• 한국미생물·생명공학회지
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• 제17권3호
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• pp.252-256
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• 1989

해수환경에서 Bunker-C유를 가장 강력히 유화분산시키는 Acilromobacter sp. M-1220 균주를 대상으로 하여 생물유화제물질의 생성 및 그 성질을 조사하여 본 결과 유화제물질은 hexadecane oil 배지를 사용하여 18$^{\circ}C$에서 대수증식기 중기때에 가장 많이 생성되었다. 그리고 이는 양이온성의 peptidolipid 물질인 것으로 여겨지며 원유와 몇 종의 식용유에도 강한 유화안정능력을 보였다.

• 한국식품영양학회지
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• 제12권6호
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• pp.559-563
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• 1999

Essential oil of Artemisia lavandulaefolia the chrysanthemum family plant used in the chinese medicine was extracted and antibacterial and antifungal activity with many kinds of the pathogenic bacterium and fungi was experimented by it. Ataphylococcus epidermidis and Streptococcus aureus gram positive bacterium at the concentration of 200ppm and Streptococcus mutans at the concentration of 1,000ppm showed the growth injibition effect of the cell. These showed statistically significant difference(p<0.05) Zymomonas mobilis Entrecoccus faecalis gram negative bacterium at the concentration of 200ppm and Pseudomonas putida at the concentration of 400ppm showedd the growth inhibition effect of the cell)p<0.05) V. Parahaemolyticus at the concentration of 800ppm and Pseudomonas aeruginosa at the concentration of 1,000ppm showed the growth inhibition effect of the cell(p<0.05) Candida albicans and Cryptococcus neoformans yeast-type fungi showed the gorwth inhibition effect of the cell at the concentration of 200ppm(p<0.05) Altenaria mali Aspergillus nidulans and Fusarium oxysporum filamentous fungi took the growth inhibition effect of the cell at the concentration of 600ppm, 400ppm, and 100ppm. respectively.

• 한국식품영양학회지
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• 제1권2호
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• pp.95-101
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• 1988

In order to produce lactic acid and calcium lactate very useful for foods and medical supplies, lactic acid fermentation was studied by Lactobacillus sporogenes, a spore forming lactic acid bacterium. When this bacterium was cultured aerobically in the spore forming medium, the spore forming rate was 96.0% as total cell number 20$\times$108/ml, spore number 19.2$\times$108/ml. One minute agitating every 1 hour in the flask culture, or agitation of 100rpm in the fermenter was most efficient to continue to ferment at 45$^{\circ}C$ for 4days in the fermentation medium containing 10% glucose as carbohydrate and CaCO3 as a neutralizing agent. This homofermentative lactic acid bacterium showed fermentation yield of 99.3% and more than 98.2% of the yield was L(+)-lactic acid.

• Journal of Applied Biological Chemistry
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• 제43권4호
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• pp.264-268
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• 2000

High activity of acidic ethylacetate extract from the culture supernatant of ginseng growth-promoting bacterium Pseudomonas fluorescens KGPP 207 and its fractions were demonstrated through wheat coleoptile bioassay. The following auxins and auxin-like compounds were identified in these fractions by combined gas chromatography-mass spectrometry: indole-3-acetic acid, indole-3-acetic acid methyl and ethyl ester, indole-3-butyric acid, indole-3-lactic acid and its methyl ester, indole-3-propionic acid, indole-3-pyruvic acid, p-hydroxyphenyl acetic acid, p-hydroxyphenyl acetic acid methyl and ethyl ester, phenyl acetic acid and its methyl ester. The bacterium KGPP 207 belongs to the strain of P. fluorescens which produces plant growth regulators and its beneficial effect on the ginseng growth may be due to the formation of the identified compounds.

• Journal of Microbiology and Biotechnology
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• 제2권1호
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• pp.7-13
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• 1992

A moderately thermophilic, alkalophlic and powerful crystalline cellulose-digesting bacterium, Bacillus K-12, was isolated from filter paper wastes and found to be similar to Bacillus circulans or Bacillus pumilis, except for its ability to grow at a moderately high pH and temperature. The isolate grew at a pH ranging from 6 to 10 and at a temperature ranging from 35 to $65^{\circ}C$ and produced a large amount of cellulase components containing avicelase, xylanase, CMCase, and FPase when grown in avicel medium for 5 to 7 days at $50^{\circ}C$. The crude enzyme preparation from the culture broth hydrolyzed xylan, raw starch, pullulan and ${\beta}-1,3$ glucan such as laminarin. Furthermore, the enzyme hydrolyzed crystalline cellulose to cellobiose and glucose and had a broad pH activity curve (pH 6~9). The enzyme was stable up to $70^{\circ}C$.

• 약학회지
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• 제36권4호
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• pp.315-320
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• 1992

The amino acid threonine was produced from glycine and ethanol in a reaction mixture using resting cells of a newly isolated gram-negative methylotrophic bacterium, capable of growth on methanol. The isolate could utilize $C_1$ compounds and a variety of multicarbon substrates as sole carbon and energy source. To obtain cells of isolate with high threonine producing activity, we investigated optimum cultural conditions. Optimal growth was at the initial concentration of 0.5%(v/v) methanol, at $30^{\circ}C$ and pH 7.0. The growth was not affected by antibiotics inhibiting cell wall synthesis, but was completely suppressed by those inhibiting protein synthesis. The optimum reaction conditions from threonine production by resting cells of this strain were found.

