• Korean Journal of Microbiology
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• v.25 no.2
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• pp.122-128
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• 1987

Several bacterial isolates capable of degrading 4-chlorobiphenyl or 2,4,5-trichlorophenoxyacetic acid were isolated from industrial wastes by the agar plate method and studied for their biodegradabilities of the hydrocarbons and some biochemical characteristics. The isolates DJ-12, DJ-26 and TP-1 were identified as Pseudomonas spp. and they could not degrade 2,4-dichlorophenoxyacetic acid. The absorption spectra for 4-chlorobiphenyl and 2,4,5-trichlorophenoxyacetic acid showed the peaks at 253 and 292 nm, respectively. Biodegradability of the isolates was determined by decrease of the absorbance for the test hydrocarbons with a UV-scanning spectrophotometer. The plasmids of the isolates were studied to examine whether or not the hydrocarbon-degrading genes exist in the plasmids. Antibiotics resistance was also examined to search out a proper marker for the isolates in further experiments, such as curing test and genetic recombination.

• Journal of Environmental Science International
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• v.16 no.12
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• pp.1337-1343
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• 2007

The aim of this study was to isolate chicken feather-degrading bacteria with high keratinolytic activity and to investigate cultural conditions affecting keratinolytic enzyme production by a selected isolate. A chicken feather-degrading bacterial strain CH3 was isolated from poultry wastes. Isolate CH3 degraded whole chicken feather completely within 3 days. On the basis of phenotypical and 16S rDNA studies, isolate CH3 was identified as Bacillus thuringiensis CH3. This strain is the first B. thuringiensis described as a feather degrader. The bacterium grew with an optimum at pH 8.0 and $37^{\circ}C$, where maximum keratinolytic activity was also observed. The composition of optimal medium for keratinolytic enzyme production was feather 0.1%, sucrose 0.7%, casein 0.3%, $K_2HPO_4$ 0.03%, $KH_2PO_4$ 0.04%, $MgCl_2$ 0.01% and NaCl 0.05%, respectively. The keratinolytic enzyme had a pH and temperature optima 9.0 and $45^{\circ}C$, respectively. The keratinolytic activity was inhibited ethylenediaminetetraacetic acid, phenylmethylsulfonyl fluoride, and metal ions like $Hg^{2+},\;Cu^{2+}\;and\;Zn^{2+}$. The enzyme activated by $Fe^{2+}$, dithiothreitol and 2-mercaptoethanol.

• Journal of Life Science
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• v.19 no.3
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• pp.397-402
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• 2009

To isolate bacteria secreting protease, which can dissolve fibrin efficiently, we prepared chunggukjang using rice straw and isolated, preliminarily, approximately 100 bacterial stains. Their capabilities to dissolve milk protein as well as fibrin included in media were then examined and finally, five strains named J1 - J5 were selected. Among them, J-4, which is close to bacillus subtilis, showed highest activity for fibrin dissolution. Proteases secreted from the J-4 strain were partially purified from culture supernatant using DEAE-sepharose column chromatography and identified with SDS-polyacrylamide gel electrophoresis. Three proteins were subjected to analysis with MALDI-TOF and PMF (Peptide Mass Fingerprinting). 41.9 kDa protein was identified as a neutral protease. On the other hand, 45 kDa protein turned out to be bacillopeptidase F, with a molecular mass of 91.7 kDa, indicating that partially purified peptide is a degradation product.

• Food Science and Biotechnology
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• v.15 no.6
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• pp.967-974
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• 2006

Cyclomaltodextrinases (CDases), maitogenic amylases, and neopullulanases share highly conserved primary structures and similar characteristics, and are thus classified into the same family. BLAST search has showed that a variety of bacterial strains harbor putative CDase family genes with several well-conserved motif amino acid sequences. In this study, four degenerate polymerase chain reaction (PCR) primer sets were designed for the detection of CDase genes, on the basis of their highly conserved amino acid blocks (WYQIFP, DGWRLD, LGSHDT, and KCMVW). The PCR detection conditions were optimized and the detection specificity of each for the primer sets was tested against the genomic DNAs isolated from 23 different Bacillus-associated species. Consequently, all tested primer sets evidenced successful amplification of specific PCR products in length, which share 55-98% amino acid sequence identity with known and putative CDases. The primers developed herein, therefore, can be applied for the easy and efficient detection and isolation of CDase family genes for the modification of functional food carbohydrates.

