• KSBB Journal
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• 제24권1호
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• pp.70-74
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• 2009

본 연구에서는 음식물쓰레기를 당화시키기 위해 섬유소분해효소를 효율적으로 배양하고자 먼저 refill하는 멘델배지의 농도를 0.5%로, 새로운 배지의 주입시간을 12시간으로 결정하였다. Flask 레벨에서는 fill-and-draw 방법으로 12시간 단위로 연속배양한 결과, amylase 활성은 300시간까지 1.0 U/mL 내외로 유지되었으며, FPase 활성은 156시간까지 0.40 U/mL 이상으로 유지되었다. 이때의 효소생산성은 amylase 3.49 U/L. hr, FPase 1.02 U/L. hr 이었다. 10 L에서는 batch, fed-batch, fill-and-draw 방법으로 효소를 생산한 결과 batch에서 가장 높은 효소생산성을 나타내었으며, 그다음은 fed-batch 이었다. Batch에서의 효소생산성은 amylase 42.30 U/L. hr, FPase 5.60 U/L. hr, fed-batch에서는 각각 23.03, 2.76 U/L. hr 이었다. 그리하여 T. inhamatum KSJ1을 이용한 섬유소분해효소의 연속배앙에서 10 L 생물반응기에서 fed-batch 빙법이 가장 효율적이었다.

• KSBB Journal
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• 제8권2호
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• pp.164-171
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• 1993

Methylomonas mucosa를 이용하여 세포외 다당류의 생산을 알아보았다. 본 미생물은 성장을 위해 메탄올을 탄소원으로 이용하여 세포외 다당류를 생산한다. 효과적인 발효 공정 시스템의 개발올 위해 회 분식, 유가식, 연속식 배양을 수행하여 각각의 당류 에 대한 생산성을 알아보았다. 플라스크 배양에서 메탄올이 약 1 % (v/v) 이상에서 다당류의 생산과 세포의 성장은 저해되었다. 1% (v/v)에서 최대 비성장속도를 나타내었고 C/N 비율이 높을수록 다당류의 생산은 많았다. 다당류의 생산에 $Mg^{2+}$ 이온 농도가 크게 영향을 줌을 확인할 수있었다. 유가식 배양에서는 다당류의 농도가 회분식에 비 해 4배 이상 높았으나 수율은 오히려 감소하였다. 연속주입을 통한 유가식 배양은 간헐적 주업방법보다 생산성이 높았다. 이는 간헐적 주입에서 나타날 수 있는 메탄올에 의한 제한이나 저해가 없었기 때 문으로 보여진다. 연속조엽은 산소 제한을 피하기 위해 순수산소를 공급하였다. 희석률이 O.21h-1까지 증가하여도 수융 과 생산성은 증가하였다. 생산된 다당류 용액의 점도는 다당류의 증가에 따라 지수적으로 증가하였다.

• KSBB Journal
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• 제6권4호
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• pp.389-394
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• 1991

Emulsan is an extracellular emulsifying agent produced by the hydrocarbon-degrading Acinetobacter species RAG-1. In this study emulsan production of Acinetobacter calcpaceticus RAG-1 was investigated under various culture modes such as batch, fed-batch, membrane cell recycle, and continuous culture. The productions of emulsan under both ethanol-sufficient fed-batch and membrane cell recycle cultures were all 15.0U/ml, which was 53% increase in emulsan activity compared to that of pH controlled batch culture. Emulsan production was found to be strongly dependent on the residual ethanol concentration. In continuous culture the emulsan productivity increased with dilution rate.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.338-341
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• 2000

An internal membrane bioreactor system was employed for continuous succinic ac id production from glucose in order to prove its performance and practicality. Succinic acid-producing Anaerobiospirillum succiniciproducens required more $CO_2$ for the proper growth and succinic acid production in cell recycled continuous culture than in batch culture. The maximum productivity obtained in cell recycled continuous culture was about 3.3 g/L-h which was ca. 3.3 times higher than that obtained in batch culture.

• 한국미생물·생명공학회지
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• 제20권2호
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• pp.196-202
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• 1992

Zooloea ramigera 115를 사용하여 생물응집제로서 사용되는 생물고분자생산 실험을 하였다. 생물고분자 생산을 높이기 위하여 회분식, 유가배양, 연속배양방법을 사용하였다. 탄소원으로는 포도당, 유당, 당밀, 유청을 사용하였다. 기질이 포도당의 경우에는 C/N배 98일 때 생물고분자 생산 효과가 좋았으며, 유당의 경우에는 C/N비 30, 당밀과 유청의 경우에는 C/N비 60일 때 생물고분자 생산이 가장 좋았다. 유가배양 방법이 회분식 배양방법 보다 최종 생물고분자 생산이 우수하였다. C/N비를 달리한 2단계 연속 배양방법으로 생산성을 향상시켰다. 당밀의 경우 0.048$hr^{-1}$의 희석속도에서, 유청의 경우 0.096$hr^{-1}$에서 생산성이 가장 좋았다.

