• KSBB Journal
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• v.14 no.1
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• pp.36-44
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• 1999

The biosynthesis of Lovastatin, a cholesterol lowering agent formed by the filamentous fungus Aspergillus terreus, was investigated in shaking flask. The effects of essential elements in the experimental medium such as carbon, nitrogen, phosphate sources, and amino acids were examined to increase Lovastatin productivity. Lovastatin production in shaking flasks was 68 mg/L in the used medium. Effect of carbon source on Lovastatin production was performed. As a carbon source in the medium, 45 mL/L of glycerol increased the Lovastatin production up to 256 mg/L, which was found to be improved almost 3.5 times in comparison with that in common medium. The optimum concventration of peptonized milk as nitrogen source was obtained 30g/L on Lovastatin production. The severe inhibition of the cell growth and the Lovastatin production were observed in shaking flasks conducted at the medium contained ammonium carbonate as a nitrogen source. Lovastatin production various concentrations of several phosphate compounds was also examined. The addition of either potassium phosphate diabsic or sodium phosphate dibasic increased the Lovastatin production and the optimal level of potassium phosphate dibasic was 6 g/L. Even though Lovastatin contain methionine-derived methyl group, L-methionine and DL-methionine tend to diminish the Lovastatin production. Among the amino acids, L-histidine and L-tryptophan had a remarkable enhancing effect on the Lovastatin production. The optimal concentration of L-histidine and L-tryptophan was 6g/L.

• Journal of Microbiology and Biotechnology
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• v.19 no.3
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• pp.238-249
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• 2009

The genus Listeria consists of six closely related species and forms three phylogenetic groups: L. monocytogenes-L. innocua, L. ivanovii-L. seeligeri-L. welshimeri, and L. grayi. In this report, we attempted to examine the evolutionary relationship in the L. monocytogenes-L. innocua group by probing the nucleotide sequences of 23S rRNA and 16S rRNA, and the gene clusters lmo0029-lmo0042, ascB-dapE, rplS-infC, and prs-ldh in L. monocytogenes serovars 1/2a, 4a, and 4b, and L. innocua. Additionally, we assessed the status of L. monocytogenes-specific inlA and inlB genes and 10 L. innocua-specific genes in these species/serovars, together with phenotypic characterization by using in vivo and in vitro procedures. The results indicate that L. monocytogenes serovar 4a strains are genetically similar to L. innocua in the lmo0035-lmo0042, ascB-dapE, and rplS-infC regions and also possess L. innocua-specific genes lin0372 and lin1073. Furthermore, both L. monocytogenes serovar 4a and L. innocua exhibit impaired intercellular spread ability and negligible pathogenicity in mouse model. On the other hand, despite resembling L. monocytogenes serovars 1/2a and 4b in having a nearly identical virulence gene cluster, and inlA and inlB genes, these serovar 4a strains differ from serovars 1/2a and 4b by harboring notably altered actA and plcB genes, displaying strong phospholipase activity and subdued in vivo and in vitro virulence. Thus, by possessing many genes common to L. monocytogenes serovars 1/2a and 4b, and sharing many similar gene deletions with L. innocua, L. monocytogenes serovar 4a represents a possible evolutionary intermediate between L. monocytogenes serovars 1/2a and 4b and L. innocua.

• Food Science and Preservation
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• v.20 no.5
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• pp.650-658
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• 2013

