표면 개질을 통한 미생물합성 폴리에스테르의 효소분해속도 조절

이원기 한국환경과학회 2002 한국환경과학회지 Vol.11 No.12

Since the enzymatic degradation of microbial poly[(R)-3-hydroxybutyrate-co- hydroxybutyrate] (P(4HB-co-3HV)) initially occurs by surface erosion process, a degradation behavior could be controlled by the change of surface property. In order to control the rate of enzymatic degradation, plasma gas discharge and blending techniques were used to modify the surface of microbial P(3HB-co-3HV). The surface hydrophobic property of P(3HB-co-3HV) film was introduced by CF_3H plasma exposure. Also, the addition of small amount of polystyrene as a non-degradable polymer with lower surface energy to P(3HB-co-3HV) has been studied. The enzymatic degradation was carried out at 37℃ in 0.1 M potassium phosphate buffer (pH 7.4) in the presence of an extracellular PHB depolymerase purified from Alcaligenes facalis T1. both results showed the significant retardation of enzymatic erosion due to the hydrophobicity and the enzyme inactivity of the fluorinated- and PS-enriched surface layers.

Nanocages-augmented aligned polyaniline nanowires as unique platform for electrochemical non-enzymatic glucose biosensor

Ameen, S.,Akhtar, M.S.,Shin, H.S. Elsevier 2016 Applied Catalysis A Vol.517 No.-

<P>Non-enzymatic glucose biosensor was developed by utilizing the electrochemically grown nanocages-augmented polyaniline nanowires (NCa-PANI NWs) on silicon (Si) substrate. The NCa-PANI NWs were comprehensively analyzed in terms of the composition, optical, structural and the morphological properties. The grown NCa-PANI NWs were distributed uniformly on the entire surface of Si substrate, which confirmed the formation of highly dense NCa-PANI NWs networks during the electrochemical oxidation. A series of sensing performances for NCa-PANI NWs electrode were investigated by current (I)-voltage (V), cyclic voltammetry (CV) and amperometry measurements. The sensing results revealed that fabricated non-enzymatic sensor showed an excellent response to glucose with a stable, reliable, and high sensitivity of similar to 156.4 mA mM(-1) cm(-2), good detection limit of similar to 0.657 mu M with correlation coefficient (R) of similar to 0.99493. The fabricated glucose sensor based on NCa-PANI NWs electrode exhibited significant electrochemical stability, good reproducibility and the selectivity. (C) 2016 Elsevier B.V. All rights reserved.</P>

김 효소 가수분해물 첨가가 밀가루 반죽과 제빵 특성에 미치는 영향

유정희(Chung-Hee RYU),구재근(Jae-Geun KOO) 한국수산해양교육학회 2015 水産海洋敎育硏究 Vol.27 No.2

The effects of replacement of wheat flour with laver, Pyropia yezoensis, on the bread making properties and quality characteristics of bread were evaluated. The poor baking performance which arose from dried laver addition could be compensated by using exogenous enzymes (Flavouzyme) and baking aids. Laver hydrolysate was prepared by hydrolyzing laver using Flavouzyme for 9 hrs at 50℃. Doughs made by addition of laver hydrolysate (8% dried laver substitution level) showed excellent baking properties. Moreover, with the addition of glucose oxidase and hydro colloidal HPMC, loaf volume and crumb grain were improved for doughs containing laver hydrolysate. Both of intermediate fermentation and final proof time for doughs containing laver hydrolysate was shorter than that for conventional dough.

Production and Physicochemical Properties of Rice Bran Protein Isolates Prepared with Autoclaving and Enzymatic Hydrolysis

Yeom, Hye-Jung,Lee, Eun-Hye,Ha, Mi-Sun,Ha, Sang-Do,Bae, Dong-Ho The Korean Society for Applied Biological Chemistr 2010 Applied Biological Chemistry (Appl Biol Chem) Vol.53 No.1

The objectives of this study were to increase the protein purity in the rice protein isolate, and to enhance the functional properties of the extracted rice bran protein via enzymatic hydrolysis and/or high temperature treatment. Washing the isolates with 30% ethanol solution achieved significant improvements in the protein contents (77.62%) of the rice bran protein isolates. The highest improvement in solubility was detected in the isolate autoclaved after enzymatic hydrolysis, up to 97.4% at a pH of 10.0. A combined modification of the method involving autoclaving and protease-hydrolysis improved the emulsion activity of the isolate at pH values above 6.0. The autoclaving and enzymatic hydrolysis increased the foaming capacity of the isolate, but reduced the foam stability at all pH ranges except 5.0. Enzymatically hydrolyzed isolates evidenced lower minimum concentrations of gel formation proteins and higher gel strengths than were detected in the other isolates.

