• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.11
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• pp.1401-1407
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• 2008

1-Deoxynojirimycin (DNJ) is a strong $\alpha$-glucosidase inhibitor which inhibits hyperglycemia in animals. To select the Bacillus strains highly producing DNJ, 4,000 strains were isolated from soil and grain samples. By the inhibitory activity against $\alpha$-glucosidase, nine Bacillus strains were selected and then identified by 16S rDNA sequencing. B. subtilis S10 was finally selected as the best strain for the production of DNJ. Various carbon sources and nitrogen sources in culture medium were evaluated for the highest production of DNJ. As the results, the optimized concentration of carbon source and nitrogen source was 1.0% galactose and 1.6% polypeptone and the concentration of DNJ produced was 0.75 g/L. The effect of culture supernatant of B. subtilis S10 on lowering blood glucose level was investigated in streptozotocin (STZ)-induced diabetic mice model. Mice were randomly assigned to control group (saline) and three test groups such as acarbose group, silkworm powder group and B. subtilis S10 group. After eight-week oral feeding, blood glucose levels of the B. subtilis S10 and silkworm powder groups were respectively $209.1{\pm}19.6\;mg/dL$ (59.1%) and $208.6{\pm}39.8\;mg/dL$ (59.0%) lower than $510{\pm}10\;mg/dL$ of the control group. These results indicated that the culture supernatant of B. subtilis S10 was able to reduce the blood glucose level in STZ-induced diabetic mice.

• Journal of Life Science
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• v.18 no.12
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• pp.1625-1630
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• 2008

A microorganism capable of producing high level of poly-3-hydoxybutyrate (PHB) from xylose was isolated from soil. The isolated strain J-65 was identified as Bacillus megaterium based on the morphological, biochemical and molecular biological characteristics. The optimum temperature and pH for the growth of B. megaterium J-65 were $37^{\circ}C$ and 8.0, respectively. The optimum medium composition for the cell growth was 2% xylose, 0.25% $(NH_4)_2SO_4$, 0.3% $Na_2HPO_4{\cdot}12H_2O$, and 0.1% $KH_2PO_4$. The optimum condition for PHB accumulation was same to the optimum condition for cell growth. Copolymer of ${\beta}$-hydroxybutyric and ${\beta}$-hydroxyvaleric acid was produced when propionic acid was added to shake flasks containing 20 g/l of xylose. Fermenter culture was carried out to produce the high concentration of PHB. In batch culture, cell mass was 9.82 g/l and PHB content was 35% of dry cell weight. PHB produced by B. megaterium J-65 was identified as homopolymer of 3-hydoxybutyric acid by GC and NMR.

• Weed & Turfgrass Science
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• v.4 no.3
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• pp.219-224
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• 2015

This study was conducted to evaluate the effect of herbicidin, new natural herbicidal substances, derived from soil actinomycetes Streptomyces scopuliridis. Several weed species were subjected to examine the germination inhibition and herbicidal activity at the concentration from 100 to 2,000 ppm. There was no selectivity in germination inhibition and herbicidal activity against crops. Germination of Echinochloa oryzoides, Digitaria ciliaris, Abutilon theophrasti and Amaranthus retroflexus was inhibited completely when 7.81 ppm of extract was treated in petri dish. Pre-emergence application of herbicidin in soil condition showed low inhibition against weeds. However, post application of herbicidin in green house resulted in the necrosis of weeds at the concentration of 2,000 ppm. A. retroflexus was sensitive to herbicidin at the low concentration of 62.5 ppm, whereas E. oryzoides was tolerant to lower concentration of herbicidin until it became withered at the concentration of 2,000 ppm. In conclusion, herbicidal substances derived from S. scopuliridis herbicidin, which is consisted with herbicidin A and B, have dominant effect on germination and growth inhibition. On the other hand, herbicidin was insufficient to control gramineous weeds. In future, it will be needed to develop the combination of herbicidin with other herbicide or compounds to control gramineous weeds as well.

• Korean Journal of Ecology and Environment
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• v.50 no.1
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• pp.137-147
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• 2017

The identity of toxin producers remains only hypothesis unless there were identified by strain isolation and analytical confirmation of both the cyanotoxin production and the genetic identity of the monoculture. The purposes of this study were to identify a morphologic and phylogenetic classification in Aphanizomenon flos-aquae strains isolated from the Nakdong River and to investigate the potential ability of the strains to produce toxins such as saxitoxin and cylindrospermopsin using target genes. The 16S rRNA and sxtA, sxtI, cyrA, cyrJ genes were analyzed on two strains (DGUC001, DGUC003) isolated from the Nakdong River. Morphological features of the strains were observed a shape of aggregated trichomes in parallel fascicles which can reach up to macroscopic size and a hyaline terminal cell without aerotope. In addition, the 16S rRNA phylogenetic analyses showed that the strains were identified as the same species with high genetic similarity of 98.4% and grouped within a monospecific andsupported cluster I of Aphanizomenon flos-aquae selected from GenBank of the NCBI. The cyrA and cyrJ genes encoding for the cylindrospermopsin-biosynthesis were not detected in the present study. The sxtA gene was in detected both the two strains, whereas the sxtI gene which had been suggested as a suitable molecular marker to detect saxitoxin-producing cyanobacteria was not found both the strains. Thus, the two strains isolated from Nakdong River were identified as the same species of Aphanizomenon flos-aquae Ralfs ex Bornet et Flahault 1888, the two strains were confirmed as potential non-producing strains of the saxitoxin and cylindrospermopsin.

