• 대한수의학회지
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• 제39권2호
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• pp.338-342
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• 1999

Twenty three strains of Escherichia (E) coli O157 : H7 isolated from Korea, Japan, USA were analyzed by pulsed-field gel electrophoresis (PFGE) of XbaI-digested chromosomal DNA and multiplex polymerase chain reaction. Various PFGE patterns of E. coli O157 : H7 were found on the same farm. Most of the E, coli O157 : H7 strains had shiga-like toxin (slt) II gene only (43.5%) or both slt I and slt II genes(30.4%). eaeA gene was highly conserved in the E. coli O157 : H7. There was no correlation between PFGE and slt gene patterns. The results indicate that various genotypes of E. coli O157 : H7 have spread throughout the country and genomic DNA patterns generated by PFGE are highly specific for different strains and have significant value in epidemiologic investigations of infectious disease outbreaks.

• 한국식품영양학회지
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• 제3권2호
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• pp.149-160
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• 1990

The soybean $\beta$-amylase ($\alpha$-1, 4-glucan maltohydrolase, EC 3.2.1.2) is composed of seven isozymes(I', I, II, III, IV, V and VI), and isozyme II and IV are the main components among these. The Purification of $\beta$-amylase isozymes from soybean whey were performed by ammonium sulfate fractionation, CM-Sephadex C-50 column chromatography, DEAE-Sephadex chromatography and Gel filtration. The resulted purity of $\beta$-amylase was throughly confirmed by electrophoresis, and then determined its isoelectric point and molecular weight. The results obtained were as follows, 1. Five active fractions of soybean p-amylase were derived on CM-Sephadex C-50 column chromatography. 2. Seven active bands of p-amylase isozymes were detected by isoelectric focusing gel electrophoresis, and their isoelectric points(I' to VI) were 5.07, 5.15, 5.25, 5.40, 5.55, 5.70 and 5.93, respectively. 3. Isozyme II and IV were main components of soybean $\beta$-amylase. 4. The molecular weights of both isozyme II and IV were determined to be 56,000 daltons by the result of SDS polyacrylamide gel electrophoresis. 5. Km values of main isozyme II & IV for amylopectin were determined to be 2.25 mg/ml, which suggest the same function of each isozyme.

• Journal of Microbiology and Biotechnology
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• 제21권9호
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• pp.885-892
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• 2011

The bacterial communities in the intestinal tracts of earthworm were investigated by culture-dependent and -independent approaches. In total, 72 and 55 pure cultures were isolated from the intestinal tracts of earthworms under aerobic and anaerobic conditions, respectively. Aerobic bacteria were classified as Aeromonas (40%), Bacillus (37%), Photobacterium (10%), Pseudomonas (7%), and Shewanella (6%). Anaerobic bacteria were classified as Aeromonas (52%), Bacillus (27%), Shewanella (12%), Paenibacillus (5%), Clostridium (2%), and Cellulosimicrobium (2%). The dominant microorganisms were Aeromonas and Bacillus species under both aerobic and anaerobic conditions. In all, 39 DNA fragments were identified by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis. Aeromonas sp. was the dominant microorganism in feeds, intestinal tracts, and casts of earthworms. The DGGE band intensity of Aeromonas from feeds, intestinal tracts, and casts of earthworms was 12.8%, 14.7%, and 15.1%, respectively. The other strains identified were Bacillus, Clostridium, Enterobacter, Photobacterium, Pseudomonas, Shewanella, Streptomyces, uncultured Chloroflexi bacterium, and uncultured bacterium. These results suggest that PCR-DGGE analysis was more efficient than the culturedependent approach for the investigation of bacterial diversity and the identification of unculturable microorganisms.

• BMB Reports
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• 제28권2호
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• pp.143-148
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• 1995

In E. coli, chromosomal DNA associated with proteins is condensed into an organized structure known as nucleoid. Using a nitrocellulose filter binding assay to identify proteins forming nucleoid, a 21 kDa protein was purified from E. coli. The molecular weight of the purified protein was 21 kDa on SDS-polyactylamide gel electrophoresis and 24 kDa on gel permeation chromatography. A molecular weight of 21 kDa on SDS-polyacrylamide gel electrophoresis is unique among known proteins which are believed to be involved in the formation of nucleoid in E. coli. The 21 kDa protein nonspecifically binds to both double-stranded and single-stranded DNA. Sedimentation in a sucrose gradient revealed that the protein induced significant condensation of both supercoiled plasmid DNA and linear bacteriophage $\lambda$ DNA On the basis of quantitative Western-blot analysis, approximately 40,000 molecules of the protein were estimated to exist in an E. coli. The biochemical properties and cellular abundance of the 21 kDa protein suggest that this protein participates in the formation of nucleoid in E. coli.

