• Environmental Engineering Research
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• 제20권2호
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• pp.149-154
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• 2015

In recent years, immobilization agents were introduced into organic contaminated soil remediation and more and more materials were screened and used as the immobilizing carrier. However, effect of the decomposition of the immobilizing carrier on the bioremediation was rarely concerned. Therefore, the decomposition experiment of immobilizing carrier -corncob was carried out in the lab with the efficient degradation fungi - Mucor mucedo (MU) existing, and polycyclic aromatic hydrocarbons (PAHs) residues E4/E6 of the dissolved organic matter and microbial diversity during the decomposition process were studied. The results showed that: a) during the decomposition, the degradation of pyrene (Pyr) was mainly in the first 28 d in which the content of extractable Pyr decreased rapidly and the highest decrease was in the treatment with only MU added. b) Anslysis of E4/E6 changes showed that rich microorganisms could promote aromatization and condensation of humus. c) From the diversity index analysis it can also be seen that there is no significant difference in effects of PAHs on the uniformity of microorganisms. These results will not only be useful to have a better understanding of the bioavailability of contaminants adsorbed to biodegradable carriers in PAHs contaminated soil remediation, but also be helpful to perfect the principle of immobilized microbial technique.

• KSBB Journal
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• 제11권2호
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• pp.140-150
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• 1996

가정용 혈중 cholesterol 측정시스템을 개발하고자, 그 성능을 조절할 수 었는 벤수들의 최적화가 수 행되었다. 시스템의 주요 구성성분은 분석에 요구되는 효소들 (cholesterol esterase, cholesterol oxidase, 그리고 horseradish peroxidase) 이 부동화된 nitrocellulose membrane strip과 비 이온세척제 (Tri­t ton X-1OO) 및 발색물질 (3,3'-diaminobenzidine) 이 포함된 시료운반용액이다. 시료와 운반용액이 훈 합된 수용액을 membrane의 하단으로부터 흡수시키 면 모세관현상에 의해 시료는 부통화된 효소층으로 전달되어 연속효소반응이 일어난다. 마지막 효소반 응에서 발색물질은 산화되고 그에 따라 cholesterol 농도에 비례한 특정색이 신호로써 발생된다. 그 신호세기에 대해 효소들의 부동화조건과 운반용액의 화학조성이 최적화되었다. 최적조건 하에서 구성된 측정시스템의 농도응탑곡선은 혈중 cholesterol 농도를 측정하기에 충분히 높은 민감도를 나타내었다.

• Journal of Microbiology and Biotechnology
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• 제22권12호
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• pp.1673-1680
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• 2012

In this study, DEAE-corncobs [delignified corncob grits derivatized with 2-(diethylamino)ethyl chloride hydrochloride ($DEAE{\cdot}HCl$)] were prepared as a carrier to immobilize yeast (Saccharomyces cerevisiae) for ethanol production. The immobilized yeast cell reactor produced ethanol under optimized $DEAE{\cdot}HCl$ derivatization and adsorption conditions between yeast cells and the DEAE-corncobs. When delignified corncob grit (3.0 g) was derivatized with 0.5M $DEAE{\cdot}HCl$, the yeast cell suspension ($OD_{600}$ = 3.0) was adsorbed at >90% of the initial cell $OD_{600}$. This amount of adsorbed yeast cells was estimated to be 5.36 mg-dry cells/g-DEAE corncobs. The $Q_{max}$ (the maximum cell adsorption by the carrier) of the DEAE-corncobs was estimated to be 25.1 (mg/g), based on a Languir model biosorption isotherm experiment. When we conducted a batch culture with medium recycling using the immobilized yeast cells, the yeast cells on DEAE-corncobs produced ethanol gradually, according to glucose consumption, without cells detaching from the DEAE-corncobs. We observed under electron microscopy that the yeast cells grew on the surface and in the holes of the DEAE-corncobs. In a future study, DEAE-corncobs and the immobilized yeast cell reactor system will contribute to bioethanol production from biomass hydrolysates.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.229-229
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• 2005

