• Korean Journal of Microbiology
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• v.47 no.1
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• pp.74-80
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• 2011

Bacteriocin-producing lactic acid bacterium having antagonistic activity against Bacillus cereus, was isolated from Kimchi. The selected strain was identified as Lactococcus lactis by the Bergey's manual and 16S rDNA analysis, and named as L. lactis ET45. The bacteriocin was stable in the pH range 3.0-11.0. The bacteriocin was active over a wide temperature range from $40^{\circ}C$ to $121^{\circ}C$. Optimal culture condition for producing bacteriocin was obtained by growing the cells on MRS medium at pH 7.5 and $30^{\circ}C$ for 18 h. Antibacterial activity of the bacteriocin was completely disappeared by proteinase K, and this means that bacteriocin is a proteinous substance. The molecular weight of bacteriocin was estimated to be about 4.5 kDa by tricine sodium dodecyl sulfate polyacryamide gel electrophoresis (TSDS-PAGE).

• Applied Microscopy
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• v.8 no.1
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• pp.9-15
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• 1978

Five strains of the Genus Rhizobium were isolated from the nodules of five leguminous plants respectively. They were identified according to Bergey's Manual together with the results of Vincent. The flagella of each strains were observed by electron microscope using negative staining with PTA and metal shadowing with chromium. Five host plants and identified Rhizobium strains were as. follows. Pisum sativum.....R. leguminosarum Phaseolus vulgaris.....R. phaseoli Trifolium repens.....R. trifolii Glycine max.....R. japonicum Lupinus grandiflorus.....R. lupini Electron micrographs showed that R. leguminosarum and R. phaseoli had 4 peritrichous flagella, where as R. trifolii had 5 peritrichous flagella. On the other hand, R. japonicum and R. lupini had 1 subpolar flagellum.

• Microbiology and Biotechnology Letters
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• v.17 no.2
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• pp.115-120
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• 1989

For the purpose of obtaining microorganisms which produced an extracellular pepsin inhibitor, screening test was carried out. One strain of Actinomycetes (GF 155-2) isolated from soil samples showed a high inhibitory activity against porcine pepsin. The morphological, physiological and cultural characteristics of the strain GE 155-2 on various culture media were studied according to ISP methods and Bergey's manual of determinative bacteriology (8th ed.). This Actinomycetes GE 155-2 was found to be similar to the genus Microtetraspora.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.10a
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• pp.319-323
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• 2005

Lactic acid bacteria are dominant microflora in many kinds of fermented foods. In this study, dominant microflora, especially lactic acid bacteria were isolated from salted sea food, and we determined physiological characteristics, and assayed specific property such as bacteriocin activity. The population of lactic acid bacteria as well as aerobic mesophilic counts was at the level of $10^7$ cfu /g. Total 17 strains of LAB were isolated from salted sea food sample. The phenotypic characteristics of these strains were determined followed by Bergey's Manual. And genotypic and bacteriocin activity were tested by Schillinger and $L{\ddot{u}}cke^{(7)}$.

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.88-88
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• 1995

Microorganism are centIal core to biosphere sm1ainablity and biogeochemical cycles on this earth. Most of food, medical and pabamceutical new materials through biotechnology are derived from many kinds of microorganisms. Microorganisms are important resources of biotechnology. Beside these, micorbial diversity is key to explore the frontiers of knowledge about the strategies and limits of life. Through the micorotganisms, we can monitor the environmental changes and conditions. Moreover, the microorganismsms play a role in conservation and restoration of higher plants and animals. And we can get a lot of ecological, evolutionary knowledges from microbial models. In spite of these importances, the microbial diversity is not properly evaluted because of their unculturablity. Only 0.001 - 3 % of total bacteria in natural habitats are cultumble and the rest are viable but uncultumble. Only 3,100 species are listed up in the Bergey's Manual. Considering the symbisis and estimated numbers of insect are more than 800,000, the symbiotic microorganisms are about 1,000,000 species. Recently, by using the genetic and molecular technics, the microbial diversity is now unveiled. In this symposium, the genetic, species and ecological diversity will be given. given.