Apple juices were sterilized by continuous pulsed electric field (PEF) treatments of pulse width of 25 ${\mu}s$ at electric field intensity of 20.0 kV/cm, and with the varied pulse frequencies of 35 Hz (40 kJ/L), 55 Hz (70 kJ/L), 72 Hz (100 kJ/L) and 85 Hz (130 kJ/L). The PEF treatments of apple juice reduced the microbial counts from 5.3 log CFU/mL of initial state to 3.0 log CFU/mL after PEF treatment at energy density of 130 kJ/L. Also yeast and fungi after PEF treatments were reduced from 5.3 log CFU/mL to 3.0 log CFU/mL and Escherichia coli were from 5.3 log CFU/mL of initial state to 4.7 log CFU/mL to < $10^1$ CFU/mL. The soluble solids and free sugars did not significantly differ (p<0.05) depending on conditions of PEF treatment. The total phenolic contents and antioxidant activity such as the DPPH and ferric reducing antioxidant power (FRAP) by PEF treatments were significantly partly reduced, but the PEF-reduced value came in smaller quantities than the heat treatment at $65^{\circ}C$. The iterative PEF treatments with pulse width of 25 ${\mu}s$ and pulse frequency of 85 Hz at electric field intensity of 20.0 kV/cm showed limited in microbial reduction. Also, total phenolic contents and antioxidant activity such as DPPH and FRAP, significantly decreased depending on treatment numbers of PEF (p<0.05).

• Journal of Life Science
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• v.18 no.4
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• pp.494-502
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• 2008

The anaphylaxis shock reaction on the whole cells of H. pylori exhibited a symptom of slight illness for the first and second medication of causing antigen at an antigen concentration of WC (H) $60\;{\mu}g/100\;{\mu}l$ for WC (H) and no anaphylaxis shock symptom was observed at an antigen concentration of $20\;{\mu}g/100\;{\mu}l$ for WC (L). In the case of anaphylaxis shock reaction on the crude urease, no symptom was observed at an antigen concentration of $20\;{\mu}g/100\;{\mu}l$ for both urease (L) and urease (H). In the heterologous passive cutaneous anaphylaxis (PCA) test using a guinea pig-rat, no positive reaction was detected in all the medication groups of WC (H), WC (L), urease (H) and urease (L). In the skin sensitization test, it was observed that the best antigen concentration not causing skin disorder at each of $80\;{\mu}g/100\;{\mu}l$, $40\;{\mu}g/100\;{\mu}l$, $20\;{\mu}g/100\;{\mu}l$, and $20\;{\mu}g/100\;{\mu}l$ was $40\;{\mu}g/100\;{\mu}l$.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.524-524
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• 2016

본 연구에서는 홍천 자운지구 고랭지 농업지역을 대상으로 장기간의 유역조사와 하천 모니터링을 통해 관측된 축척 데이터를 이용하여 비점오염저감 효과를 정량화하고 추후 모니터링 자료로서 탁수와 비점오염원 저감시설의 저감효과와 비점오염원의 효율적인 관리를 위한 기초자료를 제공하고자 하였다. 모니터링 결과 소양호 유역의 오염부하(1차 강우사상) 중 홍천군 자운지구의 유역단위 비점오염 저감효과의 분석에는 강우량과 단위면적당 오염부하를 이용하였으며, 자운천은 SS 5,396,761 kg, COD 82,261 kg, BOD 57,329 kg, T-N 68,711 kg, T-P 3,091 kg이었으며, 오염부하(2차 강우사상)는 SS 320,293 kg, COD 34,588 kg, BOD 22,350 kg, T-N 48,954 kg, T-P 640 kg으로 나타났다. 또한 소양호 유역의 EMC(1차 강우사상) 중 자운천은 SS 829.9 mg/L, COD 12.7 mg/L, BOD 8.8 mg/L, T-N 10.567 mg/L, T-P 0.475 mg/L 이었으며, EMC(2차 강우사상)는 SS 68.6 mg/L, COD 7.4 mg/L, BOD 4.8 mg/L, T-N 10.487 mg/L, T-P 0.137 mg/L로 나타났다. 소양호 유역의 단위면적당 오염부하(1차 강우사상) 중 자운천은 SS 402.0 kg/ha/event, COD 6.1 kg/ha/event, BOD 4.3 kg/ha/event, T-N 5.118 kg/ha/event, T-P 0.230 kg/ha/event 이었으며, 오염부하(2차 강우사상)는 SS 23.9 kg/ha/event, COD 2.6 kg/ha/event, BOD 1.7 kg/ha/event, T-N 3.646 kg/ha/event, T-P 0.048 kg/ha/event로 나타났다. 오염부하에서는 1차 강우에 비해 2차 강우에서는 SS 5,076,468 mg/L, COD 47,673 mg/L, BOD 34,979 mg/L, T-N 19,757 mg/L, T-P 2451 mg/L로 1차 강우사상에 비해 오염부하가 낮은 것으로 나타났다. 또한 EMC에서는 1차 강우에 비해 2차 강우에서는 SS 761.3 mg/L, COD 5.3 mg/L, BOD 4.0 mg/L, T-N 0.080 mg/L, T-P 0.338 mg/L로 1차 강우사상에 비해 EMC가 저감되었다. 단위면적당 오염부하는 1차 강우에 비해 2차 강우에서는 SS 378.1 mg/L, COD 3.5 mg/L, BOD 2.6 mg/L, T-N 1.472 mg/L, T-P 0.182 mg/L로 1차 강우사상에 비해 EMC가 저감되었다. 강우량과 강우강도 그리고 영농활동의 시기에 따른 EMC와 단위면적당 오염부하는 큰 차이를 보였으며, 예년에 비해 적은 강수량으로 인해 탁수와 비점오염부하의 배출이 상대적으로 적었던 것으로 판단된다. 소양호 유역과 같은 넓은 유역에서 시행되는 비점오염원의 저감연구는 오랜 시간 동안 자료를 축적해야 유의미한 평가가 이루어질 수 있으므로 장기적이고 지속적인 모니터링을 통한 유량 데이터 자료구축과 수질분석뿐만 아니라, 발생되는 비점오염 물질의 관리를 위한 체계적인 연구가 지속되어야하며, 아울러 농민의 인식도 변화 등을 포함하는 많은 인자들을 정밀히 조사하고 다각도로 분석하여 저감효과에 대한 지속적인 연구가 필요하다.

