유기용매 추출법에 의한 포플라의 전처리 및 당화

박정극,전영삼 한국생물공학회 1989 KSBB Journal Vol.4 No.3

Phenol / /;H^2O$를 유기용매로 사용하여 이태리 포플라(Populus euramericana)를 무촉매와 산촉매(HCI)하에서 170, 180, 190, 20$0^{\circ}C$에서 각각 30, 60, 90분간 전처리 하였다. 각 조건에서의 목분수율, 리그닌 제거율, 그리고 효소 가수분해에 의한 당화율을 비교 검토하였다. 무촉매하에서의 전처리 결과, 전체 목분수율은 71.5(17$0^{\circ}C$, 30분)에서 41.8%(20$0^{\circ}C$, 90분)의 분포를 보였고, 19$0^{\circ}C$, 60분 조건에서 가장 높은 전처리 효과를 나타내였는 바 이 때의 리그닌 제거율은 98.2%로서 거의 대부분이 추출되었으며 72시간 효소 가수분해 결과 생성된 전체 환원당 농도는 43.9g/1였고 전화율(당화율)은 83.4%였다. 이때 전체 환원당중 glicose의 농도는 36.2g/l로 82.5%를 차지하였다. 산촉매(HCL)를 사용하였을때는 무촉매에 비해 13.1$\pm$3.45%의 낮은 목분수율을 보였고 16.53$\pm$13.15%의 높은 리그닌 제거율을 나타내었다. 가장 높은 당화율은 17$0^{\circ}C$, 60분에서 전처리한 것으로 59.1%였다. 따라서 산촉매하에서의 당화율이 무촉매의 경우보다 훨씬 낮아 산촉매가 부적합함을 보였다. The effect of the pretreatment by solvent extraction on the saccharification of poplar (Populus euramencana) was studied. The solvent system was Phenol/H2O(Uncatalyzed)and Phenol/H2O/HCl catalyst system. When the poplar was pretreated by uncatalyzed system, the best result of the saccharification was total of 43.9 g/1 reducing sugar produced and 83.5% of carbohydrated conversion was obtained at 19$0^{\circ}C$, 60 minutes. Total wood yield and the lignin removal were 46.3% and 98.2% respectively. The use of acid catalyst was unsuitable to increase he efficiency of saccharification.

COLUMN 미래융합기술 (10) - 전자기파 에너지 이용한 신경질환 치료기술 개발한다

박정극,Park, Jeong-Geuk 한국과학기술단체총연합회 2011 과학과 기술 Vol.506 No.-

[송공사] 연꽃 만나고 가는 바람 같이

박정극 한국생물공학회 2014 BT NEWS Vol.21 No.1

콜라젠 및 세포의 응집정도가 쥐 일차 간세포의 간 특이기능에 미치는 영향

박정극,양성문,이두훈 동국대학교 산업기술연구원 1999 산업기술논문집 Vol.14 No.-

세포-세포 및 세포외 기질과의 상호작용은 배양 간세포의 분화와 기능을 유지하는데 필수적인 인자로 알려지고 있다. 본 연구에서는 간세포를 부유 배양하는 기간을 조절하여 다양한 응집 정도를 가지는 간세포 응집체를 얻을 수 있었으며 다양한 배양형태의 알지네이트와 콜라젠 젤에 고정화하였다. 콜라젠 젤에 고정화된 경우가 알지네이트 보다 전반적으로 간세포의 기능이 높게 나타났으며 15시간 정도 응집된 간세포가 높은 요소와 알부민 분비능을 나타내었다. 간세포를 효과적으로 배양하기 위해서는 콜라젠과 같은 세포외 기질 성분과 적당한 정도의 세포간 접촉이 필요함을 알 수 있었으며 이는 생물학적 인공간을 개발하는데 매우 중요한 설계요소이다. Cell-cell interaction and extracellular matrix(ECM) are believed to play essential roles during in vitro culture of primary hepatocytes in the control of differentiation and the maintenance of tissue specific functions. Hepatocyte aggregates were taken from the spinner flask four times at different culture periods of 1(1-4cells), 6(linear aggregate), 15(irregular rugged aggregate) and 48hours(round spheroid). Hepatocyte aggregates embedded in collagen gel showed higher viability and liver specific activities than those embedded in alginate. Irregular rugged aggregate(15hours) showed higher viability than single cell or small aggregates at the end of culture. Liver-specific activities of aggregates showed a tendency to increase as the degree of cell-cell interaction was increased.

Effects of Mechanical Stimulation on the Proliferation of Bone Marrow-derived Human Mesenchymal Stem Cells

박정극,송계용,권순용,Kyung-Min Choi,Young-Kwon Seo,윤희훈,Hwa-Sung Lee 한국생물공학회 2007 Biotechnology and Bioprocess Engineering Vol.12 No.6

To support and enhance the in vitro growth and activity of mesenchymal stem cells (MSCs), the cell culture medium may be supplemented with various proteins and factors to mimic the physiological environment in which the cells optimally proliferate and differentiate. In this study, the effects of mechanical factors on cellular metabolic responses were investigated experimentally using a bioreactor. The effects of various chemical factors, such as growth factors, cytokines, and hormones, were also investigated. Based on previous reports demonstrating the important roles of mechanical factors in the growth and activity of MSCs, we sought to evaluate the effects of mechanical stimuli on the proliferation of bone marrow-derived MSCs using a cell training bioreactor that imposed cyclic mechanical stretch, with parameters of 240 min/day, 0.03 Hz, and 5~15% strain. The application of cyclic stretch (5~15% strain) to the MSCs enhanced their proliferation during the early stage (3 days), but not the late stage (14 days), of batch culture. Mechanical stretch did not increase the release of lactate dehydrogenase (LDH) from the MSCs during culture. Appropriate levels of mechanical stretch (5~10% strain) increased collagen synthesis, but did not alter MSC surface antigen expression. It is thought that the appropriate level of mechanical stretch was able to serve as a potent positive modulator of MSC proliferation during the initial stages of culture.