• Journal of Microbiology and Biotechnology
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• 제2권4호
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• pp.284-287
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• 1992

Repeated-batch and continuous cultures of Lactococcus sp. 1112-1 were carried out for bacteriocin production using a glucose-casein medium. Repeated-batch culture did not efficiently enhanced the bacteriocin production. Continuous production was possible at the dilution rate of 0.4 $h^{-1}$. Maximum specific production rate ($Q^p$), bacteriocin production and biomass at the dilution rate were 347, 136 IU/g/h, 2, 121 IU/ml and 2.45 g/L, respectively.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권6호
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• pp.522-527
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• 2005

Various processes which produce L-lactic acid using ammonia-tolerant mutant strain, Rhizopus sp. MK-96-1196, in a 3L airlift bioreactor were evaluated. When the fed-batch culture was carried out by keeping the glucose concentration at 30g/L, more than 140 g/L of L-lactic acid was produced with a product yield of 83%. In the case of the batch culture with 200g/L of initial glucose concentration, 121g/L of L-lactic acid was obtained but the low product yield based on the amount of glucose consumed. In the case of a continuous culture, 1.5g/L/h of the volumetric productivity with a product yield of 71% was achieved at dilution rate of $0.024\;h^{-1}$. Basis on these results three processes were evaluated by simple variable cost estimation including carbon source, steam, and waste treatment costs. The total variable costs of the fed-batch and continuous cultures were 88% and 140%, respectively, compared to that of batch culture. The fed-batch culture with high L-lactic acid concentration and high product yield decreased variable costs, and was the best-suited for the industrial production of L-lactic acid.

• KSBB Journal
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• 제25권5호
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• pp.471-477
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• 2010

In order to improve bio-ethanol productivity by various cultivation methods in this paper, the culture modes using food wastes, such as batch culture, high-cell-density fermentation, SSF (simultaneous saccharification and fermentation) by fill & draw, continuous culture by fill & draw were performed and their productivities were compared. SSFs by fill & draw were performed by continuous decompression using 1 L evaporator system, and by 10 L bioreactor without decompression. In addition, the continuous cultures by fill & draw mode using SFW (saccharafied food wastes) medium were performed by changes of 40% culture broth with intervals of 12 h (0.03 $h^{-1}$), 6 h (0.07 $h^{-1}$), 3 h (0.13 $h^{-1}$). Consequently, productivities of bio-ethanol were 2.52 g/L-h and 1.30 g/L-h in batch culture and high- cell-density fermentation, respectively. The productivities of SSF by fill & draw showed 2.24 g/L-h and 2.03 g/L-h in continuous decompression with 1 L evaporator and 10 L bioreactor without decompression, respectively. Also, the productivities in continuous culture by fill & draw modes showed 2.02 g/L-h, 4.07 g/L-h and 6.25 g/L-h by medium change with intervals of 12 h, 6 h, and 3 h, respectively. In conclusion, the highest ethanol productivity was obtained in the continuous culture mode by fill & draw with dilution rate of 0.13 $h^{-1}$.

• Journal of Microbiology and Biotechnology
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• 제4권4호
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• pp.333-337
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• 1994

In order to develop the whey beverage, we examined the optimum conditions for alcohol fermentation by Kluyveromyces tragilis ATCC 46537. The optimum conditions for alcohol production by K. fragilis ATCC 46537 were as follows; pH 4.5, $30^{\cir}C$, with a supplement of 50 g/l of lactose. To develop a continuous production of alcohol from whey, we compared batch fermentation with continuous iermentation in conjunction with UF system. Batch fermentation produced 11.0 g/l of alcohol, whereas pseudocontinuous and continuous fermentation with UF system produced 8.5 g/l of alcohol. To increase the alcohol production, we added 50 g/l of lactose to both fermentations. Batch fermentation with lactose supplement produced 15.7 g/l of alcohol and continuous fermentation with lactose supplement in conjunction with UF system produced 15.0 g/l of alcohol. These results clearly demonstrate that the UF system can be used to increase the alcohol production from whey, supplemented with exogenous lactose.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.319-323
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• 2005

This study is concerned with development of efficient culture methods for lactic acid fermentation of Lactobacillus sp. RKY2. The cell-recycle repeated batch fermentation using cheese whey and corn steep liquor as raw materials was tried in order to further enhance the productivity of lactic acid. In addition, fermentation efficiencies could be considerably enhanced by cell-recycle continuous culture. Through the cell-recycle repeated batch fermentation, lactic acid productivity was maximized to 6.34 $g/L{\cdot}h,$ which corresponded to 6.2 times higher value than that of the batch fermentation. During the cell-recycle continuous fermentation, the last dry cell weight at the end of fermentation could be increased to 25.3 g/L.