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.1
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• pp.52-62
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• 2015

Coagulating effects of eco-friendly coagulant materials such as zeolite, kaolinite, loess and chitosan upon sewage sludge were evaluated. And coagulating effects of the mixtures of those materials and polymer (polyacrylamide) were also investigated. Coagulating efficiency of loess was higher than that of kaolinite and zeolite at the treatment levels of 2,500~50,000mg/L. Coagulating efficiencies of zeolite, kaolinite and loess at the treatment level of 20,000mg/L were lower than that of 1,000 mg/L of polymer, which meant that single application of those materials in real plant were not feasible. At the treatment level of 1,000 mg/L, coagulating efficiency of Chitosan was much lower than that of polymer, which also meant that single use of chitosan in real plant could be unrealistic because of its high price. However, the application of the mixture of 'polymer 80mg/L + kaolinite or loess 500 mg/L + chitosn 10mg/L' or the mixture of 'polymer 80mg/L + kaolinite or loess 500mg/L' was promising way for coagulating sewage sludge.

• Journal of Life Science
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• v.15 no.5 s.72
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• pp.739-742
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• 2005

This experiment was carried out to clarify the effect of pyroligneous liquor and coconut water on plantlet multiplication and in vitro flowering of Dendrobium moniliforme. Plantlet growth and multiplication was good in 1.0 ml/L pyroligneous liquor treatment which was added to the basal media of 3 g/L hyponex and 4 g/L peptone ($H_{3} P_{4}$) containing 0.1 mg/L NAA and 1.0 mg/L kinetin. In the treatment of 30 ml/L coconut water showed good results on plantlet growth and multiplication. In vitro flowering showed highest rate in the treatment of 1.0 ml/L pyroligneous liquor and 30 ml/L coconut water which were added to the basal media of $H_{3} P_{4}$ containing 0.1 mg/L NAA and 1.0 mg/L kinetin.

