• Journal of Ecology and Environment
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• 제33권4호
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• pp.333-341
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• 2010

The objective of our study was to investigate the major reasons for the different growth and visible injury on the needles of black pine growing in Ulsan and Yeocheon industrial complex areas, South Korea. After 12 years of growth, we collected climatic and air pollutant data, and analyzed soil properties and the physiological characteristics of black pine needles. Annual and minimum temperatures in Ulsan were higher than those in Yeocheon from 1996 to 2008. Ozone ($O_3$) was the pollutant in greatest concentration in Yeocheon, and whereas the $SO_2$ concentration in most areas decreased gradually during the whole period of growth, $SO_2$ concentration in Yeocheon has increased continuously since 1999, where it was the highest out of four areas since 2005. Total nitrogen and cation exchange capacity in Yeocheon soil were significantly lower than those of Ulsan. The average growth of black pine in Yeocheon was significantly smaller than that in Ulsan, and the growth of damaged trees represented a significant difference between the two sites. Photosynthetic pigment and malondialdehyde content and antioxidative enzyme activity in the current needles of black pine in Yeocheon were not significantly different between damaged and healthy trees, but in 1-year-old needles, there were significant differences between damaged and healthy trees. In conclusion, needle damage in Yeocheon black pine can be considered the result of long-term exposure to oxidative stress by such as $O_3$ or $SO_2$, rather than a difference in climatic condition or soil properties, and the additional expense of photosynthate needed to overcome damage or alleviate oxidative stress may cause growth retardation.

• Restorative Dentistry and Endodontics
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• 제23권2호
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• pp.550-560
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• 1998

Prevotella intermedia has been known as one of the important bacterial species involved in the endodontic infections and various periodontal diseases. Polyphosphate has been widely used to prevent decomposition of food and known to have an inhibitory effect on the growth of gram positive bacteria. The purpose of this study was to evaluate the effect of poly phosphate on the growth of Prevotella intermedia, a gram negative bacterium. Prevotella intermedia G8GK3(ATCC 49046) was grown in the presence of polyphosphates with different chain lengths. Inhibitory effect of each polyphosphate, which was added at the beginning or at the early exponential growth phase of Prevotella intermedia, was determined by measuring optical density of the bacterial cells at 540nm, viable cells and lysis of Prevotella intermedia. The results from this study were as follows : 1. Poly phosphate inhibited the growth of Prevotella intermedia. 2. The minimum inhibitory concentration(MIC) of poly phosphate appeared to be 0.05%. 3. Polyphosphates with chain lengths of 5 and 65 demonstrated the greatest inhibitory effect on the growth of Prevotella intermedia. 4. Polyphosphate was bactericidal to Prevotella intermedia, demonstrating the growth inhibition of the bacterium. 5. Polyphosphate induced lysis of Prevotella intermedia. The overall results suggest that polyphosphate has a bactericidal effect on Prevotella intermedia, causing the lysis of the bacterium.

• Journal of Applied Biological Chemistry
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• 제48권4호
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• pp.167-169
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• 2005

Crude extract of bioconverted linoleic acid using Pseudomonas aeruginosa PR3 was evaluated for its antibacterial activity against food-borne pathogenic bacteria. Crude extract showed antibacterial activity against four Gram-positive bacteria, Staphylococcus aureus (ATCC 6538), S. aureus (KCTC 1916), Listeria monocytogenes (ATCC 19166), and Bacillus subtilis (ATCC 6633), and one Gramnegative bacterium, Pseudomonas aeruginosa (KCTC 2004), with minimum inhibitory concentrations ranging from 750 to $1,500\;{\mu}g{\cdot}ml^{-1}$. S. aureus and B. subtilis were selected for growth inhibition assays with bioconverted linoleic acid. Major antibacterial effects occurred at lag phase.