• 한국수산과학회지
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• 제36권4호
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• pp.346-351
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• 2003

Single-cell gel electrophoresis (comet assay) was used to detect DNA single strand break in blood cells from several marine fish species. Three fish species were collected from Georgia coastal area. Mummichog, Fundulus heteroclitus showed higher DNA damage than sea bass, Lateolabrax japonicus and trout, Oncorhynchus masou masou under the same experimental conditions. Mummichogs had more alkaline-labile sites on their DNA than other fish species. The comet assay with mummichog blood cells at pH 12.5 showed a dose-response curve with the increasing concentrations of hydrogen peroxide. While the isolated leucocytes showed no increase of DNA damage after in vitro exposure to 2-methyl-1,4-naphthoquinone (MNQ), erythrocytes showed dose-dependent DNA damage. These results indicate that the comet assay can be applied successfully as a bioassay using erythrocyte for environmental monitoring.

• Journal of Microbiology and Biotechnology
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• 제16권11호
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• pp.1814-1818
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• 2006

Vibrio cholerae O1 El Tor isolates (n=242), collected in Korea between 1991 and 2002, were classified by NotI-digested pulsed-field gel electrophoresis (PFGE). The major types were Al before 1998 and B after 1999, among both domestic and imported cases. The prevalent PFGE types among domestic cases were consistent with the prevalent types among imported cases in the same year. These results suggest a close relationship between the domestic and imported cases of cholera in Korea.

• 한국미생물·생명공학회지
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• 제27권6호
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• pp.471-476
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• 1999

Inulin fructotransferase(depolymerizing)(EC 2.4.1.93)(inulaseII) which converts inulin into di-D-fructofuranose-1,2':2,3'-dianhydride (DFAIII) was purified from Arthrobacter ureafaciens KCTC 3387 using column chromatography on DEAE-Toyopearl 650M and gel filtration of Sephadex G-200. The enzyme was purified 7-fold with a yield of 11% from a culture supernatant. The purified enzyme gave a single band on polyacrylamide gel electrophoresis, and the molecular weight of the enzyme was estimated to be 45,000 by SDS-polyacrylamide gel electrophoresis. The optimum pH and temperature for the enzyme reaction were pH6.5~7.0 and $55{\circ}C$, respectively. The enzyme was stable within a pH range of 5.0 to 10.6 and up to $60^{\circ}C$. The Km of this enzyme for DFAIII production was 11.9mM. The enzyme was inactivated by $Hg^{2+}$ and after exhaustive digestion of inulin by this enzyme, 1-kestose and nystose were produced in addition of DFAIII.

• 약학회지
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• 제36권3호
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• pp.241-249
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• 1992

The whole body extract of Lunella coronata coreensis agglutinated nonspecifically human and other animal erythrocytes. A new lectin was purified by the following procedures: 0.15 M NaCl extraction, salt fractionation, gel filtration, anionic and cationic ion exchange column chromatographies. Through these purification procedures, specific activity of LCC-I was increased from 276 to 9714.3 units/mg, And on polyacrylamide gel electrophoresis, LCC-I exhibited one major band. A molecular weight of LCC-I was assumed to be 20,000 by sodium dodesyl sulfate polyacrylamide gel electrophoresis. The purified lectin was relatively stable at various pH and heat. Among the tested sugars, lactose and lactulose inhibited lectin activity at a concentration of 6.25 mM, respectively.

• 한국미생물·생명공학회지
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• 제16권6호
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• pp.438-442
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• 1988

The enzyme produced by Rhizopus japonicus was able to convert selectively ginsenoside-Rb$_1$which is the most abundant ginseng saponin, into ginsenoside-Rd which was known to be superior to ginsenoside-Rb$_1$pharmaceutically. The convertible enzyme was purified homogeneous from wheat bran culture of Rhizopus japonicus by ammonium sulfate fractionation and column chromatography of TEAE-cellulose, DEAE-Sephadex A-50, Sephadex G-150, Sepharose 2B. Specific activity of the purified enzyme was increased to a bent 96 folds and yield was appeared to be 11% of culture extract. Evidence for homogenity was obtained from polyacrylamide and SDS-polyacrylamide gel electrophoresis. Molecular weight of the enzyme was estimated about 88, 000 daltons by Sephadex G-l50 gel filtration and SDS-polyacrylamide gel electrophoresis, and it did not consist of any subunit.

• 한국식품영양과학회지
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• 제20권4호
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• pp.388-394
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• 1991

Alkaline protease producing bacteria were isolated from soil and identified as Bacillus sp. CW-1121. It was found that the production of alkaline protease reached to maximum in 5 day of fermentation at 4$0^{\circ}C$. The enzyme was purified by ammonium sulfate precipitation, gel filtration on Sephadex G-150 and DEAE-cellulose ion-exchange chromatography. The homogeneity of the purified enzyme was verified by polyacrylamide gel electrophoresis. The enzyme was purified 5.72 fold and yield of the enzyme purification was 16.71%. When the purified enzyme was applied to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the molecular weight was estimated to be 55, 000.