• Food Science and Biotechnology
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• v.15 no.2
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• pp.214-219
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• 2006

A bacterial strain, initially identified as B1-3, was isolated from cheonggukjang, a traditional Korean dish made from fermented soybeans. Using the Biolog system and 16S rRNA sequence analysis, we identified B1-3 as Bacillus mojavensis. We manufactured a quickly fermented soybean (QFS) food product using the B. mojavensis, and guided by their 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging ability. We isolated substances with antioxidative activity from it. Using mass spectrometry (MS) and nuclear magnetic resonance (NMR) techniques, we isolated 4 compounds from the ethyl acetate (EtOAc)-soluble neutral fraction of methyl alcohol (MeOH) extracts of the QFS food product (genistein, daidzein, 3R,4R-3-methyl-3,4-dihydroxy-2-pentanone, and 3S,4R-3-methyl-3,4-dihydroxy-2-pentanone) and 3 compounds from its acidic fraction (4-hydroxyphenylacetic acid, genistin, and daidzein). Two compounds from the neutral fraction (3R,4R-3-methyl-3,4-dihydroxy-2-pentanone and 3S,4R-3-methyl-3,4-dihydroxy-2-pentanone) were not detected in nonfermented soybeans (NFS) or in the filtrate of the LB broth used to culture B. mojavensis. However, they were detected in the filtrate of the same broth when it contained 2% glucose. These results suggest that these 2 compounds were derived from glucose (or other saccharides) in the soybean during fermentation. One compound that was found in the acidic fraction (4-hydroxyphenylacetic acid) was readily detected in NFS, but not in the culture broth. This suggests that 4-hydroxyphenylacetic acid was derived from NFS. We concluded that the antioxidative activity of cheonggukjang is a result of the interactions between soybean components and the microorganisms used in the fermentation of cheonggukjang.

• Archives of Pharmacal Research
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• v.24 no.1
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• pp.44-50
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• 2001

To search for cytotoxic components from Allium victoriallis , MTT assays on each extract and an isolated component, gitogenin 3-O-lycotetroside, were performed against cancer cell lines. Cytotoxicities of most extract were shown to be comparatively weak, though $IC_50$ values of $CHCl_3$fraction was found to be <31.3-368.4 $\mu\textrm{g}/ml$. From the incubated methanol extract at $36^{\circ}C, eleven kinds of organosulfuric flavours were predictable by CG-MS performance. The most abundant peak was revealed to be 2-vinyl-4H-1,3-dithiin(1) by its mass spectrum. Further, this extract showed significant cytotoxicities toward cancer cell lies. Silica gel column chromatography of the n-butanol fraction led to the isolation of gitogenin 3-O-lycotetroside (3) along with astragalin (4) and kaempferol 3, 4'-di-O-$\beta$-D-glycoside (5). This steroidal saponin exhibited significant cytotoxic activities ($IC_50$, 6.51-36.5 $\mu\textrm{g}/ml$) over several cancer cell lines. When compound 3 was incubated for 24 h with human intestinal bacteria, a major metabolite was produced and then isolated by silica gel column chromatography. By examining parent and prominent ion peak in FAB-MS spectrum of the metabolite, the structure was speculated not to be any of prosapogenins of 3, suggesting that spiroketal ring were labile to the bacterial reaction. These suggest that disulfides produced secondarily are the antitumor principles.