• Journal of Microbiology
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• 제45권5호
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• pp.473-477
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• 2007

The in vitro antibacterial activity against antibiotic-resistant Propionibacterium acnes of kaempferol isolated from the Impatiens balsamina alone and in combination with erythromycin or clindamycin antibiotics was investigated. The antibiotic combination effect against antibiotic-resistant P. acnes was studied by checkerboard test. Kaempferol and quercetin demonstrated antibacterial activities against P. acnes. Minimum inhibitory concentrations (MICs) for both compounds were ${\leq}32\;{\mu}g/ml\;and\;{\leq}64{\mu}g/ml$ for clindamycin-sensitive and -resistant P. acnes, respectively. The four combination formulations (kaempferol and either erythromycin or clindamycin; quercetin and either erythromycin or clindamycin) exhibited a synergic inhibition of P. acnes growth. The combination of kaempferol with quercetin showed an indifferent effect. The combination of clindamycin with kaempferol or quercetin showed a greater synergic effect than that of erythromycin with kaempferol or quercetin. Thus, these combinations demonstrated the potential to treat acne.

• 한국식품과학회지
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• 제30권3호
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• pp.672-679
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• 1998

고삼 75% 에탄올 추출물과 클로로포름 분획물을 첨가하여 몇가지 식중독 미생물의 증식억제 양상과 분리된 유효 물질의 구조를 확인하였다. 이 분획물의 항균 효과를 시험한 결과 Listeria monocytogenes (ATCC 19111, 19112, 19113, 19114 및 15313)에 대한 최소 증식억제 농도가 각각 $50{\sim}500\;ppm$과 50 ppm 이하로 확인되었다. 항균 활성을 보인 클로로포름 분획물을 silica gel column chromatography로 연속 2회 정제하여 얻은 황색 분말의 항균 활성 소획분 S-10-6은 L. monocytogenes 5 균주, Bacillus subtilis 및 Staphylococcus aureus에 대해서는 10 ppm 농도에서 뚜렷한 증식억제 효과를 보였으며 특히 L. monocytogenes 5균주에 대해서는 $30{\sim}50\;ppm$ 수준에서 살균 효과가 인정되었으나 E. coli 경우 100 ppm 농도에서도 증식억제 효과가 없었다. 항균 활성을 보인 소획분(S-10-6)을 IR, $^1H-NMR$ 및 $^{13}C-NMR$로 구조를 동정한 결과 flavanone 화합물의 하나인 kushenol F로 확인되었다.

• 약학회지
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• 제54권2호
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• pp.106-111
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• 2010

The chemical structures of eight compounds purified from two plants (Polygala tenuifolia Willdenow and Dioscorea batatas Decene) were determined and their anti-microbial activity against three microbial strains (Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans) was tested. The three micro organisms were cultured in 96-well plates or Petri dishes without (control) or with the eight compounds added at concentrations of 100 to 0.01 ${\mu}M$ (wt/vol). The growth of the microorganisms in the medium was examined after a 24-h incubation. The inhibitory effect of each compound on the growth of the microorganisms was calculated from the optical density measured at 595 nm, turbidity, and size of the inhibition zone around the treated paper disc. The minimum inhiitory concentration (MIC) of compounds 4 to 7 against S. aureus was 0.08, 0.05, 1.3 and 0.02 ${\mu}M$, respectively, and 0.09, 0.1, 0.2 and 100 ${\mu}M$ against C. albicans. The $IC_{50}$ (50% inhibition) values of compounds 5 and 6 were 3.1 and 6.4 ${\mu}M$ against S. aureus, respectively, and 10 and 2.4 ${\mu}M$ against C. albicans. Therefore, compounds 4 to 6 were the most potent anti-microbial agents among the eight compounds tested.

• 한국미생물·생명공학회지
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• 제46권1호
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• pp.40-44
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• 2018

Gram 양성세균의 생육을 억제하는 세균을 청주시 무심천 토양에서 분리하였으며, 16S rRNA 유전자 염기서열 분석 결과 Pseudomonas otitidis PS로 동정하였다. PS 균주는 0.5%의 glucose가 포함된 1% soybean meal 배지에서 2차 대사 산물로서 최대 약 0.1%의 수율로 항생물질을 생산하였다. 항생물질 성분은 ethyl acetate로 추출하였으며, Staphylococcus aureus KCTC 1261에 대한 minimum inhibitory concentration은 $2{\mu}g/ml$이었다. 이 성분은 siderophore 활성을 띠어서 chrome azurol S 평판배지에서 주황색 halo를 나타내었으며, 철이 제거되면 생육 억제 효과는 감소하였다. Ascorbic acid 같은 환원제를 첨가하거나 혐기적 환경에서는 항생물질 활성을 잃으므로 PS 항생물질은 활성산소를 방출하여 bactericidal activity를 갖는 것으로 보인다.

