• Title/Summary/Keyword: inhibiting

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Inhibiting Pattern of Dopachrome Formation as Influenced by Sodium Benzoate in Raw Potato Tubers (감자괴경에서 Sodium Benzoate에 의한 Dopachrome형성 억제 패턴)

  • Moon, Young-Sook;Lee, Mie-Soon
    • Korean Journal of Food Science and Technology
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    • v.17 no.3
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    • pp.232-236
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    • 1985
  • The inhibiting properties of sodium benzoate on the dopachrome formation were investigated with crude enzyme preparations from homogenized tissues of raw potato tubers. The % inhibition of dopachrome formation was increased with increasing concentrations of sodium benzoate and decreasing concentrations of substrate, 3,4-dihydroxyphenylalanine(DOPA). The inhibiting action was gradually reduced with increasing temperature. Dopachrome formation tended to be greatly inhibited in the range of pH 3-5, while it revealed a sharp increase above pH 6. The results suggested that sodium benzoate might compete with the substrate for the enzyme.

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Effectiveness of Different Classes of Fungicides on Botrytis cinerea Causing Gray Mold on Fruit and Vegetables

  • Kim, Joon-Oh;Shin, Jong-Hwan;Gumilang, Adiyantara;Chung, Keun;Choi, Ki Young;Kim, Kyoung Su
    • The Plant Pathology Journal
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    • v.32 no.6
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    • pp.570-574
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    • 2016
  • Botrytis cinerea is a necrotrophic pathogen causing a major problem in the export and post-harvest of strawberries. Inappropriate use of fungicides leads to resistance among fungal pathogens. Therefore, it is necessary to evaluate the sensitivity of B. cinerea to various classes of fungicide and to determine the effectiveness of different concentrations of commonly used fungicides. We thus evaluated the effectiveness of six classes of fungicide in inhibiting the growth and development of this pathogen, namely, fludioxonil, iprodione, pyrimethanil, tebuconazole, fenpyrazamine, and boscalid. Fludioxonil was the most effective ($EC_{50}$ < $0.1{\mu}g/ml$), and pyrimethanil was the least effective ($EC_{50}=50{\mu}g/ml$), at inhibiting the mycelial growth of B. cinerea. Fenpyrazamine and pyrimethanil showed relatively low effectiveness in inhibiting the germination and conidial production of B. cinerea. Our results are useful for the management of B. cinerea and as a basis for monitoring the sensitivity of B. cinerea strains to fungicides.

Effects of Serum Fractions Separated by Molecular Weight on the Development of Mouse Embryos Fertilized In Vitro (분자량에 따라 분획화된 혈청성분이 생쥐 체외수정란의 발생에 미치는 영향)

  • 한정호;정구민
    • Journal of Embryo Transfer
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    • v.9 no.1
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    • pp.127-137
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    • 1994
  • This study was carried out to investigate the inhibiting or promoting effect of fetal bovine serum fractionated by the molecular weight and to examine the effect of reconstruction of serum fractions on the development of 1- and 2-cell mouse embryos fertilized in vitro (IVEE) . The serum was separated by ultrafiltration or gel filtration methods and added in m-KRB medium for culture of IVFE. The developemental ability(cavitation and hatching) of embryos following culture of day 4 and 6 was compared among fractions. Small molecular weight fraction( <3 kDa) significantly inhibited the development of 1-and 2-cell IVFE to the blastocyst stages, compared with other fractions. One-cell IVFE were more sensitively damaged than 2-cell embryos by that fraction and arrested mainly at 2~4 cell stages. Moreover, small amount(<3%,v /v) of the inhibiting fraction acted even with protein rich fraction(100~30 kDa) and arrested the embryonic development. On the other hand, 100~30 kDa fraction promoted the embryonic development and no inhibiting effect was observed at the level of 50%(v /v) in culture medium In the experiment of gel filtraton, =30 kDa fraction showed the highest promoting effect on the embryonic development, but <4 kDa fraction inhibited significantly the development. These results suggest that serum contains not only small molecular weight inhibitory component(s) but also promoting one rather than albumin on embryonic development. And serum can be more effectively used in the IVF program after removal of inhibitory component(s) by one of above separation methods.

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Study on Feeding Habits of Micropterus salmoides in Habitat Types from Korea (서식처 유형에 따른 배스 Micropterus salmoides 식성의 차이)

  • Park, Jong Sung;Kim, Su Hwan;Kim, Hyun Tae;Kim, Jae Goo;Park, Jong Young;Kim, Hyeong Su
    • Korean Journal of Ichthyology
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    • v.31 no.1
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    • pp.39-53
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    • 2019
  • In order to compared the feeding habits of Micropterus salmoides according to the habitat types, the stomach content of a total of 306 M. salmoides were investigated from April to September 2016 in the stream and reservoir. As a result, the highest IRI (Index of relative importance) value in M. salmoides inhibiting the stream and reservoir were identified as fishes. However, the IRI value of crustaceans and insects as well as fishes in M. salmoides inhibiting the reservoir were high, showing a difference in IRI value of M. salmoides inhibiting the stream.