• 한국미생물·생명공학회지
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• 제25권1호
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• pp.68-74
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• 1997

The conversion of D-sorbitol to L-sorbose by Gluconobater suboxydans was analyzed, and continuous production of L-sorbose was carried out in immobilized cell reactors. L-Sorbose production by high densities of resting cells was more effective than by conventional batch fermentations. Sorbitol dehydrogenase, an enzyme converting D-sorbitol to L-sorbose, did not suffer from substrate inhibition, but from product inhibition. When L-sorbose production was carried out with Ca-alginate-immobilized cells, about 60 g/l of L-sorbose was obtained. On the other hand, when the corn steep liquor (CSL) concentration of medium was reduced to 0.08%, 80 g/l of L-sorbose was obtained. Outgrowth inside the immobilized carriers was thought to block the pores of the carriers so that substrate could not easily diffuse through the carriers. Continuous production of L-sorbose was well accomplished in a bubble column reactor, and 6. 5 g/l.h of productivity and 81.2% of yield were obtained at a substrate feeding rate of 0.08h$^{-1}$ under the optimum conditions with carrier volume of 55% and aeration rate of 3 vvm.

• KSBB Journal
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• 제13권2호
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• pp.141-146
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• 1998

To remove the low concentration of methane biologically, a three phase fluidized bed bioreactor immobilized with Methylosinus trichosporium OB3b was used. Optimum pH, temperature and bed height for the operation were pH7.0, 30$^\circ C$ and 150cm, respectively. For the inlet methane concentration of 100-400ppm and flow rate of 2-4L/min, the removal efficiencies of the bioreactor using the activated carbon as a carrier were the range of 54-71%, whereas those using the biosand were the range of 45-56%. It was found that activated carbon was more efficient than the biosand for the removal of methane. When aeration tank was equipped with the bioreactor, the removal efficiency increased to 6-13% and maximum removal rate obtained in the experiment was 1184mg.CH$_4$/min.

• Journal of Industrial and Engineering Chemistry
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• 제67권
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• pp.326-332
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• 2018

In this study,the result shows that polyvinyl alcohol-sodium alginate (PVA-SA) gel bead crosslinked with sodium sulfate are better among the different methods by comparing the relative mechanical strength, mechanical strength swelling and expansion coefficient of beads in water. Subsequently, anammox biomass entrapment by PVA-SA gel was introduced into continuous stirred tank reactor (CSTR). After 24 operation days, the nitrogen removal efficiency achieved 60%, while the nitrogen loading rate (NLR) was $0.14kgN/m^3/d$ and the experiment data indicated that PVA-SA gel bead crosslinked with sodium sulfate can be used to initiate anammox process. Furthermore, it is an alternative for culturing anammox in a long-term operation.

• Applied Biological Chemistry
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• 제26권4호
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• pp.222-230
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• 1983

본 연구에서는 저자등이 분리한 바 있는 Streptomyces griseolus가 분비한 xylose 이성화 효소(D-xylose ketol isomerase, EC 5.3.1.5, 포도당 이성화 효소)의 고정화 및 이 고정화 효소에 의한 파일롯트 규모의 이성화당 생산에의 응용을 시도하였다. 세포내 분비된 Xylose 이성화 효소를 함유한 미생물 균체를 호모 게나이저로 $500kg/cm^2$압력하에 파쇄한 결과 원 효소 역가의 98.8%가 얻어졌고, lysozyme으로 분해 했을 때는 54.7%가 얻어졌다. 이 효소의 고정화를 위한 담체로서는 Diaion HP 20, Duolite A-7, Amberlite IRA 93 및 94와 같은 포리스형 수지류가 효과적임이 밝혀졌고, Amberlite IRA 93에 대한 재생 형태는 $BO_4--$가, Diaion HP 20에 대해서는 $HCO_3-$가 효과적이었다. Amberline IRA 93에 대한 고정화 최적 조건은 pH 8.0에 $55^{\circ}C$로서 80.6%의 효소 고저오하 수율을 나타내었으며 효소 활성 반감기는 $65^{\circ}C$에서 24일 이상이었다. Amberlite IRA 93에 효소를 탈착(脫着) 실험한 결과, 담체는 재 사용이 가능 하였으며 2,3,4,5회째의 효소의 재 고정화율은 각각 98.2, 93.3, 90.7 및 87.5%를 나타내었다. 고정화 효소의 최적 반응 온도는 $60{\sim}70^{\circ}C$로 원효소의 경우에 비하여 다소 낮아지면서 폭이 넓어졌으며, 최적 pH는 $8.0{\sim}8.3$으로 알카리 쪽으로 이동하였다. 파일롯트 규모로 본 고정화 효소 충전탑(내경 30cm, 높이 85cm)에 의한 이성화당의 생산을 시도하였던바, 고정화 효소(350 IXIU/ml-R) 1리터가 30일동안에 약 293리터의 이성화당을 생산할 수 있는 것으로 나타났다.