Production and Physicochemical Properties of Rice Bran Protein Isolates Prepared with Autoclaving and Enzymatic Hydrolysis

Hye Jung Yeom,Eun Hye Lee,Mi Sun Ha,Sang Do Ha,Dong Ho Bae 한국응용생명화학회 2010 Journal of Applied Biological Chemistry (J. Appl. Vol.53 No.1

Starch nanoparticles prepared by enzymatic hydrolysis and self-assembly of short-chain glucans

오선민,이병호,서동호,최현욱,김병용,백무열 한국식품과학회 2020 Food Science and Biotechnology Vol.29 No.5

Enzymatic hydrolysis and self-assembly areconsidered promising methods for preparation of starchnanoparticles (SNPs) because they are environmentallyfriendly, and time- and cost-effective. These methods arebased on the self-assembly of short-chain glucans releasedfrom the a-1,6 bonds in amylopectin. Since their discovery,many studies have described the structural and physicochemicalproperties of self-assembled SNPs. Self-assembledSNPs can be prepared by two methods: using only thesoluble portion containing the short-chain glucans, or usingthe whole hydrolyzate including both insoluble and solublefractions. Although the structural and physical properties ofself-assembled SNPs can be attributed to the compositionof the hydrolyzates that participate in self-assembly, thisaspect has not yet been discussed. This review focuses onSNPs self-assembled with only soluble short-chain glucansand addresses their characteristics, including formationmechanisms as well as structural and physicochemicalproperties, compared with SNPs prepared with totalhydrolyzates.

Food Science/Microbiology : Production and Physicochemical Properties of Rice Bran Protein Isolates Prepared with Autoclaving and Enzymatic Hydrolysis

Hye Jung Yeom,Eun Hye Lee,Mi Sun Ha,Sang Do Ha,Dong Ho Bae 한국응용생명화학회 2010 Applied Biological Chemistry (Appl Biol Chem) Vol.53 No.1

The objectives of this study were to increase the protein purity in the rice protein isolate, and to enhance the functional properties of the extracted rice bran protein via enzymatic hydrolysis and/or high temperature treatment. Washing the isolates with

유/무기 나노 복합체를 이용한 PAN계 탄소섬유 토우 유연 전극의 전기화학적 특성 평가 및 비효소 전기화학 센서의 활용

송민정 한국화학공학회 2024 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.62 No.3

This study is about the fabrication of a flexible electrode based on PAN-based carbon fibers tow using organic/inorganic nanocomposite and its application of non-enzymatic sensor. The organic/inorganic nanocomposite was composed of the conductive polymer polyaniline (PANI) and the metal oxide CuO. And glucose was used as the target of the electrochemical sensor. Commercialized CFTs were pretreated through heat treatment for desizing and electrochemical oxidation for activation. This nanocomposite was sequentially synthesized on the pretreated CFT surface using electrochemical polymerization and electrochemical deposition. Finally, the CFT/PANI/CuO NPs electrode was obtained. The electrochemical properties and sensing performance of the CFT/PANI/CuO NPs electrode were analyzed using chronoamperometry (CA), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The sensitivity of the CFT/PANI/ CuO NPs electrode was about 8.352 mA/mM (in a linear range of 0.445~6.674 mM) and 3.369 mA/mM (in a linear range of 6.674~50 mM), respectively. So, the CFT/PANI/CuO NPs electrode exhibited the enhanced sensing performances due to unique properties such as small peak potential separation, low electron transfer resistance, and large specific surface area. 본 연구는 유/무기 나노복합체를 이용한 PAN계 탄소섬유 토우(PAN-based carbon fibers tow) 기반의 유연 전극 제작 및 이를 활용한 비효소 전기화학 센서 개발에 대한 것으로, 전도성 고분자 polyaniline (PANI)와 금속 산화물 CuO을유/무기 나노복합체 소재로 사용하였으며 글루코스를 전기화학 센서 타겟으로 적용하였다. 전극 제작을 위해 시판된CFT는 열처리를 통한 사이징(sizing) 제거와 전기화학적 산화에 의한 표면 활성화의 전처리 공정을 거쳐 사용되었다. 유/무기 나노복합체는 전기화학적 중합 및 증착법을 통해 전처리된 CFT 표면 위에 순차적으로 합성되어 최종 CFT/ PANI/CuO NPs 전극이 제작되었다. CFT/PANI/CuO NPs 전극의 전기화학적 특성 및 센싱 성능은 시간대전류법와 순환전압 전류법, 전기화학 임피던스 분광법을 이용하여 분석되었다. CFT/PANI/CuO NPs 전극은 전도성 고분자과 금속산화물의 접목에 의해 전기 전도도 향상 및 우수한 전자 전달, 감응시간 단축, 비표면적 증가 등 개선된 전기화학적 특성과 증가된 감도, 넓은 선형 농도 구간, 높은 선택도 등 향상된 글루코스 센싱 성능을 보였다.

