• Biotechnology and Bioprocess Engineering:BBE
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• 제11권1호
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• pp.26-31
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• 2006

The saccharogenic liquid (SFW) obtained by the enzymatic saccharification of food wastes was used as a medium for production of bacterial cellulose (BC). The enzymatic saccharification of food wastes was carried out by the cultivation supernatant of Trichoderma harziaum FJ1 culture. Acetobacter xylinum KJ1 was employed for the BC production culture. The physical properties, such as polymerization, crystallinity, Young's modulus, and tensile strength, of BCs produced by three culture methods: the static cultures using HS (Hestrin-Schramm) as a reference medium (A) or the SFW medium (B), the shaking culture (C) or the air circulation culture (D) using the SFW medium, were investigated. The degrees of polymerization of BCs produced under the different culture conditions (A-D) showed 11000, 9500, 8500, and 9200, respectively. Young's modulus was 4.15, 5.0, 4.0, and 4.6 GPa, respectively. Tensile strength was 124, 200, 80, and 184 MPa, respectively. All of the BC had a form of cellulose I representing pure cellulose. In the case of the shaking culture, the degree of crystallinity was 51.2%, the lowest degree. Under the other culturing conditions, the trend should remain in the range of 89.7-84%. Overall, the physical properties of BC produced from SFW were similar to those of BC from HS medium, a commercial complex medium, and BC production by the air circulation culture mode brought more favorable results in terms of the physical properties and its ease of scale-up. Therefore, it is expected that a new BC production method, like air circulation culture using SFW, would contribute greatly to BC-related manufacturing.

• 동아시아식생활학회지
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• 제5권3호
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• pp.359-370
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• 1995

Kimchi is a traditional fermented vegetable in Korea. It has unique taste and flavor due to the variability of raw vegetable, subingredient and their ratio of combination. Fermentation method have very critical effect on these charicteristics. Overall taste of Kimchi is also influenced by texture. In this paper, the changes in texture of Kimchis were reviewed related to pectic substance, enzymatic activities and other chemical changes during the fermentation of Kimchi. Moreover, treatments to prevent softening of Kimchi texture such as preheating, CaCl$_2$ addition, their combination effect and chitosan addition were summarized from the literatures.

• BMB Reports
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• 제32권6호
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• pp.541-546
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• 1999

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 $60^{\circ}C$, 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.

• 한국미생물·생명공학회지
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• 제15권5호
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• pp.312-318
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• 1987

Streptomyces sp. J-350P가 생산하는 세포외 adenine deaminase의 adenine에 대한 Km 값은 5.8$\times$$10^{-5}$M로 측정되었으며 Arrhenius plots에 의한 효소의 활성화 에너지는 3.13 Kcal/mole로 측정되었다. 검토된 purine analogue중에서 6-chloropurine, 2,6-diaminopurine, 6-bromopurine, 4-aminopyrazolo (3,4-d) pyrimidine, 6-iodopurine, 그리고 8-bromoadenine은 본 효소에 의해 기질로 이용되었으며, 6-dimethylaminopurine은 adenine에 대한 경쟁적 저해제로 작용하였다. 본 효소는 0.1mM의 Fe$^{3+}$, Ag$^+$ 등에 의해 저해되었으며, 1mM의 $\alpha$, $\alpha$＇-dipyridyl, Pentachiorophenol, p-CMB 등에 의해 저해되었다.

• 한국미생물·생명공학회지
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• 제41권1호
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• pp.1-7
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• 2013

비휘발성, 비폭발성, 열적 안정성의 특성을 가지고 있는 이온성액체는 환경친화적인 용매이고, 또한 양이온과 음이온의 다양한 조합을 통해 사용 목적에 부합하는 이온성액체를 용이하게 합성할 수 있어 용매로서의 다양성으로 인해 청정 용매, 촉매, 추출 및 분리, 전해질 등의 분야에서 다양하게 응용되고 있다. 이에 본 논문에서는 이온성액체에 대한 기본 지식와 함께 현재 미생물생명화학공정에서 이온성액체가 용매로서 효과적으로 응용되고 있는 효소반응 분야, 단백질 재접힘 분야, 바이오매스 용해 및 활용분야에서의 최근 연구동향을 기술하였다.

• Bulletin of the Korean Chemical Society
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• 제34권10호
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• pp.2973-2977
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• 2013

In this study, we developed a liquid crystal (LC)-based optical sensor for monitoring enzymatic activity through orientational changes in liquid crystals (LCs) coupled to the properties of a poly-${\small{L}}$-lysine (PLL)-based polymeric membrane. We prepared a PLL-based polymeric membrane at the planar interface between the thermotropic liquid crystal and aqueous phases. The PLL-based polymeric membrane was obtained by contacting the PLL solution with water immiscible LCs, 4-cyano-4'-pentyl-biphenyl (5CB) doped with adipoyl chloride. We then investigated the membrane properties by examining the permeability of the membrane to phospholipids, 1,2-didodecanoyl-rac-glycero-3-phosphocholine (DLPC). The permeability of the membrane to transport phospholipids was monitored through the orientational transition of 5CB in contact with the dispersions of DLPC. Since trypsin can enzymatically catalyze the hydrolysis of PLL, we incubated an aqueous trypsin solution with the membrane for 2 h at room temperature to cause an increase in the permeability of the polymeric membrane to DLPC. As a result, a bright to dark optical shift of LCs was observed, which implied that an enzymatic reaction between trypsin and PLL-based membrane occurred. Two control experiments using chymotrypsin and bovine serum albumin (BSA) revealed no sign of improved permeability based on the orientational transition of LCs.

