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Publication
Featured researches published by Heeyong Park.
Protein Expression and Purification | 2010
Sung Gu Lee; Hye Yeon Koh; Se Jong Han; Heeyong Park; Deuk Chae Na; Il-Chan Kim; Hong Kum Lee; Joung Han Yim
An endochitinase was previously purified and the gene was cloned from the psychrophilic Antarctic bacterium, Sanguibacter antarcticus (KCTC 13143). In the present study, recombinant endochitinase, rChi21702, was expressed using a yeast expression system (Pichia pastoris) and codon optimization. The expressed rChi21702 was purified by Phenyl-Sepharose column chromatography. Optimal expression yielded 1-mg purified enzyme from 1-L bioreactor culture. When p-NP-(GlcNAc)(2) was used as a substrate, the specific activity of the enzyme was determined to be 20U/mg. In vitro assays and thin-layer chromatography demonstrated that the recombinant enzyme has endochitinase activity that produces diacetyl-chitobiose as a dominant end product when chitooligomers, colloidal chitin, and the chromogenic p-NP-(GlcNAc)(2) are used as substrates. Optimal activity for rChi21702 was observed at 37 degrees C and a pH of 7.6. Interestingly, rChi21702 exhibited 63% of optimal activity at 10 degrees C and 44% activity at 0 degrees C. Taken together, the results indicate that rChi21702 has psychrotolerant endochitinase activity even after recombinant expression in yeast cells.
Biotechnology and Bioprocess Engineering | 2012
Heeyong Park; Sung Gu Lee; Tai Kyoung Kim; Se Jong Han; Joung Han Yim
An organic solvent for extracting prodigiosin from culture broth was selected and a test to determine the long-term stability of prodigiosin was performed to develop prodigiosin as a biological control agent against Chattonella antiqua, a harmful alga that can cause red tides. Prodigiosin was extracted using nine solvents, and the extracts were analyzed by liquid chromatography-mass spectroscopy. Acetone was selected as the best organic solvent because of its high extraction efficiency and less processing time. Stability tests for prodigiosin were performed at various temperatures, and algicidal activity against C. antiqua was also tested. Ultimately, > 98% stability was sustained after 30 days at 4°C, whereas < 30% stability was maintained after 30 days at 37°C. Although prodigiosin was kept for 30 days in an optimum organic solvent, its stability was safely maintained and algicidal activity was sustained at 4°C. These results indicate that acetone is a very useful extraction and storage solvent for prodigiosin.
Preparative Biochemistry & Biotechnology | 2016
Se Jong Han; Heeyong Park; Sunghui Kim; Dockyu Kim; Ha Ju Park; Joung Han Yim
ABSTRACT The objective of this study was to statistically optimize the mineral components of the nutritional medium required for enhancing the production of a cold-active extracellular serine-type protease, W-Pro21717, by the Antarctic bacterium Pseudoalteromonas arctica PAMC 21717. Skim milk was identified as the major efficient inducer. Among the 12 components included in the unoptimized medium, skim milk, NaCl, Na2SO4, Fe(C6H5O7) (ferric citrate), and KCl were determined, by the Plackett–Burman and Box–Behnken design, to have a major effect on W-Pro21717 production. Fed-batch fermentation (5 L scale) using the mineral-optimized medium supplemented with concentrated skim milk (critical medium component) resulted in a W-Pro21717 activity of 53.4 U/L, a 15-fold increment in production over that obtained using unoptimized flask culture conditions. These findings could be applied to scale up the production of cold-active protease.
Applied Microbiology and Biotechnology | 2011
Se Jong Han; Heeyong Park; Sung Gu Lee; Hong Kum Lee; Joung Han Yim
Archive | 2011
Joung Han Yim; Il Chan Kim; Sung Gu Lee; Doc Kyu Kim; Se Jong Han; Hyoung Seok Lee; Sung-Jin Kim; Tai Kyoung Kim; Pil-Sung Kang; Heeyong Park; Ha Ju Park; Suhkneung Pyo; Babita Paudel-Bhattarai
Archive | 2011
Joung Han Yim; Il Chan Kim; Sung Gu Lee; Dockyu Kim; Se Jong Han; Hyoung Seok Lee; Seung Jin Kim; Tai Kyoung Kim; Pil-Sung Kang; Heeyong Park; Ha Ju Park; Hye Yeon Koh; Mi Ra Park; Yu-Kyeong Park
Archive | 2011
Joung Han Yim; Il Chan Kim; Doc Kyu Kim; Se Jong Han; Hyoung Seok Lee; Bhattarai Hari Datta; Jung Eun Kim; Tai Kyoung Kim; Hyun Cheol Oh; Dong-gyu Jo; Cheolsoon Lee; Keun-sik Kim; Pyung Cheon Lee; Mi Ra Park; Yu-Kyung Park; Sung-Jin Kim; Pil-Sung Kang; Heeyong Park; Ha Ju Park
KSBB Journal | 2012
Heeyong Park; Tai Kyoung Kim; Se Jong Han; Joung Han Yim
Archive | 2011
Joung Han Yim; 임정한; Il Chan Kim; 김일찬; Sung Gu Lee; 이성구; Doc Kyu Kim; 김덕규; Se Jong Han; 한세종; Hyoung Seok Lee; 이형석; Sung-Jin Kim; 김성진; Tai Kyoung Kim; 김태경; Pil-Sung Kang; 강필성; Heeyong Park; 박희용; Ha Ju Park; 박하주; Suhkneung Pyo; 표석능
한국생물공학회 학술대회 | 2012
Se Jong Han; Heeyong Park; Sung Gu Lee; Tai Kyoung Kim; Joung Han Yim