• KSBB Journal
• /
• v.9 no.4
• /
• pp.347-364
• /
• 1994

Airlift bioreactors are extensively used in the fields of aerobic fermentation, animal and plant cell cultures. This review article evaluates the present research activities in the field of airlift bioreactors. The published research works on the design parameters such as types, location and properties of gas sparser, hydrodynamic properties such as phase holdups mixing, liquid circulation rate, mass and heat transfer rates are summarized. Also, recommendations are presented for designing airlift bioreactors.

• KSBB Journal
• /
• v.14 no.4
• /
• pp.440-444
• /
• 1999

For the effecient production of clavulanic acid., a mutant strain Streptomyces clavuligerus KK was selected from Streptomyces clavuligerus ATCC 27064 through mutation with NTG. S. clavuligerus ATCC 27064 produced about 200 mg/L of calvulanic acid when the medium was composed of 1%(W/V) glycerol, 1.5%(W/V) soybean flour, 0.1%(W/V) $KH_2PO_4$, 0.2%(V/V) soybean oil. A selected mutant, S. clavuligerus KK, produced about 1150 mg/L of clavulanic acid in the same medium. After the addition of $MgSO_4$ to the basal medium, S. clavuligerus KK produced about 1550 mg/L of clavulanic acid, with shows about 1.3 times higher than that produced in the basal medium. In order to select the proper bioreactor for the production of clavulanic acid, a batch culture was performed in an airlift, a bubble column and an stirred tank bioreactors. In an airlift bioreactor, about 1350 mg/L of clavulanic acid was produced, in a bubble column bioreactor, about 1550 mg/L, in a stirred tank bioreactor, about 2200 mg/L, respectively. The production of clavulanic acid in stirred tank bioreactor was about 50% higer than that by an airlift and a bubble column bioreactors. According to this result, the stirred tank bioreactor was selected as a proper bioreactor.

• Korean Journal of Plant Tissue Culture
• /
• v.28 no.3
• /
• pp.135-140
• /
• 2001

A series of studies were carried out to establish micropropagation system, using airlift bioreactors (ebb $\varepsilon$ flood type, 5 L), of Lilium oriental hybrid 'Casa Blanca'. The bulblets with swollen basal plate were formed from bulb scales, then proliferated to bulblet clusters with swollen basal plate. Finally normal bulblets were formed from the sections. Bulblet formation and proliferation with swollen basal plate were not accomplished entirely in liquid culture of 5 L airlift bioreactors, but leafy bulb scales grew vigorously. Bulblet clusters with swollen basal plate were proliferated by periodic immersion culture. Bulblet proliferation was not affected by light, but scale leaves grew under light. MS medium containing 2.0 mg/L benzyl adenine (BA) and 0.3 mg/L indole acetic acid (IAA) was favorable to the bulblet proliferation with swollen basal plate. In liquid culture of 5 L bioreactors, bulblets from bulblet sections with swollen basal plate grew vigorously on MS medium with 70 g/L sucrose. It was effective for bulblet growth to replace the new medium after 8 weeks in culture during 16 weeks of cultural period. 15 g injection of bulblet sections as a cultural material was suitable for bulblet growth in 5 L bioreactors.

• Journal of Korean Society of Water and Wastewater
• /
• v.23 no.2
• /
• pp.175-180
• /
• 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.

• The Microorganisms and Industry
• /
• v.20 no.2
• /
• pp.20-25
• /
• 1994

많은 산업용 ALB가 여러 발효공정에서 성공적으로 사용되고 있음에도 불구하고, 반응기의 설계를 위해 필요한 기본적인 지식들을 제공하는 자료는 그리 많지 않다. 본 총설에서는 ALB의 기본개념을 소개하고, ALB의 설계를 위해 이용가능한 기본적인 정보를 제시하고자 한다.

• 한국생물공학회:학술대회논문집
• /
• 2000.11a
• /
• pp.457-460
• /
• 2000

A biofilm airlift reactor filled with biomass-covered carriers (sand) were used to remove ammonium by selective nitrification (ammonium to nitrite). The effects of experimental conditions (ammonium load, pH, dissolved oxygen) on nitrification and nitrite accumulation were investigated. The reactor showed more than 90% nitrification efficiencies at 2.5 kg $NH_4\;^+-N/m^3/d$ and $NO_2\;^--N$ could be accumulated between 75% and 90% in the effluent. It is likely that nitratation (nitrite oxidizer) was inhibited by low dissolved oxygen concentration while nitritation (ammonium oxidizer) was kept stable.

• KSBB Journal
• /
• v.11 no.2
• /
• pp.238-245
• /
• 1996

Microbial desulfurization characterlstics of a bituminous coal have been determined by using Thiobacillus ferrooxidans. The effects of process variables (such as coal pulp density, particle size and addition of surfactants) on pyrite removal have been investigated in both shake and airlift-bioreactor culture experiments. In shake experiments, pyrite could be removed over 78% for pulp densifies below 20% (w/v) and removed below 40% for pulp densities over 30% (w/v) in 8 days. Pyrite removal decreased with increasing pulp densities, and it also decreased sharply with increasing particle sizes. In airlift bioreactor experiments, pyrite at 50% (w/v) pulp density could be removed about 50%. Its value is much higher than 15% at the same pulp density in a shake experiment. With addition of surfactants, pyrite removal was enhanced in shake experiments significantly, whereas it was slightly decreased in an airlift bioreactor experiment.

• KSBB Journal
• /
• v.16 no.6
• /
• pp.573-578
• /
• 2001

The effects of organic supplement (acetate) and dissolved oxygen concentration on the nitrification rate of wastewater were investigated in the 27.7 L pilot-scale airlift biofilm reactor with the granular activated carbon media of 0.613 mm diameter. The ammonium oxidation rate increased stepwise up to 5 kg N/㎥$.$d at the riser air velocity of 0.063 m/s, when the air velocity and the ammonium loading rate were raised alternately. The nitrite build-up was observed during the early stage of the biofilm formation, which disappeared after the reactor operation of 128 days. As increasing the organic loading rate, the organic oxidation rate increased up to 25.0 kg COD/㎥$.$d with the removal efficiency of 94% but the oxidation rates of ammonium and nitrite decreased. The oxidation rates of ammonium and nitrite increased with the dissolved oxygen concentrations. When the pure oxygen was sparged, the ammonium oxidation rate was almost five times higher than that with air at the same velocity.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.36 no.6
• /
• pp.661-668
• /
• 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.

• Korean Journal of Medicinal Crop Science
• /
• v.12 no.6
• /
• pp.478-482
• /
• 2004

Suspension culture of Schisandra chinensis for production of gomisin J was perfomed in bioreactor. The inoculum size and initial sucrose concentration had significant effect on the cell growth and gomisin J accumulation. The maximum dry cell weight $(DCW;\;43.5\;g/{\ell})$ and gomisin J content $(0.71\;{\times}\;10^{-3}\;{\mu}g/g\;DCW)$ were obtained at inoculum size of 100 g fresh cell weight (FCW) per liter and MB5 medium containing 6% sucrose after 8 weeks of culture. The effect of oxygen supply on the cell growth and gomisin J accumulation was also investigated in an airlift-type bioreactor. The optimal cell growth and gomisin J content was obtained under 0.5 vvm. The productivity of gomisin J was 0.7 fold in bioreactor culture lower than that obtained in a flask cultivation.