• 미생물학회지
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• 제28권3호
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• pp.229-235
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• 1990

평판배지상 세균 colony의 체외 세포 효소활성을 직접 측정할 수 있는 신속하고 정확한 방법에 대하여 기술하였다. 일반적으로 세균의 효소 특성을 살피기 위해서는 단백질, 전분, chitin, tween-80 등과 같은 고분자 물질을 첨가한 선택배지를 사용하고 있으나 그 방법상 여러 가지 문제점이 있다 그러므로 본 연구에서는 형광물질의 일종인 Methvlumbell liferyl(MUF) 기질이 일반적으보 사용되고 있는 천연 고분자 물질고 유사한가를 순수분리세균 균주를 이용하여 실험으로 검증하였다. MUF 기질 분해원리에 기초를 둔 기술한 새로운 방법은 순수 분리 균주는 물론 colony 계수에 사용되는 평판배지상에서도 세균의 체외세포 효소 특성을 정량적으로 측정 가능하게 한다. 본 새로운 방법을 이용하여 담수 생태계와 해양 퇴적토내 종속영양세균의 체외 효소 활성을 측정하여 고찰하였다.

• 한국의류학회지
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• 제37권8호
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• pp.1107-1116
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• 2013

This study examined the use of cutinase and lipase to process cotton/polyester blend fabric. Optimum treatment conditions for cutinase and lipase were investigated for cotton/polyester blend fabric. The properties of enzyme-treated fabrics were evaluated and compared in optimal treatment conditions. In addition, the possibility to provide an enzymatic finishing on blend fabrics using mixed enzymes in a two-step process were studied. The weight loss of cotton/polyester blend fabrics with Triton X-100 was 0.8% and the dyeing property of blend fabrics with calcium chloride increased by a factor of 1.2. The use of two enzymes in combination with cutinase and lipase in the presence of auxiliaries resulted in a cotton/polyester blend fabric weight loss of 0.8%. In addition, the dyeing properties of cotton/polyester blend fabrics improved by a factor of 1.5 and the moisture regain of cotton/polyester blend fabrics improved by a factor of 1.16. However, no marked loss was observed in tensile strength. The surface morphology of cotton/polyester blend fabrics is modified through a two-enzyme treatment. The treatment of cotton/polyester blend fabrics with cutinase and lipase maintains cotton strength and improves the moisture regain of polyester fabrics.

• Journal of the Korean Wood Science and Technology
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• 제52권2호
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• pp.101-117
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• 2024

The conversion characteristics of the major components of Liriodendron tulipifera were investigated during acid-catalyzed organosolv pretreatment. Glucan in L. tulipifera was slowly hydrolyzed, whereas xylan was rapidly hydrolyzed. Simultaneous hydrolysis and degradation of xylan and lignin occurred; however, after complete hydrolysis of xylan at higher temperatures, lignin remained and was not completely degraded or solubilized. These conversion characteristics influence the structural properties of glucan in L. tulipifera. Critical hydrolysis of the crystalline regions in glucan occurred along with rapid hydrolysis of the amorphous regions in xylan and lignin. Breakdown of internal lignin and xylan bonds, along with solubilization of lignin, causes destruction of the lignin-carbohydrate complex. Over a temperature of 160℃, the lignin that remained was coalesced, migrated, and re-deposited on the surface of pretreated solid residue, resulting in a drastic increase in the number and content of lignin droplets. From the results, the characteristic conversions of each constituent and the changes in the structural properties in L. tulipifera effectively improved enzymatic hydrolysis in the range of 140℃-150℃. Therefore, it can be concluded that significant changes in the biomass recalcitrance of L. tulipifera occurred during organosolv pretreatment.

• 한국식품조리과학회지
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• 제13권4호
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• pp.390-395
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• 1997

보리가루, 엿기름, 찹쌀가루의 수용성 추출물과 농축액이 효소적 갈변에 대한 억제 효과가 있는지를 PPO 활성에 대한 저해효과를 통하여 알아보았으며, PPO에 대한 저해효과가 가장 크게 나타난 엿기름 농축액의 갈변 정도와 환원성을 측정하고 이들 성질과 PPO활성에 대한 저해효과와의 상관관계도 조사하였다. 나아가 사과 슬라이스를 엿기름 농축액에 침지한 후 냉장하고 냉장 중 사과 슬라이스의 조직감과 갈변 정도를 조사한 결과는 다음과 같다. PPO에 대한 억제 효과는 엿기름 농축액이 가장 크게 나타났다. 엿기름 농축액은 가열 시간에 따라 당도, 갈변정도와 환원성은 증가하는 경향을 나타냈으며, PPO 활성은 감소하는 경향을 보였다 이러한 변화는 가열 60분까지는 서서히 변화하였으나 70분 이후에는 급격한 변화를 나타내었다. 또한 가열시간에 따라 엿기름 농축액의 pH는 감소하였다. 한편 엿기름 농축액에 침지한 사과 슬라이스의 냉장 저장중의 갈변정도는 6.9%로, 조직감의 변화는 14.3%로 가장 낮았다. 따라서 엿기름 농축액이 사과 슬라이스의 갈변 억제와 조직감 유지에 효과가 있는 것으로 나타났다.