• 한국식품저장유통학회지
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• 제5권3호
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• pp.299-304
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• 1998

전통민속주 제조에 널리 사용되어온 국화꽃잎에서 에탄올 추출하여 식품부패에 관련된 미생물을 대상으로 항균활성을 검색하고 에탄올 추출물의 농도별 항균활성과 최저 생육저해 농도를 조사하였다. 국화 에탄올 추출물의 항균활성은 산국이 B. subtilis에 대해 항균활성이 높게 나타난 반면, 소국은 E.coli에 대한 항균활성이 산국보다 다소 높게 나타났다. 8종의 부패균에 대한 에탄올 추출물의 항균활성은 산국이 소국에 비하여 높게 나타났으며, 산국 에탄올추출물의 최소저해농도는 60-70${\mu}\ell$/ml로 나타났다. 산국 에탄올추출물은 그람양성세균에서 보다 그람음성세균에 대한 항균활성이 다소 높았으나, 100${\mu}\ell$ 농도에서는 그람음성 및 양성 세균 모두 생육이 크게 저해되었다. 따라서 전통민속주의 보존효과 측면에서 산국 에탄올추출물이 우수한 것으로 나타났다.

• 한국치위생학회지
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• 제17권3호
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• pp.493-504
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• 2017

Objectives: This study aimed to find out the antimicrobial activities of Ramaria botrytis (Fr.) extracts against oral pathogens. Methods: The antimicrobial activities of Ramaria botrytis (Fr.) extracts were evaluated against oral pathogens by the disc diffusion assay, and the minimum inhibitory concentrations (MICs) of ethyl acetate extracts were determined by broth dilution method. The strains used in this study were Staphylococcus aureus, Streptococcus mutans, Streptococcus sanguinis, Streptococcus sobrinus, Streptococcus anginosus, Streptococcus ratti, Streptococcus criceti, Actinomyces israelii, Actinomyces viscosus and Aggregatibacter actinomycetemcomitans. Results: The ethyl acetate extract of Ramaria botrytis (Fr.) effectively inhibited the growth of oral bacteria compared with acetone or ethanol extract. The ethyl acetate extract exhibited MIC values ranging from 3.75 to 15.00 mg/ml, and it showed antimicrobial activity against both Gram-positive and negative oral bacteria. Conclusions: The ethyl acetate extracts from Ramaria botrytis (Fr.) showed the antimicrobial activities against ten oral bacteria. Thus, the extract of Ramaria botrytis (Fr.) may be considered as an effective natural antimicrobial agent for the prevention of oral pathogens.

• 대한수의학회지
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• 제56권2호
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• pp.103-108
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• 2016

Salmonellosis is a major bacterial zoonosis that causes self-limited enteritis in animals and foodborne disease and typhoid fever in humans. Recently, multi-drug-resistant strains of Salmonella spp. have increased and caused more serious problems in public health. The present study investigated the antibacterial effects of egg-white lysozyme (EWL) against Salmonella (S.) Typhimurium and the therapeutic effects of EWL for murine salmonellosis. Evaluation of the antibacterial effects of EWL against S. Typhimurium revealed a minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of EWL of 6.25 and $300{\mu}g/mL$, respectively. In the bacterial growth inhibition test, EWL at 300 (p < 0.05) and $600{\mu}g/mL$ (p < 0.01) significantly inhibited the growth of S. Typhimurium at 4 h post-incubation. EWL administration at MIC (LYS-1), MBC (LYS-2) and $2{\times}MBC$ (LYS-3) for 14 days resulted in mortality of mice infected with S. Typhimurium of 70, 40 and 10%, respectively, while that of control mice (CON) was 90%. Counts of S. Typhimurium in murine spleens were significantly lower in LYS-2 and LYS-3 than CON (p < 0.05). The results of this study indicate that EWL has the potential for treatment of ICR mice infected with S. Typhimurium.