• KSBB Journal
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• 제25권4호
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• pp.351-356
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• 2010

리르노셀룰로오스로부터 생산된 글루코오스와 자일로 오스의 혼합당을 동시에 발효하여 에탄올 생산을 증가시키며, 또한 에탄올 생산에서의 세포고정화의 영향과 ICR (immobilized cell reactor)을 이용한 혼합당에서의 에탄올 연속생산을 수행하였다. 고정화 P. stipitis를 이용한 플라스크에서 에탄올을 생산에 대한 혼합당과 질소원의 영향으로부터 5% 혼합당 (글루코오스/자일로오스 = 3:1)과 1% 질소원이 최적으로 타나났으며, 이때 생산된 에탄올 농도는 약 19-20 g/L이었다. 고정화된 P. stipitis을 이용하여 반복적 유가식배양 (repeated fed-batch)으로 에탄올을 생산하였을 때는 모든 당 농도에서 글루코오스는 빠르게 소비되었지만, 혼합당의 농도가 높아질수록 자일로오스의 소비속도는 점차적으로 감소하였다. 즉 혼합당 농도가 증가하면서 더불어 당 소비속도는 감소하였다. 또한 ICR에서 1% 혼합당을 연속적으로 공급하면서 에탄올을 안정적으로 생산하여, 에탄올 농도는 5.6 g/L이었고 에탄올 생산 속도는 0.13 g/$L{\cdot}h$이었다.

• KSBB Journal
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• 제5권2호
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• pp.167-173
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• 1990

Acetobacter aceti OLS-130cell을 Ca-alginate gel에 고정시킨 후 유동층 반응기를 이용한 연속적인 식초생산 가능성을 검토하였다. Working volume 2L규모의 유동층 반응기를 사용한 회분식발효를 발효온도 3$0^{\circ}C$, 통기량 1.0VVM에서 초기 ethanol 및 초산농도 3g/l와 27g/l에서 수행한 결과 free cell인 경우 발효 80시간 경과 후 23g/l의 초산이 생성되었으며, 이때 overall productivity는 0.31g/l-hr였고, 고정화 초산균의 bead를 250g/l로 하여 발효를 수행한 결과는 발효 48시간 경과 후 23g/l의 초산이 생성되어 overal productivity는 0.48g/l-hr로서 free cell일 때보다 약 1.5배 높았다. 위의 초산발효조건에서 배양 48시간 이후부터 연속발효를 실시한 결과 배양 90일까지 초산함량 50~55g/l의 식초를 연속적으로 생산하는 것이 가능하였으며, 이때 dilution rate는 $0.12hr^-1$로서 초산생산성은 약 2.76g/l-hr로 최대값을 유지하였으며 회분식 발효에서 free cell인 경우보다는 초산생산성이 약 8.9배, 고정화 세포인 경우보다 약 5. 8배 더 높았다.

• 한국미생물·생명공학회지
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• 제24권6호
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• pp.705-711
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• 1996

For the efficient production of 2, 5-diketo-gluconic acid (2, 5-DKG) by the immobilized cells of Erwinia herbicola, basic characteristics of 2, 5-DKG fermentation were analyzed and a process employing immobilized cell reactor was developed. The immobilized cells appeared to have diffusion limitation, and a maximum production of 2, 5-DKG was accomplished with 2 mm diameters of immobilized beads. Long-term stabilities of the immobilized cells could be maintained by addition of 1.75% (w/v) polypep- tone. Repeated batch fermentations with about 80 mol% of 2, 5-DKG yields were carried out six times in the fluidized bubble column reactors filled with immobilized cells at an aeration rate of 6 vvm.

• KSBB Journal
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• 제7권1호
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• pp.79-83
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• 1992

Erwinia rhapontici를 Ca-alginate에 고정화시켜 고정화 세포의 반응특성을 고찰하고, STR, PBR을 이용하여 Palatinose의 생산을 검토하였다. Free cell과 고정화 세포의 반응최적 pH는 5.5-6.0, 반응 최적온도는$30-35^{\circ}C$로 동일하였으나 고정화에 의해 pH 및 온도 범위가 보다 넓어졌고, 이때 Free cell및 고정화 세포의 겉보기 Km갑슨 각각 0.13, 0.28M이었다. STR을 이용한 Palatonose 생산시 고정화 세포의 반감기는 약 380 시간으로 낮았으나, PBR을 통해 30일까지 안정운전이 가능하였다. PBR 운전시의 운전온도 30, $33^{\circ}C$에서 Palatinose수율 및 고정화 세포의 안정성은 거의 동일한 결과를 나타내었으며 이때 PBR생산성은 약 120g/l$\cdot$h이었고, Pilot scale인 50L 까지 성공적으로 Scale up 되었다.