Development of Human Antibody Inhibiting RNase H Activity of Polymerase of Hepatitis B Virus Using Phage Display Technique (Phage Display 기법을 이용한 B형 간염 바이러스 Polymerase의 RNase H 활성을 억제하는 인간 단세포군 항체의 개발)

  • Lee, Seong-Rak;Song, Eun-Kyoung;Jeong, Young-Joo;Lee Young-Yi;Kim, Ik-Jung;Choi, In-Hak;Park, Sae-Gwang
    • IMMUNE NETWORK
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    • v.4 no.1
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    • pp.16-22
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    • 2004
  • Background: To develop a novel treatment strategy for hepatitis B virus infection, a major cause of liver chirosis and cancer, we aimed to make human monoclonal antibodies inhibiting RNase H activity of P protein playing in important role in HBV replication. In this regard, phage display technology was employed and demonstrated as an efficient cloning method for human monoclonal antibody. So this study analysed the usability of human monoclonal antibody as protein based gene therapy. Methods: RNase H of HBV was expressed as fusion protein with maltose binding protein and purified with amylose resin column. Single chain Fv (scFv) phage antibody library was constructed by PCR cloning using total RNAs of PBMC from 50 healthy volunteers. Binders to RNase H were selected with BIAcore 2000 from the constructed library, and purified as soluble antibody fragment. The affinity and sequences of selected antibody fragments were analyzed with BIAcore and ABI automatic sequencer, respectively. And finally RNase H activity inhibiting assay was carried out. Results: Recombinant RNase H expressed in E. coli exhibited an proper enzyme activity. Naive library of $4.46{\times}10^9cfu$ was screened by BIAcore 2000. Two clones, RN41 and RN56, showed affinity of $4.5{\times}10^{-7}M$ and $1.9{\times}10^{-7}M$, respectively. But RNase H inhibiting activity of RN41 was higher than that of RN56. Conclusion: We cloned human monoclonal antibodies inhibiting RNase H activity of P protein of HBV. These antibodies can be expected to be a good candidate for protein-based antiviral therapy by preventing a replication of HBV if they can be expressed intracellularly in HBV-infected hepatocytes.

Detection of Fungicidal Activities against Alternaria dauci Causing Alternaria Leaf Spot in Carrot and Monitoring for the Fungicide Resistance (당근검은잎마름병균 Alternaria dauci에 대한 살균제 효과 검정 및 병원균 집단에 대한 저항성 검정)

  • Do, Jiwon;Min, Jiyoung;Kim, Yongsu;Park, Yong;Kim, Heung Tae
    • Research in Plant Disease
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    • v.26 no.2
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    • pp.61-71
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    • 2020
  • With 32 fungicides, it was examined the inhibitory effects on the mycelial growth of Alternaria dauci KACC42997 causing Alternaria leaf blight of carrot. Showing the results of the agar dilution method, the fungicides belonging to C2, C5, G1, E2, and E3 group were excellent in inhibiting mycelial growth. Protective fungicides belonging to M group, except for iminoctadine tris-albesilate, and pyraclostrobin belonging to C3 group were effective in inhibiting spore germination of pathogens. The fungicides included into C2 group inhibiting succinate dehydrogenase activity and the G1 group inhibiting demethylase activity showed the excellent inhibitory effect on mycelial growth but the inhibitory effect of spore germination was very low. However, fluazinam belonging to C5 group was excellent in inhibiting spore germination as well as mycelial growth. Especially, when 100 ㎍/ml of fluxapyroxad belonging to the C2 group was treated, 47.1% of spore formation was inhibited on the medium. In comparison of the resistance factors of 3 fungicide groups, as G, C, and E group, in populations of A. dauci isolates collected from Gumi, Pyeongchang, and Jeju, resistance factor in the population of Jeju was the lowest. However, two isolates resistant to fludioxonil belonging to E2 group were found in the isolate group of Pyeongchang, and both showed cross-resistance to iprodione and procymidone.

Isolation of a Bacterium That Inhibits the Growth of Anabaena cylindrica

  • Kim, Chul-Ho;Leem, Mi-Hyea;Choi, Yong-Keel
    • Journal of Microbiology
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    • v.35 no.4
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    • pp.284-289
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    • 1997
  • A Gram (-), rod-shaped bacterium $2.3{\sim}2.8{\times}0.45{\mu}m$ in size which exhibited growth-inhibiting effects against a cyanobacterium (Anabaena cylindrica) was isolated from Daechung Dam Reservoir. This isolate was identified as Moraxella sp. and designated Moracella sp. CK-1. Hollow zones formed around bacterial colonies on the cyanobacterial lawn. In a mixed-culture of A. cylindrica and the isolate, each microorganism grew inverse-proportionally, and the cyanobacterial vegetative cells completely disappeared within 24 hours. On treatment with Moraxella sp. CK-1, cell walls of A. cylindrica disappeared, but sheathes remained in a more electron dense form. The unit membrane such as thylakoidal membrane was stable to bacterial lysing activity. This bacterium showed a broad action spectrum against cyanobacteria. The growth-inhibiting activity of Moracella sp. CK-1 against A. cylindrica is believed to be performed through the excretion of active substances.

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