• KSBB Journal
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• 제24권4호
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• pp.377-382
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• 2009

본 연구는 다양한 조건에서의 실험을 위한 C. minutissima의 500 mL flask의 종 배양을 통해 고농도의 균주 획득 후, 가장 효율적인 배양 방식을 보인 fed-batch를 통한 autotrophic, heterotrophic, mixotrophic 조건하에서 바이오디젤용 지질 생산의 최적 배양 조건을 찾아야했다. 먼저, fed-batch의 Heterotrophic 배양 시 유기 탄소 원으로 glucose의 가장 효율적인 안정한 초기농도가 10 g/L임을 확인했다. 이 후, 20 L 배양기를 이용한 batch, fed-batch의 heterotrophic 배양에서 fed-batch배양의 경우 지질 생성양이 1.62배 정도 더 높았으며, 최대 균체량 역시 4 (g-dry wt./L)정도 높으며, 또한 디젤용 지질로 적합한 $C_{18}$의 조성 역시 49%이상 차지하여, 옥외 대량 배양 시 유기탄소 원으로 적절한 glucose의 이용을 통한 효율적인 배양방법임을 알 수 있다. 이 결과를 바탕으로, glucose를 포함한 배지를 0.5 L/day로 공급하여 유가 식 배양을 각 배양 조건에 따라 비교 실시했다. 그 결과 mixotrophic의 경우 다른 배양 조건에 비해 각각 24 (g-dry wt./L)의 최대 군체 농도와 함께 43 (%, w/w)의 높은 지질 생성량을 보였다. 또한 생성되는 지질의 조성이 균체 당 바이오 디젤용 양질의 지질 생성이 가능하였다. 또한 fed-batch 배양 이후 0.047 (% lipid/g-dry wt./day)의 비 생산 속도를 유지하며, 일정 균체 농도를 유지하는 경우 지속적인 지질 생성이 가능함을 보여주었다. 이러한 세 가지 배양 조건하에서 지질 추출을 통한 지방산 조성을 살펴본 결과 mixotrophic 배양 하에 디젤용으로 잘 알려진 $C_{17}$, $C_{18}$의 지방산 조성은 각각 18%와 49%의 생성을 보여주었다. 이 결과들을 바탕으로 이 균주를 이용해 옥외 배양이나 배양 조에서 대량 배양이 가능함을 확인했으며, 특히, 옥외배양을 위한 혼합영양 배양조건하에 배양 공정의 scale-up에 대한 추가적인 연구를 통해 C. minutissima 미세조류로부터 바이오 디젤의 보다 경제적 생산이 가능하도록 하고자 한다.

• Journal of Microbiology and Biotechnology
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• 제7권6호
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• pp.417-422
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• 1997

Recombinant Bacillus subtilis LKS88[pASA240] containing the amylase gene from Streptomyces albus KSM-35 was exploited in fed-batch cultivation for mass production of maltotetraose-producing amylase. The effects of dissolved oxygen, additional organic nutrients (peptone and yeast extract) and mixed carbon sources (glucose plus soluble starch) on amylase production were examined in fed-batch operations in an effort to determine the optimum conditions for a maximum amylase productivity. Under the optimum conditions, maximum amylase activity was about 4.2 times higher than that obtained in batch cultivations, indicating that mass production of maltotetraose-producing amylase could be accomplished in fed-batch cultivation of the recombinant B. subtilis strain.

• Journal of Microbiology and Biotechnology
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• 제11권5호
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• pp.739-748
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• 2001

A self-organizing fuzzy logic controller using a genetic algorithm is described, which controlled the glucose concentration for the enhancement of flavonoid production in a fed-batch cultivation of Scutellaria baicalensis G. plant cells. The substrate feeding strategy in a fed-batch culture was to increase the flavonoid production by using the proposed kinetic model. For the two-stage culture, the substrate feeding strategy consisted of a first period with 28 g/I of glucose to promote cell growth, followed by a second period with 5 g/I of glucose to promote flavonoid production. A simple fuzzy logic controller and the self-organizing fuzzy logic controller using a genetic algorithm was constructed to control the glucose concentration in a fed-batch culture. The designed fuzzy logic controllers were applied to maintain the glucose concentration at given set-points of the two-stage culture in fed-batch cultivation. The experimental results showed that the self-organizing fuzzy logic controller improved the controller\`s performance, compared with that of the simple fuzzy logic controller. The specific production yield and productivity of flavonoids in the two-stage culture were higher than those in the batch culture.

• KSBB Journal
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• 제6권1호
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• pp.35-43
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• 1991

The production of poly-$\beta$-hydroxybutyrate(PHB) from methanol by batch and fed-batch cultivations of Methylobacterium sp. GL-10 was studied. PHB accumulation was stimulated by the nutrients deficiency including, NH4+, SO42-, and K+. The nitrogen deficiency was the most critical factor for PHB accumulation. In batch cultivation, the maximum cell concentration and PHB content were 1.86g/l and 0.62g/l, respectively, with 1.0%(v/v) of methanol and 0.5g/1 of ammonium sulfate. The mass doubling time of Methylobacterum sp. GL-10 was in the range of 4-5 hrs. The cell growth and PHB accumulation were severely inhibited at the methanol concentration over than 2% (v/v). To overcome methanol Inhibition, constant feeding and intermittent feedillg fed-batch cultivations were adopted, using C/N molar ratio as a control factor. In constant feeding fed-batch process, cell concentration was increased up to 2.67g/1, and PHB yield was enhanced from 0.33 of batch culture to 0.53. The relatively low cell concentration was caused by methanol accumulated in culture broth at late growth phase. To prevent methanol accumulation and to maximize PHB production, DO-state intermittent fed-batch cultivation was attempted. The cell and PHB concentration was reached up to 4.55g/1 and 1.80g/1, respectively. It was possible to maintain methanol concentration low and also to feed nutrient of desired C/N molar ratio.

