• Clean Technology
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• v.16 no.1
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• pp.39-45
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• 2010

In this paper, 4 bundle modules of PVDF hollow fiber membrane from Woori Tech company (Korea) were manufactured in a treatment capacity of 10 ton/day. A membrane bioreactor (MBR) pilot plant was installed at Sooyoung Wastewater Treatment Plant in Busan. An alternating aeration process was selected to avoid the concentration profile of suspended solid (SS) in the MBR. For stable operation, raw wastewater with mixed liquor suspended solid (MLSS) of about 1,000 ppm, which was in-flowed from the aeration tank of the wastewater treatment plant, was fed and filtered through the pilot plant. Subsequently the pilot plant were washed three times with washing water: once with ethanol solution, once with a solution of 5% NaOCl, and finally with washing water. After the chemical washing, the remaining water in the MBR was fed into the pilot plant. As a result, the SS removal efficiency was found to be more than 99.9%. The amount of filtrate with the aeration tank influent decreased by 16%, compared with that from the initial conditions, giving rise to 30% increase in the suction pressure. These results were used to set up continuous operation conditions. The results from the continuous operation with influent MLSS of 1,900 mg/L showed that the SS removal efficiency was about 99.99% and that the amount of filtrate and the suction pressure were $42{\sim}52L/m^2$ and 16~20 cmHg, respectively, indicating stable operation of the pilot plant. However, for the reuse of wastewater, methods need to be sought to avoid growth of algae which affects the SS removal efficiency at inlet and outlet of the permeate tank.

• Journal of Microbiology and Biotechnology
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• v.10 no.5
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• pp.728-732
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• 2000

Propagation of Anagrapha falcifera nuclear polyhedrosis virus(AfNPV) was investigated using well-plates and split-flow air-lift bioreactors. In well-plate experiments, the effects of pH, cell density at a point of infection, serum concentration, DEAE-dextran, and lipid on virus propagation were all closely examined. The AfNPV titer in well-plates was optimal at pH 6.8 and $3{\times}10^6$ cells/$cm^2$. The virus titer was not dramatically affected when the fetal bovine serum concentration was reduced from 10% to 5%. The addition of cholesterol at AfNPV infection of Sf21 cells enhanced the virus titer, whereas the addition of DEAE-dextran did not improve the titer. The AfNPV titer ($3.8{\times}10^7$ $TCID_{50}/ml$) at optimized conditions for well-plate experiments was 2.5-fold higher than for the control. In bioreactor experiments, the AfNPV titer showed its maximum level at air flow rates of 20-40 ml/min. In a split-flow air-lift bioreactor, AfNPV titer ($2.3{\times}10^7\;TCID_{50}/ml$) was 1.5-fold higher than the control when the culture was at pH 6.8 and supplemented with 0.34 mM cholesterol.

• Journal of Plant Biotechnology
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• v.35 no.2
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• pp.127-132
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• 2008

In bioreactor cultures of plants, inoculum density is an important factor affecting growth and proliferation of the plantlets. To maximize shoot growth and proliferation of grape rootstock '5BB' in bioreactors, inoculum density varied at 15, 30, 45 and 60 single nodes in a 3-liter scale balloon type bioreactor, respectively and cultured for 40 days. Results suggested that the growth and the photosynthesis of the plantlet were greatly affected by inoculum density in the bioreactor. The inoculum density of 45 nodes resulted in the greatest growth (910.4 mg/shoot FW, 764.4 mg/root FW) followed by 30 nodes. $CO_2$ assimilation rate, stomatal conductance, transpiration rate of the plantlet were also highest at the inoculum density of 45 nodes. Significant reduces in shoot and root growth (426.5 mg/shoot FW, 248.4 mg/root FW) were observed at the inoculum density of 60 nodes. When the inoculum density decreased by 15 nodes, plantlets were malformed due to hyperhydricity, resulting in the highest transpiration rate and the lowest $CO_2$ assimilation rate. The plantlets stressed by the inoculum density at 15 nodes and 60 nodes showed larger number and irregular shape of stomata compared to the plantlets inoculated with 45 nodes.

• Journal of Life Science
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• v.12 no.5
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• pp.577-583
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• 2002

The growth kinetics and the production of $\beta$-glucuronidase from transgenic tobacco's suspension culture was investigated in the flask culture and a 2.5 L bubble column reactor. The growth of bubble column reactor was similar to that of flask culture. However, in the bubble column reactor, the production of $\beta$ -glucuronidase reached 2850 U/mg (85-fold higher than that of flask culture). In both case, the production level of $\beta$ -glucuronidase was fluctuated, which was resulted from periodical degradation of the protein. Sucrose is important component in plant culture medium. Twice addition of sucrose in bubble column reactor could not improve cell growth, since other components in a medium were already depleted. However, the addition of sugar decreased cell size, which facilitated the operation of bioreactor. The production of $\beta$ -glucuronidase was continuously increased, however final concentration of $\beta$ -glucuronidase was similar to that without sucrose addition.