• 한국미생물·생명공학회지
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• 제50권1호
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• pp.122-125
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• 2022

The cellulose-fed microbial fuel cell (MFC) is a biotechnological process that directly converts lignocellulosic materials to electricity without combustion. In this study, the cellulose-fed, MFC-integrated thermophilic bacterium, Bacillus sp. WK21, with endoglucanase and exoglucanase activities of 1.25 ± 0.08 U/ml and 0.95 ± 0.02 U/ml, respectively, was used to generate electricity at high temperatures. Maximal current densities of 485, 420, and 472 mA/m² were achieved when carboxymethyl cellulose, avicel cellulose, and cellulose powder, respectively, were used as substrates. Their respective maximal power was 94.09, 70.56, and 89.30 mW/m³. This study demonstrates the value of the novel use of a cellulase-producing thermophilic bacterium as a biocatalyst for electricity generation in a cellulose-fed MFC.

• Journal of Applied Biological Chemistry
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• 제65권4호
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• pp.447-451
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• 2022

Phytoestrogenic S-equol production in human gut exclusively depends on the biotransformation of daidzein to dihydrodaidzein (DHD). With a growing demand for the DHD enriched biomaterials, the commercial soybean hypocotyl extract (SHE) was chosen as a substrate for the microbial DHD production by human gut bacterium MRG-1, anaerobic DHD producer. To optimize the production of DHD, anaerobic fermentation conditions, including sterilization time, growth stage of inoculum, and growth media, were investigated. Maximum DHD production (1.2 g/L) was achieved after 48 h incubation when 1% (w/v) of SHE in the 20-min-sterilized Gifu Anaeboic Medium media was inoculated with OD₆₀₀ 0.3-0.4 of MRG-1. This is the first report that crude soy biomaterial, instead of pure compounds, such as daidzin and daidzein, is utilized for the production of the DHD enriched biomaterial.

• 한국균학회지
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• 제41권4호
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• pp.248-254
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• 2013

Pseudomonas tolaasii에 의해 발생하는 세균갈색무늬병은 버섯재배에서 문제가 되는 대표적인 병해이다. 본 연구에서는 세균갈색무늬병의 생물학적 방제법에 이용할 수 있는 독소저해균의 항균활성과 선발된 독소저해균에 대해 폿트수준의 생물검정 실험을 실시하였다. 재배중인 느타리버섯 폐면배지와 양송이 퇴비에서 세균갈색무늬병원균이 분비하는 독소(tolaasin)를 가장 강하게 억제하는 미생물 HC1를 선발하였으며, 생리 생화학적 실험과 유전적 실험결과 HC1균주는 Pseudomonas sp.로 동정되었다. 생물검정을 위하여 독소분해균 Pseudomonas sp. HC1을 양송이, 팽이, 느타리에 처리한 결과 각각 69%, 68%, 55%의 방제효과를 보였다. 따라서 Pseudomonas sp. HC1이 버섯 세균갈색무늬병 방제를 위해 합성농약을 대체할 수 있는 친환경적인 방제방법이 될 수 있을 것으로 생각된다.

• Journal of Oral Medicine and Pain
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• 제34권4호
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• pp.353-362
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• 2009

본 연구는 편백 피톤치드에 의해 사멸되지 않는 구강 상주균을 분리하고, 이 분리된 세균이 구강 병인균에 대하여 어떠한 영향을 미치는지를 관찰함으로써 편백 피톤치드에 구강 내 세균에 대한 지속적인 이차적 효과를 구명한 실험적 연구이다. 이에 건강한 사람의 타액에 1% 피톤치드를 첨가하여 최종적으로 생존해 있는 200개의 구강 상주균을 확인하여 이를 분석한 후 이들이 치주질환과 입냄새의 중요한 원인균인 F. nucleatum에 대한 억제효과를 관찰하여 다음과 같은 결론을 얻었다. 1. 선택된 200개의 잔존 세균 중, 70개(35.0%)가 F. nucleatum을 억제하였다. 2. F. nucleatum을 억제하는 70개의 잔존 세균 중, Streptococcus salivarius가 41.3%(45/109), Streptococcus sanguinis가 28%.(7/25), Streptococcus mitis가 20%(3/15), Streptococcus parasanguinis가 33.3%(3/9), Streptococcus alactolyticus가 100%(8/8), Streptococcus vestibularis가 28.6%(2/7), Streptococcus sp.가 50%(2/4)로 나타났다. 결론적으로 피톤치드 처리 후의 잔존 세균이 F. nucleatum을 억제함으로써 피톤치드가 구강 건강, 특히 치주질환을 예방하거나 치료하는데 큰 역할을 할 수 있을 것으로 생각하며, 구강 상주균을 건강하게 유지시킨 채로 병인균 만을 억제시킨다는 차원에서 향후 구강내 유익균의 배양가능성을 실용화 할 수 있다고 생각한다.