• Microbiology and Biotechnology Letters
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• v.29 no.1
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• pp.37-42
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• 2001

An antifungal substance was purified from culture broth of Pseudomonas flulorescens 2112 that showed a broad-spectrum antagonistic activity against various phytopathogenic fungi including capsici. The substance was identified as 2,4-diacetylphloro-glucinol basd on NMR analysis. The 2,4-diacetylphloroglcinol showed antibiotic activity in broad acidic range from pH 1.0 to pH 9.0. About 83% of initial activity was remained after incubation for 30min ar $60^{\circ}C$, however, the activity was dropped up to 50% after 30 min incubation in $80^{\circ}C$. When the nucleotides of P. capsici treated with 2,4-diacetylphloroglucinol were labeled with[$^{3}$ H]-Adenin, the newly synthesized and radioactive-labeled RNA was significantly reduced than those of untreated P. capsici. indicating that the 2,4-diacetylphloroglucinol inhibits RNA synthesis.

• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.138-148
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• 2006

Two bacteria were isolated from the continuously pesticide-used soil under plastic film house and upland condition. The degradation test of several pesticides by the selected bacteria, B59 and B71, were conducted. The degradation rates for 6 pesticides, procymidone, chlorothalonil, ethoprophos parathior, alachlor and pendimethalin, in medium by the isolates were 21.1% to 53.2% higher than non-inoculated medium. Under shaking culture condition, 90% to 95% of procymidone was degraded after 21 days treatment. Parathion was degraded in the range of 60% to 100% by B71 and B59, respectively. Otherwise 70% of alachlor was degraded by the two isolated bacteria during same period. The pH was not significantly affected for degradation of pesticides. The bacterial strains, B59 and B71 was identified as Acinetobacter sp. and as Pseudomonas sp. based on morphological, biochemical and physiological characteristics, and identity and similarity of automatic identification system, Biolog and MIDI.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.5
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• pp.534-538
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• 1992

This study was carried out to investigate the effect of potassium sorbate on the growth of yogurt starter and contaminant yeast. Yogurt starter was isolated using 9 company of market yogurt and 10 strains of contaminant yeast was isolated in swollen yogurt after incubated for 7 days at $25^{\circ}C.$ The growth of isolated starter was inhibited by 0.3% of potassium sorbate except starter-H. Most isolated yeast was inhibited by the 0.1% of potassium sorbate. The growth of yeast-9 was the most inhibited among isolated yeast. The growth of selected starter-H was similiar to that of control in MRS broth containing 0.3% of potassium sorbate. 0.3% of potassium sorbate did not affect the growth of selected starter-H incubated with selected yeast-9 in skimmilk at $37^{\circ}C$ for 48hr, whereas, the growth of yeast-9 did not occur during incubation. The viable cell change of starter-H in yogurt contaminated with selected yeast-9 was not observed at $4{\pm}1{\circ}C$ for 7 days and the contaminant inhibited in 0.3% potassium sorbate containing yogurt during storage at $25^{\circ}C.$

• Applied Biological Chemistry
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• v.50 no.1
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• pp.23-28
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• 2007

Auxin-producing antagonistic bacterium K11, which can inhibit Phytophtora capsici, was isolated from a local red-pepper field soil in Gyeong-buk. In order to check for additional PGPR(plant growth promoting rhizobacterium) functions of the strain K11, we confirmed siderophore and cellulase productions by CAS (chrome azurol S) blue agar and CMC plate with congo red, respectively. The strain K11 was identified as Bacillus licheniformis with 98% similarity on 16s rDNA comparison and Biolog analyses. B. licheniformis K11 promoted mung bean adventitious root induction and enhanced root growth of mung bean (160%), pea (150%), and Chinese cabbage (130%), Also, B. licheniformis K11 was able to effectively suppress (63%) P. capsici causing red-pepper blight in the pot in vivo test. Therefore, we could select a triple-functional PGPR which has auxin, siderophore, and cellulase producing ability for effective crops production in organic farming.

• Research in Plant Disease
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• v.12 no.2
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• pp.85-90
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• 2006

Bacillus subtilis BD0310 isolated from tea leaves was used for the development of a biofungicide against Pestalotiopsis longiseta causing gray blight of tea plants. The optimum growth conditions were investigated for the mass cultivation of the microbial agent. The optimum temperature and cultivation time were determined as $12{\sim}24$ hours at $30^{\circ}C$ and the optimum initial pH was pH 7.0 in nutrient broth. Among the tested carbon sources of fructose, galactose, glucose, glycerol, inositol, lactose, maltose, sorbitol and starch, maltose and inositol were found to highly increase antifungal activity of the microbial agent against P. longiseta. Yeast extract and tryptone apparently increased antifungal activity of the microbial agent among the tested nitrogen sources of casein, tryptone, malt extract, yeast extract and $(NH_4)_2SO_4$. The results will make a contribution to mass production of the antagonistic bacterium Bacillus subtilis BD0310 for development of a microbial agent controlling gray blight of tea plants.

