of E. coli. W3110 were 2.0 ${\times}$ 10$\^$8/ colony forming unit (CFU)/ml in type 1 and 3.9 ${\times}$ 10$\^$8/ CFU/ml in type 2. The densities increased for 11 days in type 1 and 4 days in type 2, then decreased rapidly till the 35th day, then slightly increased again. This trend was prominent in type 2. It implied that a wider range of nutrients was required in the growth of heterotrophic bacteria in type 2 than in type 1. We could not expect successful bacterial die-off if the wastewater retention time was not furnished sufficiently.