• The Korean Journal of Mycology
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• v.30 no.1
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• pp.44-49
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• 2002

The study was conducted to isolate and identify insecticidal bacteria for biological control of larvae of mushroom fly, Lycoriella mali, which is one of serious pests to oyster mushrooms during its cultivation period. Among eight bacteria isolated from the soil in the oyster mushroom beds and the dead body of L. mali, two bacteria, Bti-D and Bti-U showed more toxicity with mortality rate than other six-bacteria isolates. The two bacteria showed more toxicity in three instar of the period of development of the mushroom fly than in other instar. Symptoms of the larvae of L. mali infected by the two bacteria developed as follows: at the early infection, the front middle gut changed color to light brown, the middle gut to brown, whole body to black brown, and eventually, the fly died. For the identification of these isolates, cultural and biochemical characteristics by Bergey's manual and Biolog system, cell morphology by TEM, endospore and endotoxin by phase-contrast microscope, and test using 33H antisera were examined. According to the results, these two isolates, Bti-D and Bti-U were identified as Bacillus thuringiensis subsp. israelensis respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.516-522
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• 1998

An Actinomycetes strain, MSA-1, containing antimicrobial component was isolated from the black sponge, Halichondzia okadai, and was identified to a genus level by morphological and chemotaxonornic methods. The gray colored spores were oval type with smooth surface and formed flexibilis spore chains. The cell wall of this strain was type I containing D-aminopimellic acid (D-DAP) and no specific sugar was detected. Phospholipid of the cell membrane was PII type including phophoethanolamine and the major fatty acids of total lipid were branched anteiso-15 : 0, iso-16 : 0, 16 : 0 and iso-17 ; 0. From these results and other characteristics described in the Bergey's Manual, this strain was identificated as a Streptomyces sp. Meanwhile, 10mg of pale yellow colored antimicreobial component was isolated by HPLC method from the cultured Streptomyces sp. (70g of cryophillized mycellis). By crystallographyc analysis, HIRESMS and NMR assignment, the antimicrobial component produced from the strain MSA-1 was elucidated as the staurosporine (indolo[2,3-a]carbazole alkaloid).

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.754-759
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• 2002

In order to develope a new pretense applicable to industries, a bacterium which produces a remarkable amount of extracellular pretense were isolated from soil. About 10 bacterial strains producing pretense were isolated from samples of soil, and strain PANH765 showed the highest activity of pretense production among them. The strain was identified as Bacillus subtilis according to the Bergey's Manual of Systematic Bacteriology based on its morphological, cultural and physiological characteristics. B. subtilis PANH765 showed the maximal production of pro-tease in the medium containing 2.0% glucose, 1.0% yeast extract, 0.2% ammonium nitrate, 0.02% ferrous sulfate and 0.02% dipotassium hydrogen phosphate. Under the optimal condition with temperature of 3$0^{\circ}C$, initial pH of 7.0 and shaking speed of 150 rpm, the pretense production reached a maximum level with 36 hr cultivation (6.34 U).

• Applied Biological Chemistry
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• v.48 no.1
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• pp.48-52
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• 2005

Six stains of plant growth promoting rhizobacteria were selected through germinating seed assay and root colonization assay. Among them, SKU-78 strain induced significant suppression of bacterial wilt disease in tomato and pepper plants. Seed treatment followed by soil drench application with this strain resulted in over 60% reduction of bacterial wilt disease compared with the control. It was suggested that SKU-78 strain activated the host defense systems in plants, based on lack of direct antibiosis against pathogen. According to Bergey's Manual of Systemic Bacteriology and 16S rDNA sequence data, SKU-78 stain was identified as Bacillus sp. SKU-78.

• Research in Plant Disease
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• v.10 no.1
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• pp.8-12
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• 2004

The diseased ginseng plants, their trunks fall down anil roots rot, were observed in ginseng cultivation field at Bongwha, Kyungbuk. Inoculation of the bacterium isolated from root rot lesion induced a range of symptoms on leaves, trunks and roots; The bacterium caused wilting with chlorosis and black discoloration on leaves, empty of inside trunks and rot on roots. The bacterium was identified as Serritia liquefaciens based on the morphologcal and physiological characteristics. This is the first report in Korea on roots rot of ginseng occurred by S. liquefaciens.