• 상하수도학회지
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• 제23권2호
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• pp.175-180
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• 2009

This study was conducted to improve biological degradation efficiency of toluene as a model volatile organic compound (VOC) using yeast Candida tropicalis and to suggest an effective method for bioreactor operation. The yeast strain was immobilized with polyethylene glycol (PEG), alginate, and powdered activated carbon (PAC). The yeast-immobilized polymer media were used as fluidized materials in an airlift bioreactor. Polymer media without PAC were also made and operated in another airlift bioreactor. The two bioreactors showed toluene removal efficiencies ranging 80-96% at loading rates of $10-35 g/m^3-hr$, and the bioreactor containing the polymer media with PAC achieved higher removal efficiency. Protein contents in the liquid phase showed that the bioreactor using the yeast-immobilized polymer media with PAC had a higher rate of microbial growth initially than that without PAC. In addition, the microbial growth rate inside of the polymer media with PAC was five times higher than that without PAC. Consequently, the polymer media containing the yeast strain and PAC could enhance removal efficiencies for VOCs, and the immobilization method improve microbial activity and stability for a long-term operation of biological systems.

• KSBB Journal
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• 제14권5호
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• pp.534-538
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• 1999

식물세포배양을 위한 bioreactor의 운전조건 최적화를 위해 Nicotiana tabacum 현탁세포를 model system으로 bioreator의 종류, 교반기의 형태, 그리고 통기량에 따른 세포생장을 관찰하였다. Bioreactor로는 stirred tank bioreactor과 airlift bioreactor를 사용하였으며 두가지 배양기 모두 flask에서의 생장보다 낮은 생장을 보였으며 stirred tank bioreactor보다는 airlift bioreator에서 높은 세포농도를 얻을 수 있었다. 교반기의 종류에 따른 세포의 생장은 큰 차이가 없었으나 hollowed paddle impeller를 사용하였을 경우에는 배양기간 동안 세포의 크기가 작게 유지되었다. 통기량을 0.30 vvm으로 유지하는 경우에 가장 좋은 세포생장을 관찰할 수 있었으며 1.0 vvm이상의 통기량에서는 과도한 foam의 형성과 세포의 갈색화 현상을 보이며 세포의 생장도 저해되었다. 또한 통기량이 증가할수록 세포크기지수가 감소하는 결과를 보였다.

• 대한환경공학회지
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• 제31권8호
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• pp.603-610
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• 2009

본 연구는 휘발성유기화합물질의 분해능력을 가진 yeast인 Candida tropicalis를 이용하여, 대표적인 휘발성 유기화합물질인 톨루엔과 MEK의 제거효율을 향상시키기 위하여 수행되었다. 반응기는 가스상으로 유입되는 톨루엔과 MEK의 물질전달 능력을 향상시키기 위하여 airlift loop 형태로 선택하였고, yeast 미생물의 효과적인 포괄고정화를 위해 분말활성탄(PAC)과 알지네이트(Alginate), PEG로 고분자 담체를 형성하였다. Airlift loop bioreactor의 물질전달성능을 평가하기 위한 실험을 수행하였으며, 기체체류시간 15초에서 담체를 첨가하지 않은 액상의 톨루엔 물질전달계수($K_La$) 값이 1.29 $min^{-1}$이었으나, 고분자 담체를 첨가한 경우 톨루엔의 $K_La$는 4.07 $min^{-1}$로 증가하였다. 따라서 고분자담체를 적용하는 것이 기상으로 유입되는 휘발성유기화합물의 물질전달을 향상시키는 것으로 확인되었다. 이러한 airlift loop bioreactor와 yeast 포괄고정 담체를 적용하여 체류시간을 60초, 30초, 15초에서 유입부하에 변화를 주며 실험을 진행한 결과, 톨루엔 5, 10, 19, 37 g/$m^3$/hr, MEK 4.5, 8.9, 17.8, 35.1 g/$m^3$/hr의 유입부하 변화에도 전체 80% 이상의 안정적인 처리효율을 나타내었다. 또한 airlift loop bioreactor의 분해능을 확인하기 위하여 유입부하를 단기간 변화시켜 주며 실험한 결과, 톨루엔과 MEK의 최대분해능은 각각 70.4 g/$m^3$/hr, 56.4 g/$m^3$/hr로 확인되었다.