• The Korean Journal of Pesticide Science
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• v.20 no.4
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• pp.380-387
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• 2016

This study was performed to select potentially available biological control agent from soil bacteria for prevention of ginseng damping off. More than five hundred strains were isolated from ginseng rhizosphere soil. By testing antifungal activity, we have selected three soil bacteria strains and their ability to produce antibiotics and lytic enzymes such as cellulase, protease and pectate lyase was examined. Also, the presence of genes for biosynthesis of lipopeptide such as fengycin, bacillomycin D, surfactin, iturin A, and zwittermicin A was investigated in selected strains. All three strains produced cellulase, protease, and xylanase. Moreover, these strains had gene for biosynthesis of bacillomycin D, surfactin, and iturin A. ES1 and ES3 strains were identified Bacillus methylotrophucus and ES2 was confirmed Bacillus amyloliquefaciens using phylogenetic analysis on the basis of 16S rRNA gene sequences. In field test, control value of ES1, ES2 and ES3 treatment was 32.4%, 46.8% and 36.7%, respectively. This results indicate that antagonistic microbes with high ability of antifungal and lytic enzyme activity can be used as a useful biological control agent to control ginseng damping off.

• The Microorganisms and Industry
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• v.16 no.2
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• pp.58-61
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• 1990

항생제 생산을 위한 생물공정은 크게 3단계로 나뉠 수 있다. 우주균주 선발, 현장균주 보존및 현장 종균 공급을 위한 일련의 종균배양 과정을 Upstream이라 할 수 있고, 종모실로 부터 공급받은 종균을 현장에서 증식시키는 현장 종균배양 공정과 본 발효조에서의 항생제 생합성공정을 Mid-Stream, 발효가 끝난 상태의 배양액으로부터 균체, 세포내 및 세포외 불필요한 물질을 제거하고 항생제만을 회수, 정제하는 Down Stream으로 나뉠 수 있다. 따라서 항생제 발효는 좁은 의미에서는 본 발효조에서의 항생제 생합성공정을 가르키지만 넓은 의미에서는 위 전체 공정을 가르키는 말이기도 하다. 따라서 본 소고에서는 항생제 생산을 위한 생물 공정상의 문제점을 3분야로 나누어 제시하고자 한다. 실제로 항생제 공장을 건립하여 항생제 발효를 실시해 왔으며 그것을 좀더 나은 수준으로 개선하고자 꾸준히 노력해 온 당사에서의 경우를 그 예로 보아 문제점을 제시하고자 한다.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.10a
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• pp.388-390
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• 2004

본 연구는 자돈 설사의 원인이 되는 대장균, 살모넬라 등 그람음성균을 억제할 수 있는 유산균의 이용을 위해 선발된 균주의 과산화수소 대사를 구명하기 위해 수행하였다. 대장균 억제유산균중 superoxide dismutase 활성이 우수한 균주가 관찰되었으며, 과산화수소 이외에 그람음성균 억제에 유효한 bacteriocin-like compounds의 존재 유무, 대사과정에서 과산화수소 생성과 관련된 다른 효소 활성, superoxide dismutase 유전자 클로닝에 관한 연구가 진행중이다.

• Korean Journal of Food Science and Technology
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• v.39 no.3
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• pp.315-322
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• 2007

This study was carried out to investigate the functional activities of microorganisms isolated from kochujang, such as fibrinolytic, immunostimulating, and cytotoxical activities, and to apply these microorganisms to kochujang products. Ninety-one microbial strains with proteolytic activity were selected from 294 strains isolated from traditional and commercial kochujang. Three strains (TPP 0014, TPP 6013, and TPP 6015) with high fibrinolytic activity were tested for their immunostimulating and cytotoxical activities. For the assessment of macrophage activation, cytokines such as tumor necrosis factor, $interleukin-1{\alpha}$ and nitrogen oxide were measured with the murine macrophage cell line RAW 264.7. In addition, the cytotoxical activities of the three strains were examined by MTT assay on the colon cancer cell line SNU-C4 and normal cell line CHO-K1. Using an API identifying kit, two of the microbial strains (TPP 0014 and TPP 6015) were identified as Bacillus stearothermophilus and the other strain (TPP 6013) was identified as B. amyloliquefacience.

• Food Science of Animal Resources
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• v.26 no.1
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• pp.106-112
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• 2006

Fifty four acid-resistant and bile-resistant isolates of lactic acid bacteria were initially isolated from the faces of Korea native cattle and Holstein using MRS agar and LAPT agar, and ten strains with superior activity against bile salt were finally selected LS1, LS15, and LL6 isolates showed survival of 66.5%, 82.6% and 80.7% against the simulated stomach liquid(pH 2.5), respectively. LL6 and LL7 isolates had the highest inhibitory activities against the pathogenic bacteria such as Salmonella typhimurium, Staphylococcus aureus, and Clostridium perfringens. By using API 50 CHL kit LS1, LS2 and LM1 isolates were identified as a L. fermentum. LL6 and LL7 isolates as a L. acidophilus, and LS3 isolate as a L. plantarum. The other four isolates belong to genus Lactobacillus. All the isolates tested were sensitive to some antibiotics such as ampicillin, amoxicillin and erythromycin, but resistant to colistin and ciprofloxacin. LB1, LL6 and LL7 isolates were resistant to gentamicin and neomycin. Especially, the LL6 isolate showed the highest resistance to both of the simulated stomach liquid and bile salt, in addition to the highest inhibitory activities against Sal. typhimurium, Staph. aureus and Cl. perfringens.