• Restorative Dentistry and Endodontics
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• v.32 no.2
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• pp.102-110
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• 2007

The purpose of this study was to obtain the basic information for the improvement of dental environment by investigating the presence of methicillin- or vancomycin-resistant Staphylococcus aureus (MRSA or VRSA) isolated from dental health care workers (DHCWs) and environment of the Chosun University Dental Hospital (CUDH) and a private dental clinic (control group). Staphylococcus aureus (S. aureus) was isolated from anterior nares of 42 DHCWS and 38 sites, unit chairss, x-ray devices, computers, etc., at 10 departments of the CUDH and 20 DHCWs and 11 sites at the private dental clinic. S. aureus was isolated on mannitol salt agar plate and confirmed by PCR with S. aureus species-specific primer. Antimicrobial susceptibility test of clinical isolates of S. aureus against several antibiotics including methicillin (oxacillin) was performed by investigating minimum inhibitory concentration (MIC) using broth microdilution assay. In addition, PCR was performed to detect the methicillin- or vancomycin-resistant gene. The data showed that one strain of S. aureus was isolated from DHCWs of the CUDH and three strains of S. aureus was isolated from 3 samples of the private dental clinic, respectively. All of the isolates from the CUDH and the private dental clinic had resistance to penicillin G, amoxicillin and vancomycin and susceptibility to oxacillin and ciprofloxacin. The S. aureus strains were already obtained the resistance to penicillin G and amoxicillin. These results suggest that two dental clinics were under relatively safe environment.

• Korean Journal of Environmental Biology
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• v.26 no.2
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• pp.57-65
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• 2008

The effects of light quality and irradiance on the growth of centric diatom, Skeletonema costatum (Jinhae Bay strain) were investigated in the laboratory. At 20$^{\circ}C$ and 30 psu, the irradiance-growth curve showed the maximum growth rate of 1.17 day$^{-1}$ with half-saturation photon flux density (PFD) (K$_s$) of 92.4 $\mu$mol photons $m^{-2}s^{-1}$, $\mu$=1.17 (I-5.28)/(I+81.8), (r=0.98), and a compensation PFD (I$_0$) was 5.28 $\mu$mol photons $m^{-2}s^{-1}$. The 10 equated to a depth of 3$\sim$5 m from March to May, 11 m in June and 4 m from July to September in Jinhae Bay. These responses suggested that irradiance at the depth near the surface layer in Jinhae Bay would provide favorable conditions for S. costatum. To assess the effects of light (i.e. wavelengths) on the growth, nine wave-lengths were used ranging from near ultraviolet to near-infrared supplied by light emitting diode. At an irradiance level of 25 $\mu$mol photons $m^{-2}s^{-1}$, S. costatum grew under wavelengths of 405, 470, 505, 525, 568 and 644 nm, but did not grow at 590 and 623 nm; whereas S. costatum grew at all wavelengths at 100 $\mu$mol photons $m^{-2}s^{-1}$. This implies that S. costatum is likely to grow well in enclosed water bodies where suspended particles absorbs most of the blue wavelengths, and dominated by yellow-orange wavelengths.

• Journal of Life Science
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• v.20 no.1
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• pp.90-96
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• 2010

Menopause increases the onset of hypertension and heart disease. Whereas it increases the blood LDL-cholesterol, triglyceride and total-cholesterol levels, the HDL-cholesterol concentration is reduced. Accordingly, we examined the effect of internal organs of Todarodes pacificus (IOT) on improvement in blood flow ability and changes in serum lipid content by using ovariectomized rats. For this study, the following four groups of 9-week-old Sprague-Dawley strain female rats were evaluated over 6 weeks: normal rats (SHAM), ovariectomized rats (CON) and ovariectomized rats that were treated with IOT extracts. Ovary removal promoted platelet aggregability. However, IOT administration in the CON group after ovary excision resulted in a hinderance of coherence. The blood vessel passing time of ovariectomized rats was slower than the SHAM group. But the blood flow ability, which was slowed down for ovary removal, was improved by IOT administration. Serum triglyceride levels were significantly reduced by IOT administration. Moreover, blood HDL-cholesterol levels were reduced by ovary removal. However, IOT administration after ovary excision significantly increase HDL-cholesterol levels. The biological activity of IOT could be confirmed from these results. Moreover, IOT can be used in the development of functional foods which are meant to improve blood circulation and anti-platelet aggregation function. According to these results, we could know that IOT improved blood flow and anti-platelet aggregation. Therefore, it is expected that IOT can be used for the development of functional foods.