• Korean Journal of Microbiology
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• v.28 no.2
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• pp.174-179
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• 1990

In order to overproduce L-phenylalanine, various kind of regulatory mutants were isolated from parental Escherichia coli K-12. MWEC 83 Producing 7.4g/l of L-phenylalanine has been derived as a tyrosine and tryptophan double auxotrophic mutant. To produce L-phenylalanine without adding L-tyrosine and L-tryptophan, revertant strain MWEC 101 was isolated from MWEC 83. Further various analogues and valine resistant mutants were isolated from MWEC 101. MWEC 101-5 was the most excellent strain that produced 17.9g/l of L-phenylalanine after having been cultivated for 54 hours in 15% glucose medium. It was disclosed that activities of rate-limiting enzymes including chorismate mutase and prephenate dehydratase in MWEC 101-5 were desensitized to 2mM L-phenylalanine in the enzyme reaction mixture and that activities level of 3-deoxy-D-arabino-heptulosonic acid-7-phosphate synthase and prephenate dehydratase were increased more than 20 times over those of the parental strain.

• Environmental Engineering Research
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• v.11 no.2
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• pp.77-83
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• 2006

The hot spring water of the north Jeonla province such as Wanggung, Jookrim, Seokjung, and Hwasim, has fluoride concentration of 3.9 mg/L, 12.7 mg/L, 1.9 mg/L, and 6.3 mg/L, respectively. These figures fairly exceed the Korean and WHO standard for potable water, which is 1.5 mg/L. Therefore, in this study, research on elimination of fluoride in a hot spring water of Jookrim region, which has the highest level of fluoride concentration level in the north Jeonla province, was carried out. In analysis of Jookrim hot spring water according to the water quality standard for potable water, pH was very high at 9.25 and the concentration of fluoride was 10 times higher than the standard at 18.2 mg/L. Other measurements were within the standard or not detected. After injecting 10g of activated carbon for elimination of fluoride, the fluoride concentration was measured at 13.5 mg/L, and when 70mL or more of alum 10 g/L solution was injected, the concentration was measured at 2.8 mg/L, and injecting 3g of lime was measured at 9 mg/L. Alum showed the best elimination performance among all individual injections. Injection of 25 mL of activated carbon and 100 mL of alum solution together reduced the fluoride concentration down to 1.3 mg/L, which is under the potable standard. Injection of lime 1g and 75 mL of alum 10 g/L solution together reduced fluoride concentration to 4.1 mg/L. From the modifying HRT, by using ion exchange resin column, the pH was stabilized when HRT was Imin and showed range of $6.7{\sim}7.8$. The fluoride concentration reduced gradually as the HRT increased, and satisfied the potable standard when HRT passed 6 min, and after 30 min HRT, the concentration of fluoride was 0.05 mg/L: almost eliminated.

• Journal of Korean Neurosurgical Society
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• v.44 no.5
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• pp.327-333
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• 2008

Objective: The purpose of this study is to verify the usefulness of the rabbit model for disc degeneration study. Materials: The L1-L2, L2-L3, L3-L4. or L4-L5 lumbar intervertebral disc (IVD) of 9 mature male New Zealand White rabbits were injured by inserting a 16-gauge needle to a depth of 5 mm in the left anterolateral annulus fibrosus while leaving L5-L6 IVD uninjured. Three other rabbits also received intradiscal injections of rabbit disc cells transfected with adenovirus and bone morphogenetic protein-2 (ad-BMP-2) at L4-L5 in addition to injury by 16-gauge needle at the L1-L2 level. Using digitized radiographs, measurements of IVD height were made and analyzed by using the disc height index (DHI). Magnetic resonance imaging (MRI) scans of the injured discs, injected discs, and uninjured L5-L6 discs were performed at 15 weeks post surgery and compared with preoperative MRI scans. Results: All twelve rabbits showed consistent results of disc degeneration within 15 weeks following annular puncture. DHIs of injured discs were significantly lower than that of the uninjured L5-L6 discs (p<0.05). The mean value of disc degeneration grade of injured discs was significantly higher than that of uninjured discs (p<0.05). The injection of disc cell transfected with ad-BMP-2 did not induce disc regeneration at 15 weeks after injection. Conclusion: This study showed that the injured disc had a significant change in DHI on simple lateral radiograph and disc degeneration grade on MRI scans within 15 weeks in all rabbits. Rabbit annular puncture model can be useful as a disc degeneration model in vivo.