유기용매 추출법에 의한 포플라의 전처리 및 당화 조건의 최적화

박정극,전영삼 東國大學校 1990 論文集 Vol.29 No.-

The effect of the pretreatment by solvent extraction with various solvent on the saccharification of poplar (Populus euramericana)was studied. The solvent system was phenol/H_2O (uncatalyzed, HCl and NaOH catalyzed), butanol/H_2O, ethanol/H_2O and ethylendiamine/H_2O solvent system. When the poplar was pretreated by phenol/H_2O uncatalyzed system, the best result of the enzymatic saccharification was total of 43.87 g/L reducing sugar produced and 83.35% of carbohydrated conversion was obatined at 190℃, 60 minutes. Total wood yield and the lignin removal were 46.3% and 96.17%, respectively. The use of acid, base catalyst and the others solvents was unsuitable to increase the efficiency of saccharification.

산소전달계수 및 경험적 기질공급방법이 Baker's Yeast 의 유가식배양에 미치는 영향

박정극,윤문영 한국화학공학회 1999 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.37 No.1

Baker's yeast 유가식배양에서 최적의 수율과 생산성을 위하여 K_La(산소전달계수)와 3가지 경험적 기질공급방법의 영향을 조사하였다. 발효기내의 교반속도(100에서 600rpm)와 통기속도(1.0, 1.5, 2.0vvm)를 변화시키면서 K_La값을 측정하였고, 통기속도는 1.5vvm으로 일정하게 유지하고 각각의 교반속도(300에서 600rpm)에서 유가식배양을 실시하여 수율과 생산성을 조사하였다. K_La값은 교반속도와 통기속도에 비례하여 빠르게 증가하였다. 기질공급 pattern은 sigmoidal한 공급이 최적으로 나타났고, 최적의 총 기질공급량과 생산성은 K_La값에 크게 의존하였으나 500rpm부터는 일정한 값을 유지하였고, 수율을 K_La값이 증가함에 따라 약간씩 감소하는 경향을 나타냈다. 이것은 molasses 투입량 증가에 의한 molasses내에 존재하는 저해작용물질축적과 발효대사산물의 축적, 점도의 증가, cell농도의 증가 등에 의해 cell 성장속도와 산소전달속도가 감소한 것으로 사료되고, 본 발효기는 500에서 600rpm부근에서 운전하는 것이 최적조건으로 판단된다. The effect of K_La(Oxygen Transfer Coefficient) and substrate feeding policy on the optimum cell yield and productivity was investigated in the baker's yeast fed-batch cultivation. K_La was measured at various agitation speed(100 to 600 rpm) and aeration rate (1.0, 1.5, 2.0 vvm), and the cell yield and productivity of fed-batch cultivation was determined at each agitation speeds (300 to 600 rpm) and constant aeration rate (1.5 vvm). K_La value was increased proportionally with increasing agitation speeds and aeration rate. Substrate feeding pattern was optimum in sigmoidal feeding. The optimum total fed-sugar and productivity was largely dependent on the K_La and did not change at above 500rpm, and the cell yield was decreased gradually as the K_La increased. It is considered that the increase of the accumulation of inhibitory substances in the molasses by the increase of molasses feeding, the accumulation of fermentation metabolites, the viscosity and cell concentration of fermentation broth, and so forth was decreased the cell growth rate and oxygen transfer rate. So, the optimum operation condition of this fermentor was estimated to near 500 to 600 rpm.

아시아 생물공학 연합체 (AFOB) 본부 사무국의 개소식에 즈음하여

박정극 한국생물공학회 2010 BT NEWS Vol.17 No.2

Improved Isolation of Outer Root Sheath Cells from Human Hair Follicles and Their Proliferation Behavior under Serum-free Condition

박정극,김영진,송계용,유보영,Youn-Ho Shin,윤희훈,Sung-Joo Hwang 한국생물공학회 2007 Biotechnology and Bioprocess Engineering Vol.12 No.1

Hair follicle is a small but very complex and dynamic miniorgan of the human body. It is easy to isolate and culture mesenchymal cells but not epithelial cells of hair follicle. It is necessary for intact and healthy outer root sheath (ORS) cells to be isolated and cultured. In this study we developed an appropriate isolation method to yield 6.4 ± 0.75 × 104 cells/hair follicle, which is about 9-fold comparing to our previous data. This yield was achieved by modifications such as different kinds of enzyme uses, fragmentation, and mechanical stimuli. Especially we detected that the different kinds of isolation enzyme could affect proliferation of ORS cells during primary culture. In addition, bovine pituitary extract (BPE) was needed for ORS cells to proliferate and to form colonies under serum-free, feeder layer-free culture condition, but type I collagen as a substratum did not have any positive effect. Moreover, ORS cells under BPE-added condition contained stem/progenitor cells expressing β1-integrin, CK19, and CD34. These results can provide useful cell culture information, not only in the study of hair biology but also in the field of tissue engineering and cell therapy for the treatment of alopecia.

150MW(F급) 가스터빈 수소혼소 리트로핏 기술개발 및 실증

박정극,최낙정,박세익,박성욱,권경원,이동훈,윤용일 한국유체기계학회 2023 유체기계 연구개발 발표회 논문집 Vol.2023 No.7