• Journal of Microbiology and Biotechnology
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• v.25 no.7
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• pp.988-998
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• 2015

The filamentous fungus Aspergillus oryzae is a well-known expression host used to express homologous and heterologous proteins in a number of industrial applications. To facilitate higher yields of proteins of interest, we constructed the pAsOP vector to express heterologous proteins in A. oryzae. pAsOP carries a selectable marker, pyrG, derived from Aspergillus nidulans, and a strong promoter and a terminator of the amyB gene derived from A. oryzae. pAsOP transformed A. oryzae efficiently via the PEG-CaCl₂-mediated transformation method. As proof of concept, green fluorescent protein (GFP) was successfully expressed in A. oryzae transformed by pAsOP-GFP. Additionally, we identified a novel fungal α-amylase (PcAmy) gene from Penicillium sp. and cloned the gene into the vector. After transformation by pAsOPPcAmy, the α-amylase PcAmy from Penicillium sp. was successfully expressed in a heterologous host system for the first time. The α-amylase activity in the A. oryzae transformant was increased by 62.3% compared with the untransformed A. oryzae control. The PcAmy protein produced in the system had an optimum pH of 5.0 and optimum temperature of 30^oC. As a cold-adapted enzyme, PcAmy shows potential value in industrial applications because of its high catalytic activity at low temperature. Furthermore, the expression vector reported in this study provides promising utility for further scientific research and biotechnological applications.

• Journal of the Korean Society for information Management
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• v.37 no.2
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• pp.171-195
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• 2020

This study analyzed the collaborative process in time series by dismantling the edit log big data of Wikipedia Korea, a representative online collaboration community, from early 2002 to 2019. Analysis elements were extracted from the document edit records, formatted in standardized XML, and analyzed using Python and R. The ways of editors' contribution, the characteristics of data contents, and the trend of document creation were explained by the analysis. An active contribution of a small set of editors and a loose participation of the majority were revealed. In addition, sociocultural characteristics that appear in online communities were also found in Wikipedia Korea. A new, diverse set of external resources is necessary to sustain the collective intelligence. An effort to settle new editors into the wikipedia community and an openness through circulation structure to avoid the exclusiveness of the management group are suggested.