Morphological Property and In vitro Enzymatic Degradation of Modified Chitosan as a Scaffold

Bae, In-Ho,Jang, Won-Gu,Lim, Hyun-Pil,Park, Sang-Won,Lee, Kwang-Min,Park, Young-Joon,Park, In-Kyu,Jeong, Myung-Ho,Koh, Jeong-Tae 한국고분자학회 2011 Macromolecular Research Vol.19 No.12

Chitosan (CS) was proposed as a promising candidate scaffold for tissue engineering. However, some drawbacks of natural CS remain. The current study modified CS by conjugating thiol to CS polymer (Thio-CS) and substantiated its three-dimensional microstructure and physical properties such as swelling or degradation. The Thio-CS was obtained by CS modification using 2-iminothiolane-HCl (2-IT). Because of the formation of disulfide bonds between thiol moieties based on oxidation of the immobilized thiol groups of CS, Thio-CS exhibits in situ gelling properties according to the reducing amount of free thiol. The content of the thiol group was increased as the amount of 2-IT increased. The swelling test demonstrated that Thio-CS can absorb up to 3.5 times its weight of phosphate buffered saline within 1 h and that the pore size and amount significantly increased with incubation time. The Thio-CS enzymatic degradation rate according to velocity was investigated. The results showed that Thio-CS was more resistant to lysozyme as viscosity increased. Thio-CS sponges were fabricated using freeze-drying. The lyophilized Thio-CS had a homogeneous honeycomb-like shape, and its pores were relatively smaller (<2 ${\mu}m$) than those of unmodified CS (>2 ${\mu}m$). These results suggest that Thio-CS might be a candidate regenerative therapeutic device.

Biochemical Properties of a Chitin-Binding Class III Chitinase in Pumpkin Leaves

Lee,Sang Yeol,Kim,Min Gab,Lee,Ji Yeun,Jang,Ho Hee,Lee,Kyun Oh,Kim,Sun Chang The Korea Science and Technology Center 1999 BMB Reports Vol.32 No.6

When we compared the chitinase activity of various plant sources using colorimetric or active gel-staining assay methods, the specific activity of pumpkin leaves was the highest among the samples we analyzed. The highly active chitinase from pumpkin leaves (designated PL-ChtIII) was purified to homogeneity using affinity chitin gel and HPLC Mono-Q anion-exchange cloumn chromatographies. In contrast to other members of the class III chitinase family, PL-ChtIII showed a strong binding affinity to the regenerated chitin gel column. The apparent molecular weight of PL-ChtIII was estimated to be 29 kDa on SDS-PAGE gel, while its optimum pH and temperature were shown to be pH 6.0 and 60℃, respectively. Analyzing the reaction products of PL-ChtIII with swollen chitin as substrate, the dimer and tetramer of N-acetylglucosamine were produced as major products in the first hour of the enzymatic reaction along with a small amount of monomers and trimers. As the reaction time increased, dimeric N-acetylglucosamine became the predominant form of reaction product.