• Korean Journal of Medicinal Crop Science
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• v.8 no.1
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• pp.9-13
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• 2000

To determine the proper carbon and nitrogen sources and their proper levels for mass micro propagation of Scrophularia buergeriana Miquel, tonic and curing cough experiment were applied and a method for mass cultivation by using bioreactors (2.5 L) was expinined. Proper ratio of $NH_4NO_3\;:\;$KNO_3$ was 413 mg/L : 1900 mg/L for multiple shoot production. Sucrose was more effective than glucose or fractose as carbon source and 3% concentration was good for shoot formation. Total nitrogen was not detected after six weeks both in 500 ml flask and bioreactor culture. Sucrose was decreased sharply after two weeks and there was no sucrose left after three weeks both in 500 ml flask and bioreactor culture. The stirrer in bioreactor caused shear stress to shoots severely. The sphere type bioreactor was better than the cylinder type and removal of inner loop in sphere type was more effective to avoid shear stress.

• Korean Journal of Medicinal Crop Science
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• v.8 no.2
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• pp.117-122
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• 2000

This study was carried out to know the factors affecting on shoot formation and rooting for stable and routine production of plantlets in bioreactor culture of Scrophularia buergeriana. Multiple shoots were formed effectively when explants were transplanted on the MS media with decreased concentration of $NH_4NO_3$ as 413mg/ l . Three hundred stem explants (0.8-1.0cm) was appeared as proper inoculation size in bioreactor culture. IBA (0.05mg/L) was more effective for rooting of the shoots in liquid as well as solid media. Six weeks long culture of explants in bioreactor gave better shoot shape for rooting on solid half-strength MS media.

• Journal of Plant Biotechnology
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• v.31 no.4
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• pp.295-300
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• 2004

This article was conducted to induce the transgenic hairy roots and determine the effect of culture conditions on optimum growth of hairy roots by Agrobacterium rhizogenes strain, 15834 in Lycium chinense Miller. Hairy roots of L. chinense Miller. were induced from leaf segments by co-cultivation with A. rhizogenes. When the hairy roots were cultured in various MS medium strength and sucrose concentrations, the highest growth of hairy roots was observed in half-strength MS media supplemented with 3% sucrose, respectively. In air lift bioreactor cultures, the liquid medium contained with 1/2 MS and 3% sucrose was also the best for optimum growth of hairy roots.

• Korean Journal of Medicinal Crop Science
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• v.9 no.1
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• pp.62-67
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• 2001

This study was carried out to investigate the optimum composition and concentration of medium for the acclimation of the shoots derived from bioreactor culture of Scrophularia buergeriana. Rooting and growth of the shoots cultured in bioreactor for 4 weeks were better on liquid full strength MS medium while one-tenth of MS medium was good for rooting and growth of the shoots cultured in bioreactor for 6 weeks. Leaf expansion was more effective in the shoots cultured for 6 weeks on solid MS medium than in those cultured for 4 weeks. No leaf expanded in liquid medium. Vitrification rate was higher in full strength solid MS medium than in half strength MS medium. It is concluded that acclimation of the shoots is more effective on the half strength solid MS medium containing 1.2% agar.

• Journal of Microbiology and Biotechnology
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• v.26 no.5
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• pp.928-937
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• 2016

S-Nitrosoglutathione reductase (GSNOR) metabolizes S-nitrosoglutathione (GSNO) and has been shown to play important roles in regulating cellular signaling and formulating host defense by modulating intracellular nitric oxide levels. The enzyme has been found in bacterial, yeast, mushroom, plant, and mammalian cells. However, to date, there is still no evidence of its occurrence in filamentous fungi. In this study, we cloned and investigated a GSNOR-like enzyme from the filamentous fungus Aspergillus nidulans. The enzyme occurred in native form as a homodimer and exhibited low thermal stability. GSNO was an ideal substrate for the enzyme. The apparent K_m and k_cat values were 0.55 mM and 34,100 min^-1, respectively. Substrate binding sites and catalytic center amino acid residues based on those from known GSNORs were conserved in this enzyme, and the corresponding roles were verified using site-directed mutagenesis. Therefore, we demonstrated the presence of GSNOR in a filamentous fungus for the first time.

• Korean Journal of Medicinal Crop Science
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• v.8 no.2
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• pp.123-128
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• 2000

This study was carried out to determine factors affecting on the mass propagation of Rehmannia glutinosa seedlings in bioreactor culture. Air-lift type bioreactor was more compatible to shoot formation than stirrer type. Fifty grams(90 stem explants) of inoculum in 1.5L medium was placed into 2.5L bioreactor with aeration rate of 0.5 v.v.m., which was proper for effective shoot formation. Adding MES as pH buffer to culture medium increased the numbers of shoot formation. Adding 5g/l of anti-vitrifying agent into culture medium was highly effective for diminishing the rate of vitrification in shoots formed.