• KSBB Journal
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• 제14권4호
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• pp.440-444
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• 1999

S. clavulirerus ATCC 27064 균주는 약 200 mg/L의 clavulanic acid를 생산하였지만, 이 균주를 NTG에 의해 돌연변이 시킴으로써 얻어진 S. clavuligerus KK를 같은 배양조건에서 약 5배 많은 1150 mg/L의 clavulanic acid를 생산하였다. 무기염이 첨가되지 않은 clavulanic acid의 기본 생산 배지에서는 clavulanic acid의 생산량은 1150 mg/L였으나 다양한 무기염 중에서 MgSO$_4$가 첨가된 배지에서는 약 2000 mg/L나 생산되었다. 따라서 기본 배지조성인 1%(v/v) glycerol, 1.5%(w/v) soybean flour, 0.1%(w/v) $KH_2PO_4$, 0.2%(v/v) soybean oil에 0.4%(w/v) MgSO$_4$를 첨가함으로써 clavulanic acid의 생산을 높일 수 있었다.Airlift 와 bubble column 및 교반식 생물반응기에서 회분식 배양을 했을 경우 clavulanic acid의 생산은 airlift 생물 반응기에서는 1100 ng/L, bubble column 생물 반응기에서는 1450 mg/L, 교반식 생물 반응기에서는 1500 mg/L가 생산되어, 교반식 반응기가 적절하다고 생각되며 이는 배양액이 시간이 지날수록 점도가 높아지기 때문에 임펠러에 의한 교반 효과가 있는 교반식 반응기에서 물질전달이 가장 용이하기 때문인 것으로 보인다. 특히 교반식 생물 반응기에서 용존산소농도에 따라 교반속도를 조절하여 회분식 배양을 했을 경우가 수율이 0.18, 생산성은 250mg/Lㆍday로 가장 우수하게 나타났다.

• 한국환경과학회지
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• 제8권4호
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• pp.479-483
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• 1999

Nitrifier consortium immobilized in polyvinyl alcohol was used for the removal of ammonia nitrogen from synthetic aquaculture water in the airlift bioreactor. At the aeration rate fo 0.15 vvm and bead packing volume fraction of 20%, airlift bioreactor was operated effectively for a removal of ammonia nitrogen and for a stability of operation. Ammonia nitrogen removal rate by airlift bioreactor was continuously increased with decreasing hydraulic residence time. At the HRT(hydraulic residence time) of 0.3 hour, ammonia nitrogen removal rate was 84.3 g/$m^3$.d and the highest ammonia nitrogen removal rate was 130.8 g/$m^3$.d when HRT was 0.1 hour.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권1호
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• pp.72-74
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• 2001

Transgenic Nicotiana tabacum cells were cultivated for the production of murine granulocyte macrophage-colony stimulating factor (mGM-CSF) in both a stirred tank bioreactor and an airlift bioreactor with draft tube. Cell growth and mGM-CSF production in the airlift bioreactor were found to be better than those achieved in the stirred tank bioreactor. In the airlift bioreactor, 9.0g/L of cells and 2.2ng/mL of mGM-CSF were obtained (11.0g/L and 2.4ng/mL, respectively in shake flasks). Although the lag period was prolonged and mGM-CSF production was lowered by 33% in the stirred thank bioreactor as compared to the control culture, the maximum cell density was increased up to 12.0g/L due to better mixing by agitation at the higher cell density.