• 한국미생물·생명공학회지
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• 제19권5호
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• pp.504-508
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• 1991

유전자 재조합된 동물 세포의 유가 배양시 $1.85\times 10^{-10}$(mmole/cell/h)의 비 glucose 소비속도와 $4.7\times 10^{-7}(\mu g/ceil/h)$의 erythropoetin (EPO)비 생산속도를 유지할 수 있었다. 또한 이같은 배양에서 회분 및 연속배양에서 보다 높은 세포수를 얻었으며 전 배양이 유사 안정상태에 도달하는 배양 후기에는 glutamolysis가 생육 공정에 매우 중요한 역활을 하고 있음이 확이됐다. 유가 배양시 13(mmloe/l)의 glucose 농도에서 생육 제한 현상이 일어났으며, 이같은 농도에 도달할 때까지는 glucose의 농도가 증가함에 따라 배양시간의 경과와 함께 EPO 생산성이 증가했다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.390-393
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• 2001

The optimal temperature, pH and aeration rate for spore production by Bacillus polyfermenticus SCD in 500 ml shake flask and 5-1 jar fermenter were found to be $32^{\circ}C$, 7.0 and 1.0 vvm. respectively. When batch culture processes was performed under optimized culture conditions. viable cells were $3.3{\times}10^{10}$ CFU/ml and spore cells were $3.3{\times}10^{10}$ CFU/ml. Fed-batch culture processes were also examined with regard to higer maximum viable cell and spore production. The highe viable cells and spores were obtained in 5-1 jar fermenter at 72 h cultivation time by strategy in an intermediate feeding mode with 60% glucose solution 150 ml and 5% soybean flour solution 150 ml fed to the fermenter twice, and the productivity of spore cells was significantly increased. Finally. volumetric productivity of spore cells on fed-batch culture indicated $9.9{\times}10^8$ CFU/ml/h, which was approximately 2 times higher than batch culture. Thus, fed-batch culture show a promise as an industrial production method.

• Journal of Microbiology and Biotechnology
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• 제1권2호
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• pp.111-115
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• 1991

The green alga, Dunaliella salina under fed-batch cultivation produced 51.12 mg of hydrocarbon per liter with maintaining 0.313 (g dry wt/l). About 20% of hydrocarbon production yield based on dry biomass was obtained from both batch and fed-batch processes. Optimum culture conditions of light intensity, pH and salt concentration were obtained as 0.0080 (kJ/$cm^2$/h), 8.0 and 1.4 (g of NaCl/l), respectively by response surface analysis. The production of hydrocarbons in D. salina was closely correlated to cell growth. Fed-batch cultivation produced more hydrocarbons and maintained better cell growth than a batch process.

• KSBB Journal
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• 제14권3호
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• pp.365-370
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• 1999

To optimize the culture conditions for Beauveria bassiana 726, the effects of culture medium, pH, and temperature on mycelium and spore production were investigated. The optimum temperature and pH for the cultivation of B. bassiana 726 were 28 $^{\circ}C$ and 5.0, respectively. The optimized medium was composed of 1.0~2.0% total sugar from molasses, 0.5% corn steep liquor and 0.05% KH$_2$PO$_4$. In the cultivation of B. bassiana 726 with the optimum medium, the specific growth rate and substrate utilization were well-fitted with the proposed kinetic model in the shake flask and stirred tank reactor. When the fed-batch cultivation using carbon suorce, nitrogen source, and mineral salt as a feeding medium was compared with batch cultivation in stirred tank reactor, mycelium (12.7 g/L) and spore production (5.4$\times$$10^8/mL$) were enhanced up to 110% and 85%, respectively.

• Journal of Microbiology and Biotechnology
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• 제6권4호
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• pp.295-298
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• 1996

Under glutamine-limited condition, $2\times10^6$ (viable cells/ml) of maximum cell density and 13.5 ($\mu g$/ml) of tissue-type Plasminogen Activators (tPA) production were maintained by spike feeding fresh medium in fed-batch cultivation of human recombinant melanoma cells. It showed that tPA production was much seriously affected than cell growth according to initial glutamine concentrations. Above 3.4 (mmol/I) of glutamine concentration both cell growth and tPA production were not much affected by increasing initial glutamine concentration. Glutamine depleted situation was occurred at latter periods of batch and fed-batch cultivations below 5.4 (mmole/I) of initial glutamine concentration. It also showed that maximum glutamine consumption and ammonia evolution rates were closely related to initial glutamine concentrations. Maximum specific tPA production rate was estimated as $8.1\times19^{-6}$ ($\mu g$/cells/h) at 3.4(mmol/I) of glutamine concentration, which is higher than that from other batch and fed-batch processes.

• 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.