• Journal of Microbiology and Biotechnology
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• 제21권9호
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• pp.972-978
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• 2011

In this study, we investigated the performance of an immobilized ${\beta}$-galactosidase inclusion bodies-containing Escherichia coli cell reactor, where the cells were immobilized in alginate beads, which were then used in repeated-batch operations for the hydrolysis of o-nitrophenyl-${\beta}$-D-galactoside or lactose over the long-term. In particular, in the Tris buffer system, disintegration of the alginate beads was not observed during the operation, which was observed for the phosphate buffer system. The o-nitrophenyl-${\beta}$-D-galactoside hydrolysis was operated successfully up to about 80 h, and the runs were successfully repeated at least eight times. In addition, hydrolysis of lactose was successfully carried out up to 240 h. Using Western blotting analyses, it was verified that the ${\beta}$-galactosidase inclusion bodies were sustained in the alginate beads during the repeated-batch operations. Consequently, we experimentally verified that ${\beta}$-galactosidase inclusion bodies-containing Escherichia coli cells could be used in a repeated-batch reactor as a biocatalyst for the hydrolysis of o-nitrophenyl-${\beta}$-D-galactoside or lactose. It is probable that this approach can be applied to enzymatic synthesis reactions for other biotechnology applications, particularly reactions that require long-term and stable operation.

• KSBB Journal
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• 제10권3호
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• pp.241-248
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• 1995

염색가공 폐수 중 난분해성 물질이 PYA를 처리 하기 위하여, 한천-acrylamide를 이용한 bead를 제 조한 후 air-lift 반응기에서 연속실험을 행하였다. 합성폐수의 PYA놓도가 $3,100mg/\ell$. 체류시간 24hr일 때 유출수의 농도는 $4500mg/\ell$ 이며, 제거효율은 85% 이상을 나타내었다. 실제 호발폐수의 경우 PYA 및 COD농도가 $3,253mg/\ell$, $4,500mg/\ell$일 때, 체류시간 24hr에서 유출수의 농도는 $840mg/\ell, 480mg/\ell$이며, 제거효 율은 81.3%와 85.2%로 각각 나타났다. bead의 지름이 lmm일 때는 내부의 미생물 성장 이 양호하였으나 bead의 지름이 2mm일 때는 기질 과 산소전달저항에 의하여 반지름의 48% 이상은 미 생물의 성장이 저해를 받았다. 고정화 반응기에서 전체 기질 제거속도 중 bead 내 고정화 cell의 제거 분율은 평균 70%로 나타났다. 현탁 반응기에서 희석율 $0.083hr^{-1}$ 이상에서는 기질 이용속도가 감소하였으나 고정화 반응기에서는 희석율 $0.125hr^{-1}$까지 거의 선형척으로 증가하였다. PYA 제거속도식에서 포화상수 $K_s=6.60(g PVA/\ell)$와 최대 비기질 이용속도 k=0.175(g PVA/g cell.hr)를 얻었다.

• 한국미생물·생명공학회지
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• 제24권6호
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• pp.717-725
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• 1996

We have developed an efficient immobilized cell separator for continuous operation of immobilized fungal cell cultures, and applied this separator to actual fermentation process for the production of cyclosporin A (CyA), a powerful immunosuppressant. In the experiments employing highly viscous polymer (carboxymethyl cellulose) solution, the decantor showed good separating performances at high solution viscosites and fast dilution rates. Air duct and cylindrical separator installed inside the decantor turned out to play key roles for the efficient separation of the immobilized cells. By installing the decantor in an immobilized perfusion reactor system (IPRS), continuous immobilized culture was stably carried out even at high dilution rate for a long period, leading to high productivities of free cells and CyA. Almost no immobilized biomass existed in effuluent stream of the IPRS, demonstrating the effectiveness of the decan- tor system for a long-term continuous fermentation. It was noteworthy that we could obtain these results despite of the unfavorable fermentation conditions, i.e., reduced density of the biosupports caused by overgrowth of cells inside the bead particles and existence of high density of suspended fungal cells (10g/l) in the fermentation broth.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1979년도 추계학술대회 심포지움
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• pp.245.2-246
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• 1979