• 한국수산과학회지
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• 제36권6호
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• pp.661-668
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• 2003

Performance of an airlift bioreactor (ABR) containing the immobilized microorganisms was evaluated in an integrated pilot scale recirculating aquaculture system stocked with Nile tilapia (Oreochromis niloticus) at an initial rearing density of $5\%$ and compared to a rotating biological contactor (RBC) for 40 days. The TAN concentration of rearing tank for ABR and RBC were maintained at $0.4\;g/m^3$ and $0.5\;g/m^3,$ respectively, The nitrite nitrogen was completely removed by the ABR. The ABR's aeration was more stable than the RBC's. On the whole, the feasibility of ABR as an aquacultural water treatment unit was recognized.

• Plant Resources
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• 제3권3호
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• pp.219-222
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• 2000

For the purpose of establishing an efficient propagation through airlift bioreactor system of Zingiber of officinale Rosc. Korean native Seosanjong, the effect of different factors and bioreactor on cultured plantlets were investigated. The highest number of plantlets, fresh weight per plant was obtained from explants when cultured in MS liquid medium including 0.3 mg/L NAA and 2.0 mg/L kinetin for 40 days. A 10 L bottle type bubble bioreactor, compared with 250 mL Erlenmeyer flask, was more efficient, producing 4.7 plantlets or from 1.5 to 1.6 times more than did the Erlenmeyer flask. The results demonstrate the rapid mass propagation of airlift bioreactor to produce normal ginger.

• Journal of Plant Biotechnology
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• 제3권1호
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• pp.1-5
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• 2001

Traditional culture technology of medicinal plants mainly depends on the field culture, which has many problems. With progress of modern culture technology, it has become possible to produce valuable secondary metabolites from medicinal plants. In this paper, we discuss about the pigment and saikosaponin production from too medicinal plants, Carthamus tinctorius and Bupleurum falcatum, through bioreactor culture system. A two-stage bioreactor culture system was established for the production of yellow and red pigments and saikosaponins by cell suspension cultures of Carthamus tinctorius and Bupleurum falcatum. In Carthamus tinctorius, balloon type airlift bioreactors and column type airlift bioreactors were employed for the tell culture and for the pigment production, respectively. The greatest pigment production was obtained on White medium supplemented with 4 mg/L kinetin, high levels of sucrose concentration and photosynthetic photon flux. In Bupleurum falcatum, adventitious roots were cultured in balloon type airlift bioreactors and the root growth was greatest on SH medium containing 5 mg/L IBA and 0.2 mg/L kinetin. HPLC analysis showed that the contents of main active saikosaponins a, c, and d in adventitious roots were almost the same as those in field cultured root.

• Journal of Microbiology and Biotechnology
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• 제17권7호
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• pp.1071-1078
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• 2007

Using a 50-1 airlift bioreactor, for the effective production of tylosin from Streptomyces fradiae TM-224 using raw cornmeal as the energy source, various environmental factors were studied in flask cultures. The maximum tylosin concentration was obtained at $32^{\circ}C$ and pH between 7.0 and 7.5. When seed was inoculated after 24 h of culture, the maximum tylosin concentration, 5.7 g/l, was obtained after 4 days of culture. Various concentrations of raw cornmeal were tested to investigate the optimum initial concentration for the tylosin production. An initial raw cornmeal concentration of 80 g/l gave the highest tylosin concentration, 5.8 g/l, after 5 days of culture. Of the various nitrogen sources, soybean meal and fish meal were found to be the most effective for the production of tylosin. In particular, with the optimal mixing ratio, 12 g/l of soybean meal to 14 g/l of fish meal, 7.2 g/l of tylosin was obtained after 5 days of culture. To compare raw cornmeal and glucose for the production of tylosin in the 50-1 airlift bioreactor for 10 days, fed-batch cultures were carried out under the optimum culture conditions. When raw com meal was used as the energy source, the tylosin production increased with increasing culture time. The maximum tylosin concentration after 10 days of culture was 13.5 g/l, with a product yield from raw cornmeal of 0.123 g/g of consumed carbon source, which was about 7.2 times higher than that obtained when glucose was used as the carbon source.