• 한국미생물·생명공학회지
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• 제20권3호
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• pp.249-256
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• 1992

국내에서 구입 가능한 주요 식이 소재로부터 장내의 대표적인 유해균인 Clostridium perfringens의 생육을 억제시키는 소재를 탐색한 결과 감자즙에서 강력한 항균활성을 발견하였다. 감자즙 중 70% 황산암모늄용액에서 침전되는 단백질성 물질이 항균활성을 나타낸 것으로 밝혀졌으며, 이 감자단백질은 pH 4~10 사이에서는 안정하나 $60^{\circ}C$에서 10분간의 열처리로 그 활성이 소실되었다.

• Journal of Microbiology and Biotechnology
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• 제20권5호
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• pp.875-880
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• 2010

Bacterial enoyl-ACP reductase (FabI) has been demonstrated to be a novel antibacterial target. In the course of our screening for FabI inhibitors, we isolated two methyl-branched fatty acids from Streptomyces sp. A251. They were identified as 14-methyl-9(Z)-pentadecenoic acid and 15-methyl-9(Z)-hexadecenoic acid by MS and NMR spectral data. These compounds inhibited Staphylococcus aureus FabI with $IC_{50}$ values of 16.0 and $16.3\;{\mu}M$, respectively, but did not affect FabK, an enoyl-ACP reductase of Streptococcus pneumonia, at $100\;{\mu}M$. Consistent with their selective inhibition for FabI, they blocked intracellular fatty acid synthesis as well as the growth of S. aureus, but did not inhibit the growth of S. pneumonia. Additionally, these compounds showed reduced antibacterial activity against fabI-overexpressing S. aureus, compared with the wild-type strain. These results demonstrate that the methylbranched fatty acids show antibacterial activity by inhibiting FabI in vivo.

• 미생물학회지
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• 제27권3호
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• pp.285-290
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• 1989

한국에서 분리한 비유황 광합성 세균 Rhodospirillum rubrm KS-301 생장에 대하여 논 잡초제로 널리 쓰이는 butachlor(제품명 Machete)의 영향을 본 것이다. 실제 논에서 사용되고 있는 농노인 $10^{-3}$에서도 균의 생장은 이루어졌고 $10^{-2}$M의 농도에서 억제되어 다른 생물체보다 높은 저항력을 가지는 것으로 나타났다. 더욱이 pyruvate를 탄소원으로 하여 질소고정 상태로 배양했을 때 butachlor를 처리한 실험군에서 미약하나마 오히려 생장이 촉진되었다. (1%). 전자현미경으로 내부막조직을 관찰한 결과 Rhodospirillum rubrum의 전형적인 vesicular type이 tubular type으로 변형된 것으로 보아 제초제의 흡수가 간접 확인되었다. 또한 pH가 알칼리 조건일 때 질소고정상태에서 균생장에 대한 제초제의 저해력이 떨어지는 것으로 나타났다.

• 한방안이비인후피부과학회지
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• 제22권1호
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• pp.100-107
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• 2009

Objective : The purpose of this study is to investigate the antibacterial activity of Saussurea lappa for the applications of herb-based extracts to both cosmetic and medicinal industries. Methods : Antibacterial activity of ethanol extract of Saussutes lappa (ESL) was assessed using agar diffusion and broth dilution methods, and determined by whether clear zone was formed around paper disc and in terms of the size (mm) of clear zone, Results : ESL provided activity against Staphylococcus aureus KCTC 1927 in concentration of 1 mg/ml with an clear zone of 16 mm, and showed an activity against Staphylococcus epidermids KCTC 1917 in concentration of 1 mg/ml with an clear zone of 18mm. Moreover, the minimum inhibitory concentration (MIC) of ESL against S. sureus and S. epidermidls were 1 mg/ml for both bacterial species. However, ESL showed no growth inhibition against Pseudomonas aeruginosa KCTC 12513, Enterobactet aerogenes KCTC 2190, Escherichia coli KCTC 2571, Salmonella typhimurium KCTC 1925 and Propionibacterium acnes KCCM 41747. Conclusions : Antibacterial activity of ESL against Staphylococcus sureus and Staphylococcus epidermids causing eye and skin diseases was proved. The result suggest that ESL may be useful as a natural preservative on behalf of synthetic preservatives.

• 한국미생물·생명공학회지
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• 제13권3호
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• pp.203-207
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• 1985

장내세균 Bifidobacterium longum에 의한 대장균성 설사증의 주 원인균인 E. coli $A_2$의 생육저해를 혐기적 조건에서 조사한 결과를 요약하면 다음과 같다. 한국 성인으로부터 분리ㆍ동정한 Bif. longum SKD-2001은 E. coli $A_2$의 생육을 저해시키는 생육저해 작용을 가지고 있었다. Bifidus 균제제에서 분리ㆍ동정한 Bif. longum SKD-2004도 역시 E. coli $A_2$의 생육을 저해하였다. pH가 저하됨에 따라서 생육저해가 있는 것으로 보아 E. coli $A_2$의 생육저해는 Bif., longum이 생산한 lactic acid와 acetic acid에 의해 배양액의 pH가 저하됨으로써 나타나는 것으로 사료되었다.

