• Applied Biological Chemistry
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• v.42 no.2
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• pp.99-104
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• 1999

Soil actinomycetes of 703 strains were isolated from 25 sampling points in Cheju Island using 4 different media. Arginine glycerol salts agar containing soil extract was found to be the best medium for the isolation of soil actinomycetes. Soil samples from pasture land showed higher population and diversity of the actinomycetes than those from citrus field, forest, island, hill or valley. When the antibacterial activity of the 526 isolates was tested against three bacterial strains, Escherichia coli, Staphylococcus aureus and Pseudomonas solanacearum the frequency of the isolates with antibacterial activity varied much depending upon the media used for isolation and cultivation. BL106Ba, one of the 10 isolates that showed antibacterial activity against all the above 3 test strains, was chosen based upon the pH and heat stability of its antibacterial metabolites, and was identified as Streptomyces sp. based upon its cultural, morphological and physiological characteristics. The partially purified white crystalline substance obtained from the culture supematant of BL1063a through cation exchange chromatography(AG MP-50) and three times consecutive gel filtration(Sephadex G-10) showed high antimicrobial activity against gram positive and negative bacteria, but low activity against yeasts. The partially purified substance was found to contain at least four different compounds with antibacterial activity by both thin layer chromatography and high performance liquid chromatography.

• Korean Journal of Microbiology
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• v.38 no.4
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• pp.247-253
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• 2002

The cellular responses of TNT-degrading bacterium, Stenotrophomonas sp. OK-5 to explosive 2,4,6-trini-trotoluene (TNT) as an environmental contaminant were examined. Survival of the strain OK-5 with time in the presence of different concentrations of TNT under sublethal conditions was monitored, and viable counts paralleled the production of the stress shock proteins in this bacterium. Total cellular fatty acids analysis showed that strain OK-5 produced or disappeared several different kinds of lipids when grown on TNT media than when grown on TSA. Under scanning electron microscope, the cells treated with 0.5 mM TNT for 12 hrs showed irregular rod shapes with wrinkled surfaces. Analyses of SDS-PAGE and Western blot using anti-DnaK and anti-GroEL revealed that several stress shock proteins including 70 kDa DnaK and 60 kDa GroEL in strain OK-5 were newly synthesized at different TNT concentrations in exponentially growing cultures. 2-D PAGE of soluble protein fractions from the culture of OK-5 exposed to TNT demonstrated that approximately 300 spots were observed on the silver stained gel ranging from pH 3 to pH 10. Among them, 10 spots significantly induced and expressed in response to TNT were selected and analyzed. As the result of internal amino acid sequencing with ESI-Q TOF, two proteins, spot #1 and spot #10 were assigned the DnaK protein XF2340 of Xylella fastidiosa and stress-induced protein of Mesorhizobium loti, respectively.

• Microbiology and Biotechnology Letters
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• v.31 no.1
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• pp.75-82
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• 2003

The cellular responses of RDX-degrading bacterium, Pseudomonas sp. HK-6 to explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) were examined. Strain HK-6 grown at different RDX concentrations was found to demonstrate the survival rate in proportional to the rate of the stress shock proteins produced in this bacterium. Analysis of total cellular fatty acid acids showed that lipids 10:0 iso and 14:1 $\omega$5c/$\omega$5t increased approx three times in strain HK-6 grown on RDX media than TSA media. SDS-PAGE and Western blot using anti-DnaK and GroEL revealed that several stress shock proteins including 70 kDa DnaK and 60 kDa CroEL were newly synthesized in strain HK-6 exposed to different RDX concentrations in exponentially growing cultures. 2-D PAGE of soluble protein fractions from the culture of HK-6 exposed to RDX demonstrated that approximately 300 spots were observed on the silver stained gel ranging from pH 3 to pH 10. As a result, 10 spots were significantly induced and expressed in response to RDX. Scanning electron microscopy fur the cells treated with 0.135 mM RDX for 12 hrs showed the presence of perforations and irregular rod shapes with wrinkled surfaces.