• KSBB Journal
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• 제5권3호
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• pp.241-246
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• 1990

Transgluaminase반응을 이용하여 ATP analog들$(C^8-ATP와 N^6-ATP)$을 casein에 고정화하였다. 고정화 ATP는 hexokinase에 의해 탈인산화되어 약55%가 ATP형으로 전환되었으며, 이는 acetate kinase에 의해 역으로 인산화되어 약80%가 ATP형으로 전환 되었다. $\beta$-Casein은 $$\alpha$_s_1-casein$에 비하여 glutamine 잔기의 수가 많으며,$N^6-ATP$의 경우 이의 alkyl carbamyl기와 casein의 carboxamide기 간의 정전기적 반발에 원인이 있는 것으로 보인다. ATP는 고정화하므로써 안정성이 증대되었으며, 고정화 ATP의 km치는 유리상의 ATP및 ATP analog의 그것과 비슷하였으나, 최대속도는 감소되었다. 고정하 ATP는 반응액에서 calcium의 첨가로 쉽게 침전되어 용액으로부터 거의 완전히 회수 되므로써, 반응액으로부터의 회수분리가 가능한 이점을 가졌다.

• 한국미생물·생명공학회지
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• 제7권1호
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• pp.1-8
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• 1979

혈액 및 생체반응물질등에 함유된 미량의 glucose를 효소적으로 간편하게 측량하기 위하여 먼저 고가의 glucose oxidase를 고정화 시켰다. 전리 방사선조사에 의하여 이 효소를 쉽게 고정화 시킬수 있는 방법과 그 알맞는 조건 및 높은 잔여 활성에 관한 결과는 다음과 같다. 1) 여러가지 monomer 및 polymer의 combination 중에서 AA-Bis, NK ester 23G, 물 (1:1:2)에 가용성 효소 1ml를 고정화 시켰을 경우를 비롯하여 GOD의 잔여활성이 50%이상인 여러 monomer Combination 찾았다 2) Carrier의 방사선중합에 필요한 선량은 100 krad 이상 이였으나, 400~500krad가 적당하였고, solvent는 toluene, n-haxane, petoleum ether chloroform 등을 이용할 때 고정화된 GOD의 잔여 활성 및 이화학적 성장이 좋았다. 3) GOD 고정화에 이용될 수 있는 완충 용액은 tris-glycerol buffer (pH 7.0)가 phosphate (pH 7.0) 보다 높은 활성을 보여 주었다. 4) 고정화된 GOD의 최적 pH는 6.0~6.5 또 온도는 30~4$0^{\circ}C$로서 가용성 효소보다 작용범위가 넓었고, pH 및 온도의 변화도 완만하였다. The author acknowledges with gratitude financial assistance from International Atomic Energy Agency, Vienna, Austria and also sincerely thanks Dr. K. Kawashima and his colleagues, National Food Research Institute, Tokyo, Iapan for encouragement and assistance.