• The Plant Pathology Journal
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• 제27권1호
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• pp.78-84
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• 2011

Antagonistic rhizobacteria, more specifically fluorescent pseudomonads and certain species of Bacillus, are known as biocontrol agents of fungal root diseases of agronomic crops. In this study, 144 bacteria were isolated from cucumber rhizosphere and screened as potential biological control agents against Phytophthora drechsleri, the causal agent of cucumber root rot, in vitro condition. Non-volatile compounds of 23 isolates showed noticeable inhibition zone (> 30%) against P. drechsleri, whereas volatile compounds of 7 isolates could prevent more than 30% of the mycelial growth of the fungus. All promising isolates, except of Pseudomonas flourescens V69, promoted significantly plant growth under in vitro condition. P. flourescens CV69 and V11 exhibited the highest colonization on the root. Results of the greenhouse studies showed that a reduction in disease incidence by use of some strains, and particularly use of strains CV6 and V11 as a soil treatment, exhibited a reduction in disease incidence so that suppressed disease by 85.71 and 69.39% respectively. Pseudomonas flourescens CV6 significantly suppressed disease in comparison to Ridomil fungicide. The use of mixture bacterial strains in the soil inoculated by the fungus resulting in falling down the most of the plants which didn't show significant difference with infected control soils without bacteria.

• 한국임상수의학회지
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• 제24권2호
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• pp.125-129
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• 2007

Artemisia capillaris THUNB is a perennial herb that belongs to the family Compositae spp and the most common plant among the various herbal folk remedies used in treatment of abdominal pain, hepatitis, chronic liver disease, jaundice and coughing in Korea. This experiment was conducted to investigate the inhibitory effects of orally administrated Artemisia capillaris extracts on the pathogenic bacteria in 200 ICR mice. The experimental groups showed inhibitory effects on the bacteria in $1{\sim}3$ days after inoculation. After 21 days of inoculation, no viable bacterial cells appeared in the feces of both experimental groups while they did appear in the control group. The results of these studies indicate Artemisia capillaris extract exhibited excellent antimicrobial and inhibitory effects on the food poisoning pathogenic bacteria; S. enteritidis, E. coli O157:H7, L. monocytogenes and S. aureus.

• 한국유기농업학회지
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• 제19권spc호
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• pp.251-254
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• 2011

Botrytis cinerea infects stems and leaves of greenhouse tomatoes and can cause serious economic losses. This study was conducted to develop environment-friendly control method against tomato gray mold. Antagonistic microorganisms (bacteria) were screened for control activity against Botrytis cinerea, both in vitro and in vivo, using stem sections. One hundred bacterial strains were isolated from the rhizospheric soil of various plants including tomato. These strains were screened for growth inhibition of Botrytis cinerea on agar plate by the dual culture and thirty strains showing strongly inhibitory effect against the pathogen were selected first. Among thirty strains, JB 5-12, JB 22-2, JB 22-3, U 4-8 and U46-6 reduced significantly disease incidence, when applied simultaneously with the pathogen. These results suggested that five antagonistic bacteria strains selected have the potential to control tomato gray mold in organic farming.

• 한국미생물·생명공학회지
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• 제47권2호
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• pp.296-302
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• 2019

In this study, the effects of ammonium concentration ($117.5-1155.0mg-N{\cdot}l^{-1}$), nitrite concentration ($0-50.0mg-N{\cdot}l^{-1}$), and temperature ($15-35^{\circ}C$) on nitrification performance and its functional genes (amoA-arc, amoA-bac, hao) in an enriched consortium inoculated with humic acid were determined. Notably, the maximum nitrification rate value was observed at $315mg-N{\cdot}l^{-1}$ of ammonium, but the highest functional gene copy numbers were obtained at $630mg-N{\cdot}l^{-1}$ of ammonium. No inhibition of the nitrification rate and functional gene copy numbers was observed via the added nitrites. The optimum temperature for maximum nitrification performance was observed to be $30^{\circ}C$. The amoA-bac copy numbers were also greater than those of amoA-arc under all test conditions. Notably, amoA-arc copy numbers and nitrification efficiency showed a positive relationship in network analysis. These results indicate that ammonium-oxidizing archaea and bacteria play important roles in the nitrification process.

• Mycobiology
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• 제46권4호
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• pp.370-381
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• 2018

Bioactive natural compounds, isolated from fungal endophytes, play a promising role in the search for novel drugs. They are an inspiring source for researchers due to their enormous structural diversity and complexity. During the present study fungal endophytes were isolated from a well-known medicinal shrub, Berberis aristata DC. and were explored for their antagonistic and antioxidant potential. B. aristata, an important medicinal shrub with remarkable pharmacological properties, is native to Northern Himalayan region. A total of 131 endophytic fungal isolates belonging to eighteen species and nine genera were obtained from three hundred and thirty surface sterilized segments of different tissues of B. aristata. The isolated fungi were classified on the basis of morphological and molecular analysis. Diversity and species richness was found to be higher in leaf tissues as compared to root and stem. Antibacterial activity demonstrated that the crude ethyl acetate extract of 80% isolates exhibited significant results against one or more bacterial pathogens. Ethyl acetate extract of Alternaria macrospora was found to have potential antibacterial activity. Significant antioxidant activity was also found in crude ethyl acetate extracts of Alternaria alternata and Aspergillus flavus. Similarly, antagonistic activity of the fungal endophytes revealed that all antagonists possessed inhibition potential against more than one fungal pathogen. This study is an important step towards tapping endophytic fungal diversity for bioactive metabolites which could be a step forward towards development of novel therapeutic agents.