• Korean Journal of Veterinary Research
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• v.14 no.2
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• pp.191-200
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• 1974

Hemoglobin, albumin and transferrin phenetypes observed in a population of 255 dogs of various breeds by agar gel electrophoresis for hemoglobin and albumin, and by starch gel electrophoresis, for transferrin. The results obtained were as follows: 1. The hemoglobin phenotypes were classified as HbAA, HbAB and HbBB and the frequencies of appearence were 91.77, 6.27 and 1.96%, respectively. Gene frequency studies of $Hb^A$ and $Hb^B$ showed the $Hb^A$ gene to have a frequency of 94.9% and $Hb^B$ gene to have a frequency of 5.1. The frequency of hemoglobin phenotypes of the Korean Jindo dog (ylelow) was HbAA 76.19%, HbAB 17.46% and HbBB 6.35% and HbBB was recognized only in the Korean Jindo dogs. 2. The albumin phenotypes were calssified as AlbAA, AlbAB and AlbBB and the frequencies of appearence were 28.71, 43.57 and 27.72% respectively. Gene frequency stduies of $Alb^A$ and $Alb^B$ showed the $Alb^A$ gene to hate a frequency of 50.50% and $Alb^B$ gene to have a frequency of 49.50. The frequency of albumin phenotypes of the Korean Jindo dog was 26.32% for AlbAA, 34.21% for AlbAB and 39.47% for AlbBB. The frequency of albumin phenotypes of the Korean Jindo dog was slightly different from others and gene frequency of $Alb^B$ was 56.58. 3. Transferrin studies resulted in findings of 10 different phenotypes and frequencies of transferrin phenotype were 30.08% for $TfA_1A_1$, 8.02 for $TfA_2A_2$, 2.11 for TfBB, 4.64 for $TfC_1C_1$, 1.69 for $TfA_1B$, 41.35 for $TfA_1C_1$, 5.49 for $TfA_2C_1$, 0.84 for $TfA_2C_2$ and 3.79 for $TfBC_1$. Gene frequency studies of $Tf^A$, $Tf^B$ and $Tf^C$ showed the gene to have a frequency of 63.08% for $Tf^A$, 4.85 for $Tf^B$ and 32.07 for $Tf^C$ 4. Transferrin studies revealed two different band patterns on starch gels with a strong and weaker stained one. The $TfC_2C_2$ and $TfA_2A_2$ which were found in the Korean Jindo dog only showed a weaker stained band and the gene frequency of $TfA_1A_1$ was highly recognized in this dog.

• Korean Journal Plant Pathology
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• v.1 no.1
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• pp.33-37
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• 1985

A yellow stripe and bud benting disease of soybean was commonly observed on the field at Suweon area. The causal agent was identified as alfalfa mosaic virus (AMV) by indicator plant reactions, physical properties, serological test and electron microscopy. AMV produced vein clearing, top necrosis, top bent and mottling on the parts of soybean plants. Local lesions were produced on the inoculated leaves of Vigna sesquipedialis, Vicia faba and Tetragonia expansa, while Chenopodium am, anticolor, C. quinoa, Pisum satvium, Petunia hybrida and Nicotiana tabacum 'Bright yellow' were systemically infected. The thermal inactivation point was $60^{\circ}C$, dilution end point was $10^{-3}$, and longevity in vitro was 2 days at room temperature. AMV from soybean was reacted with AMV - antiserum in agar gel diffusion test. Electron microscopy of AMV from soybean exhibited bacilliform particles of 60nm in length.

• Applied Biological Chemistry
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• v.33 no.4
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• pp.343-348
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• 1990

E. coli LE392, transformed with CDDP-treated pBR322 DNA, was plated on ampicillin containing media. The number of colonies formed on ampicillin containing agar plate was reduced to undetectable level after treat the DNA with 13.3 ${\mu}M$ CDDP. The CDDP-treated pBR322 DNA was susceptible to sing1e strand DNA specific S1 nuclease and it's migration Pattern in agarose gel electrophoresis was changed. These results suggest that CDDP adduction to pBR322 DNA resulted in denaturation of the double helix and changes in it's conformation which ultimately leads In the inactivation of the ampicillin resistant sere.

• Korean journal of applied entomology
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• v.22 no.3 s.56
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• pp.198-202
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• 1983

A mosaic disease of gladiolus has been commonly observed with an infection rate of $43.3\%$ in the field. Bean Yellow Mosaic Virus(BYMV) produced veinal spreading lesions on Cheonopodium amaranticolor, veinal necrosis and severe leaf distortion on Phaseolus vulgaris 'Scotia' and mosaic on Vi cia faba. Cucumber Mosaic Virus(CMV) produced local lesions on C. amaranticolor, mosaic symptoms on Nicotiana glutinosa and Cucumis sativus. BYMV and CMV were transmitted by the green peach aphid. Purified BYMV and CMV had a typical maximum absorption at 260nm. In agar gel diffusion test, BYMV and CMV gave positive reaction with their homologous antiserum. The size of BYMV was 750nm in length, and CMV was 30nm in diameter.