• KSBB Journal
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• v.18 no.6
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• pp.522-528
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• 2003

The purpose of this study is to inquire into molecular epidemiological characteristics of Vibrio parahaemolyticus. For this study, 120 strains(120 strains of Vibrio parahaemolyticus sampled from diarrhea patients) were examined and analyzed for biochemical characteristics, TDH (thermostable direct hemolysin) antibiotics sensitivity and detection of toxR, gyrE, tdh, and tds gents. G-S PCR (Group Specific Polymerase), PFGE (Pulsed-field Gel Electrophoriesis) methods were performed on the materials from patients were results. 1 Vibrio parahaemolyticus didn't grow in 0% density of NaCl, but the fact was found that those grew in 8% density of NaCl. 2. O：K serotypes of Vibrio parahaemolyticus was turned up in domestic patients was 17 types. Among those O3：K6 was the most, it was 68.3%. 3. In 18 kinds of antibiotic tests resistant against Ampicillin, Ticacillin was comparatively high. the case of resistant against Ampicillin, Ticacillin, Vancomycin at the multiple resistant was 52.5%. 4. Toxin gene tdh had only 109 strains among 120 ones isolated from patients held the genes of 199bp size, and 11 strains was negativity 5. In the test of Kanagawa toxic productivity, 107 strains among strains isolated from patients appeared to be positivity reaction 6. The strain that held trh toxin was only 3, and those among test strains had the genes of 250bp size and that had tdh, trh genes at a time were 3 strains, and TDH toxic productivity of those were 16 times, and it was weak. 7. Group Specific-PCR appeared to be useful in the confirmation of O3:K6 serotype interrelations. 8. Three strains which showed difference of 7 DNA sequence even in the same serotype were detected by the result of analyzing the regular gene, toxRS DNA sequence. These strains are differ from general strains which carry infection easily. 9. These mutual dose epidemiological relations were classified into smaller-parts through PFGE method. As a result of such classify, 3 findings were found. V. parahaemolyticus sampled from diarrhea patients were classified into 3 types. And third, the result obtained through PFGE method can be used as a useful tool in a point of molecular-epidemiological view.

• Tuberculosis and Respiratory Diseases
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• v.50 no.4
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• pp.473-483
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• 2001

Background : There are only a few studies regarding the causes of treatment failure for tuberculosis. Therefore, this study aimed to determine the causes of intractable tuberculosis. Methods : M. tuberculosis, differentiated MOTT (Mycobacterium Other Than Tuberculosis) were isolated, and the RFLP (Restriction fragments length polymorphisms) pattern was analyzed from 204 patients with pulmonary tuberculosis and 53 suffering from neck tuberculosis. The IL-$1{\beta}$, IL-12, $^*1\;IFN{\gamma}$ and $^*2\;TNF{\alpha}$ blood levels were measured. All patients were regularly followed for 18 months after treatment. Results : There was no correlation between the RFLP patterns of M. tuberculosis treatment failure. From the 204 cases, 31.9% were intractable. The characteristics of patients with intractable tuberculosis were old age, being male and recurrent cases. The causes of treatment failure were identified as follows ; a decrease in the IL-12(59.4%) concentration, drug resistant strain(54.7%), irregular medication(15.4%), MOTT(6.2%) and a heavy infection(4.6%). The causes of all cases of intractable tuberculosis could be investigated. The IL-12 concentration in the blood was significantly lower in the intractable cases, where it disclosed a maximum sensitivity(64.7%) and specificity(75.4%) at 165.0 pg/mL. Most of the 53 cases of neck node tuberculosis were treated successfully. Therefore, we were unable to analyze the cause of treatment failure. Conclusion : A decrease in the blood IL-12 concentration and drug resistant strains were identified as the most significant causes of treatment failure for tuberculosis. In Korea, infection by clusters were prevalent, but no difference in the clinical course between clusters and non-clusters could be found.

• Food Science and Preservation
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• v.11 no.4
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• pp.550-556
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• 2004

In the present study, we investigated the antimutagenic and cytotoxic effects of Acer ginnala Max. bark extract on S. typhimurium TA98, TA100 and cancer cell lines with Ames test and SRB assay, respectively. They were extracted with methanol and then fractionated using hexane, chloroform, ethyl acetate, butanol, and water to obtain the fractions. The inhibition rate of methanol ($200\;{\mu}g/plate$) of Acer ginnala Max. bark extract in the Salmonella typhimurium TA100 strain showed $83.3\%$ against the mutagenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). In addition, the suppression of methanol extract with same concentration of in the Salmonella typhimurium TA98 and TA100 strains showed $80.3\%\;and\;92.7\%$ inhibition against 3-amino-1,4-dimethyl-5H-pyrido-(4,3-b)indol (Trp-P-1), respectively. The cytotoxicity effects of Acer ginnala Max. bark extract against the cell lines with human lung carcinoma (A549), human gastric carcinoma (AGS), human hepatocellular carcinoma (Hep3B) and human breast adenocarcinoma (MCF-7) were inhibited with the increase of the extract concentration. The treatment of 1.0 mg/mL Acer ginnala Max. bark methanol extract of methanol showed strong cytotoxicities of $77.3\%,\;90.4\%,\;88.9\%,\;and\;83.7\%$ against A549, AGS, Hep3B and MCF-7, respectively.