• Journal of the Korean Society of Visualization
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• v.14 no.2
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• pp.3-11
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• 2016

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.05a
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• pp.105-105
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• 2009

• Proceedings of the KOSOMBE Conference
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• v.1992 no.11
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• pp.3-8
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• 1992

• Proceedings of the Korean Society of Life Science Conference
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• 2005.04a
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• pp.41-46
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• 2005

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• v.10 no.1
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• pp.49-53
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• 2005

• Journal of Biomedical Engineering Research
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• v.20 no.4
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• pp.365-399
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• 1999

• Proceedings of the KOSOMBE Conference
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• v.1993 no.11
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• pp.60-62
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• 1993

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.2
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• pp.130-135
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• 2000

The characteristics of two different modes of perfusion culture, intermittent and continuous bleedings, were investigated by culturing the hybridoma cells producing von Willebrand Factor (vWF) monoclonal antibody (McAb) in a 15 L bioreactor without clogging the filter. Both culture methods exhibited similar profiles of cell density and metabolite concentrations during the culture period at the cell concentration of around 1${\times}$107 cells/mL. When the perfusion rate was increased, the intermittrnt bleeding culture showed problems of ammonia accumulation and decrease of cell viability. The continuous bleeding culture in terms of nutrient consumption and metabolite production kinetics. But the analysis of specific oxygen consumption rate showed that the specific oxygen consumption rate of intermittent bleeding culture was similar to that of exponential growth phase. The continuous bleeding culture showed higher specific oxygen consumption rate of intermittent bleeding culture. finally we proved the possibility of long-term operation of continuous bleeding culture and produced approximately 40 g of vWF McAb in a 15L bioreactor after one-month operation.

• Mycobiology
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• v.47 no.4
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• pp.368-377
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• 2019

The genus Macrolepiota (Agaricales, Basidiomycota) is easy to recognize at the genus level because of big, fleshy basidiocarps with squamules covering the pileus; a single or double annulus; and big, thick-walled basidiospores with a germ pore. However, morphological identification is often unreliable in Macrolepiota due to similar morphological features among species. Due to the uncertainty of previous morphological identification in the genus Macrolepiota, it is necessary to re-examine Korean Macrolepiota using molecular data. We reexamined 34 Macrolepiota specimens collected from 2012 to 2018 in Korea using a reverse taxonomic approach, whereby species identification was first done based on the internal transcribed spacer (ITS) region analysis, followed by morphological confirmation. We identified the presence of four species: M. detersa, M. mastoidea, M. procera, and M. umbonata sp. nov. Two species (M. detersa and M. mastoidea) were previously unrecorded from Korea and M. umbonata is a new species. Detailed descriptions of all four species and taxonomic key are provided in this study. Macrolepiota procera and M. umbonata are distributed through the country, but M. detersa and M. mastoidea are distributed only in limited areas. According to our results, the combination of ITS locus and morphology proved to be a robust approach to evaluate the taxonomic status of Macrolepiota species in Korea. Additional surveys are needed to verify the species diversity and clarify their geographic distribution.

• Journal of Microbiology and Biotechnology
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• v.20 no.3
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• pp.574-578
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• 2010

Archaebacteria Sulfolobus acidocaldarius contains the highly thermophilic cytochrome P450 enzyme (CYP119). CYP119 possesses stable enzymatic activity at up to $85^{\circ}C$. However, this enzyme is still considered as an orphan P450 without known physiological function with endogenous or xenobiotic substrates. We characterized the regioselectivity of lauric acid by CYP119 using the auxiliary redox partner proteins putidaredoxin (Pd) and putidaredoxin reductase (PdR). Purified CYP119 protein showed a tight binding affinity to lauric acid ($K_d=1.1{\pm}0.1{\mu}M$) and dominantly hydroxylated (${\omega}-1$) position of lauric acid. We determined the steady-state kinetic parameters; $k_{cat}$ was 10.8 $min^{-1}$ and $K_m$, was 12 ${\mu}M$. The increased ratio to $\omega$-hydroxylated production of lauric acid catalyzed by CYP119 was observed with increase in the reaction temperature. These studies suggested that the regioselectivity of CYP119 provide the critical clue for the physiological enzyme function in this thermophilic archaebacteria. In addition, regioselectivity control of CYP119 without altering its thermostability can lead to the development of novel CYP119-based catalysts through protein engineering.