• Korean Journal of Veterinary Research
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• v.34 no.3
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• pp.529-536
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• 1994

To establish more specific and simple diagnostic methods for detection of the antibodies and antigens of Aujeszky's disease virus(ADV), we designed indirect dot-immunoassay(IDI) and double sandwich dotimmunoassay(DSDI) using the solid phases of nitrocellolose paper and polystyrene plate. The diagnostic efficacy of these methods was investigated. As the sensitivity of IDI was tested by various virus concentration, the specimens with the virus titer above $10^{4.0}TCID_{50}/0.2ml$ showed positive reaction, but that below $10^{1.0}TCID_{50}/ml$ revealed negative. Tonsil emulsion at the virus titer of $10^{4.5}TCID_{50}/0.2ml$ showed the highest sensitivity as diluted by 1/100. In detection of ADV antigens from the various tissues of the rats and pigs infected with ADV, IDI using monoclonal antibody showed the higher specificity as compared with IDI using polyclonal antibody and virus isolation method. The efficacy of the DSDI for detection of ADV antibody was compared with other tests. The sensitivity of DSDI was higher than virus neutralization(VN) and agar gel immunodiffusion test(AGID). Meanwhile, specificity of DSDI was lower than AGID, but similar to IDEA. In comparison with VN test, DSDI showed 96.9% agreement to VN test that is the highest of three tests. In general, application of polyclonal antibody in both tests caused the higher sensitivity but the lower specificty.

• Journal of Microbiology and Biotechnology
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• v.26 no.9
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• pp.1650-1656
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• 2016

The SCO0284 gene of Streptomyces coelicolor A3(2) is predicted to encode an α-galactosidase (680 amino acids) belonging to glycoside hydrolase family 27. In this study, the SCO0284 coding region was cloned and overexpressed in Streptomyces lividans TK24. The mature form of SCO0284 (641 amino acids, 68 kDa) was purified from culture broth by gel filtration chromatography, with 83.3-fold purification and a yield of 11.2%. Purified SCO0284 showed strong activity against p-nitrophenyl-α-D-galactopyranoside, melibiose, raffinose, and stachyose, and no activity toward lactose, agar (galactan), and neoagarooligosaccharides, indicating that it is an α-galactosidase. Optimal enzyme activity was observed at 40℃ and pH 7.0. The addition of metal ions or EDTA did not affect the enzyme activity, indicating that no metal cofactor is required. The kinetic parameters V_max and K_m for p-nitrophenyl-α-D-galactopyranoside were 1.6 mg/ml (0.0053 M) and 71.4 U/mg, respectively. Thin-layer chromatography and mass spectrometry analysis of the hydrolyzed products of melibiose, raffinose, and stachyose showed perfect matches with the masses of the sodium adducts of the hydrolyzed products, galactose (M+Na, 203), melibiose (M+Na, 365), and raffinose (M+Na, 527), respectively, indicating that it specifically cleaves the α-1,6-glycosidic bond of the substrate, releasing the terminal D-galactose.

• Microbiology and Biotechnology Letters
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• v.26 no.5
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• pp.450-455
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• 1998

Aspergillus oryzae M-2-3 strain (argB$\^$-/) was transformed with pTAalp plasmid which was constructed for expression of the alkaline pretense gene, alpA, and 16 transformants were selected on arginine minus medium. When these transformants were tested for productivity of alkaline proteases using agar plate containing skim milk, the halo was observed around each colony of transformants, but not observed around the host strain in this condition. Southern analysis showed that the pTAalp plasmid having alpA gene was integrated into the chromosome of the host strain. The highest level of alkaline protease production was obtained in the culture filtrate of the transformant No. 14, which was estimated to 80-90% of total secreted proteins, and the enzyme activity was 64-450 times higher than those of host strain and industrial strain. Total nitrogen content and the digestion rate in soybean Koji extracts were also increased to 1.5 times in Aspergillus oryzae transformant No. 14.