Heat treated whole cell of Aspergillus niger containing glucose oxidase-catalase system was entrapped in gelatin matrix crosslinked by glutaral-dehyde. The reaction characteristics of immobilized enzyme was studied in a fludized reactor. Heat treatment enhanced the stability and improved the properties of micellium for the immobilized process. The immobilized enzyme system showed the maximum activity at $35^{\circ}C$ and at pH 5.5. The optimum substrate concentration was 0.04M glucose. The activity of immobilized glucose oxidase was in proportion to the concentration of dissolved oxygen in reaction mixture as other reaction conditions were fixed. It was also demonstrated that the limiting factor for the activity of the immobilized glucose oxidase was the oxygen diffusion resistance which increases proportionally to the glucose concentration.

• Archives of Pharmacal Research
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• 제3권1호
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• pp.7-12
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• 1980

Ampliciline was synthesized from 6-amino-pencillanic acid (6-APA) and D-.alpha. phenylglycine methyl ester by using amplicilin synthesizing enzyme from Peudomonas melanogenum (IAM 1655). The whole cell enzyme was immobilized by entrapping it in the polyacrylamide gel lattices. The polymer used in the enzyme entrapment was made from 150 mg per ml of acrylamide monomer and 8 mg per ml of N, N'-methylenebisacrylamide. About 200 mg/whole cell enzyme was mixed in the polymer for entrapment. The maximal activity retention after immobilization was 56%. The optimal pH values for the whole cell enzyme and the immobilized whole cell enzyme were 6.0 and 5.9, respectively. The optimal temperature for the enzyme activity were the same for both type of preparations. The enzyme stabilities against pH and heat increased for immobilized whole cell enzyme. Immobilized cell was more stable especially in the acidic condition while both type were found to be very suceptible to thermal inactivation at a temperature above 4.deg.C. The kinetic constants obtained from Lineweaver-Burk plot based on two substate reaction mechanism showed somewhat higher value for immobilized whole cell enzyme as compared to the whole cell enzyme : the Km value for 6-APA were 7.0 mM and 12.5 mM while Km values for phenylglycine methyl ester were 4.5 mM and 8.2 mM, respectively. Using the immobilized whole cell enzyme packed in a column reactor, the productivity of ampiciline was studied by varying the flow rate of substrate solution. At the space velocity, SV, 0.14 hr$^{-1}$ the conversion was 45%. Operational stability found in terms of half life was 30 hr at SV = 0.2 hr.

• Journal of Microbiology and Biotechnology
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• 제9권4호
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• pp.482-487
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• 1999

The Pseudomonas sp. strain NGK1 (NCIM 5120) was immobilized in calcium alginate, agar, and polyacrylamide gel matrices. The salicylic acid-producing capacity of freely suspended cells was compared with immobilized cells in batches with a shake culture and continuous culture system in a packed bed reactor. Freely suspended cells ($4\times10^{10}cfu/ml$) produced 12 mM of salicylic acid, whereas cells immobilized in calcium alginate ($1.8\times10^{11}$cfu/g beads), agar ($1.8\times10^{11}$cfu/g beads), and polyacrylamide ($1.6\times10^{11}$cfu/g beads) produced 15, 11, and 16mM of salicylic acid, respectively, from naphthalene at an initial concentration of 25 mM. The continuous production of salicylic acid from naphthalene was investigated in a continuous packed bed reactor with two different cell populations. The longevity of the salicylic acid-producing activity of the immobilized cells from naphthalene was also studied in semi continuous fermentations. The immobilized cells could be reused 18, 13, and more than 20 times without losing salicylic acid-producing activity in calcium alginate-,agar-, and polyacrylamide-entrapped cells, respectively. The study reveals a more efficient utilization of naphthalene and salicylic acid production by the immobilized Pseudomonas sp. strain NGK1 as compared to the free cells.