• Journal of Korea Soil Environment Society
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• v.1 no.1
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• pp.39-46
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• 1996

For the purpose of development of bioremediation technology for soil contaminated by chlorinated phenols, this study was focused on the isolation and characterization of bacteria capable of degrading chlorinated phenols, the establishment of analytical methods for chlorinated phenols, and the investigation of the contaminated sites. One site near the Incheon Industrial Complex was identified as a pentachlorophenol (PCP)-contaminated spot. The soil brought from the PCP-contaminated site contained 10-100$mu\textrm{g}$/g wet soil of PCP. Many bacterial strains capable of growing on a minimal medium containing PCP were isolated from 15 soil samples collected throughout the land, and among them, 10 active isolates were finally selected for the further studies on the biodegradability and for the use in in situ bioremediation of contaminated soil. These isolates showed species-specific pattern in PCP-decrease and cell growth in a minimal medium containing 500-1,000mg/ιPCP. Strain Bul degraded 90% of PCP at 216 hrs after incubation. Expecially, strain Bu34 was capable of degrading 4,000mg/ι PCP and was identified as Pseudomonas putida Bu34. It is seemed that the isolated active bacteria could be effectively used for the bioremediation of PCP-contaminated sites.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.3
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• pp.373-382
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• 1994

A bacterial strain No. 40, which produced extracellular endoglucanase, was isolated from the rumen of Korean native goals and identified to be a genus of Actinomyces sp. The optimum conditions for endoglucanase production in PY-CMC medium were initial pH of 7.0 and 4 days of cultivation at $39^{\circ}C$. When localization of endoglucanase activity of Actinomyces sp. was determined, 68% of the enzyme activity was found in the extracellular fraction, 11% of the activity was detected in the periplasmic space and the remaining activity was in the intracellular and cell-bound fractions. The maximal endoglucanase activity was observed at pH 5.0 and it was most s table at pH 5.0. The optimum temperature of this enzyme activity was $55^{\circ}C$, but enzyme activity was gradually lost at temperature above $60^{\circ}C$. The crude enzyme was activated by addition of 10 mM cysteine and 10 mM DTT. But it was inhibited by addition of 10 mM $Cu^{{+}{+}}$ and $Fe^{{+}{+}}$. This crude enzyme could digest carboxymethylcellulose (CMC), and degrade xylan, avicel, pNPG, and pNPC to a less extent.

• Journal of Species Research
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• v.7 no.1
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• pp.36-49
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• 2018

During a study to discover indigenous prokaryotic species in Korea in 2016, a total of 42 actinobacterial isolates were recovered from various environmental samples collected from natural cave, squid, sewage, sea water, trees, droppings of birds, freshwater, eelgrass, mud flat, sediment and soil. On the basis of a tight phylogenetic clade with the closest species and high level of 16S rRNA gene sequence similarity, it was shown that each isolate was assigned to independent and previously described bacterial species which were assigned to the phylum Actinobacteria. The following 42 species have not been reported in Korea: eight species in two genera n the order Corynebacteriales, 26 species of 16 genera in the Micrococcales, one species of one genus in the Micromonosporales, one species of one genus in the Propionibacteriales, four species of two genera in the Streptomycetales and two species of two genera in the Streptosporangiale. Cell morphology, Gram staining reaction, colony colors and features, the media and conditions of incubation, physiological and biochemical characteristics, origins of isolation and strain IDs of 42 unrecorded actinobacterial species are presented in the species description.

• Korean Journal of Microbiology
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• v.50 no.1
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• pp.67-72
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• 2014

Minimal broth containing nicotine as a sole carbon source (MB/N) was used to isolate novel nicotine-degrading bacterial strains from tobacco plants and field soils. Comparative analysis of 16S rRNA gene sequence, phenotypic test and morphological tests showed that the position of these isolates were in the genus Arthrobacter of the family Micrococcaceae. The highest 16S rRNA gene sequence similarity of the isolate NU11 and NU15 to type strains in the genus Arthrobacter were Arthrobacter equi (98.2%) which was presumably a novel strain and Arthrobacter nicotinovorans (99.8%), respectively. Both strain NU11 and NU15 showed rod shaped, Gram-positive characteristics and catalase activity, but did not show oxidase activity. The novel strain NU11 was found to degrade efficiently nicotine in MB/N medium by the analysis of UV absorption spectra and could be used as an organism in bioremediation technique.