Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal Basic Information
Journal DOI :
Korean Society for Biotechnology and Bioengineering
Editor in Chief :
Volume & Issues
Volume 11, Issue 6 - Dec 1996
Volume 11, Issue 5 - Oct 1996
Volume 11, Issue 4 - Aug 1996
Volume 11, Issue 3 - Jun 1996
Volume 11, Issue 2 - Apr 1996
Volume 11, Issue 1 - Feb 1996
Selecting the target year
Effect of Ammonium Phosphate Concentration on the Growth of Recombinant E. coli
KSBB Journal, volume 11, issue 4, 1996, Pages 389~397
The growth of recombinant E. coli and formation of the by-products were investigated. Ammonium phosphate is known to affect the cell growth as well as the enzyme formation. When initial ammonium phosphate concentration was 0.5g/L, cell mass was 4.1g/L. By adding tryptone to the medium, acetic acid formation increased while lactic acid formation decreased. In cultivating recombinant E. coli, lactic acid and acetic acid turned out to be important by-products which affected cell yield and growth rate. Initial ammonium phosphate and tryptone concentration were optimized in our research and can be applied for other culture of recombinant E. coli.
Encapsulation of Whole Cell
-Galactosidase of Escherichia coli
KSBB Journal, volume 11, issue 4, 1996, Pages 398~404
Escherichia coli was inoculated in calcium alginate capsules and cultivated to prepare encapsulated whole cell
-galactosidase. The dry cell weight in the capsule reached 100 g/L based on the inner space of the capsule. The activity of the encapsulated whole cell
-galactosidase increased with the dry cell weight increase during cultivation in the production medium. The activity of the encapsulated whole cell
-galactosidase was increased 25% by adding
ion in the production medium and 10% by coencapsulating with 2% (v/v) sunflower seed oil. The activity of encapsulated whole cell
-galactosidase produced in the concentric air lift reactor in which kLa was 82/hr was 86% higher than that in the shaking flask incubator where kLa was 2.55/hr.
Effect of Geometric and Dynamic Parameters on Mixing Characteristic in an Internal-Loop Apparatus
KSBB Journal, volume 11, issue 4, 1996, Pages 405~410
This paper discussed the dispersion effect according to the geometrical variation of an internal-loop spparatus by the method of pulse injection of a tracer. The Bodenstein number, which is the dimensionless group characterizing the effect of dispersion, was decreased with increasing the superficial gas velocity in the 50L and the 500L apparatus. But, in the 5L apparatus, the Bodenstein number was increased with increasing the superficial gas velocity in the range of 0 to 2cm/sec but above that range the rate of increase was dropped down to give a constant value because of the phenomenon of gas disengagement. The principle of similarity based on dimensional analysis was applied to design a pilot scale internal-loop apparatus. The effect of dispersion was examined in three different internal-loop apparatus to give the following correlation with major geometric and fluid dynamic properties as variables. B0=4.4014ReG0.117 ReL-0.0065(Hr/Dr)0.76(Dd/Dr)-0.76
Production Enhancement of Benzophenanthridine alkaloids in the Suspension Cultures of California poppy using Cyclodextrin
KSBB Journal, volume 11, issue 4, 1996, Pages 411~419
In this research, an extractive production system for alkaloids, where production and some degree of separation occur simultaneously, was developed in a way that the fast removal of alkaloid produced from the suspension cultures was done by capturing alkaloid with cyclodextrins. The alkaloid production was substantially enhanced up to 40 fold when the solid cultures of E. califonica cells treated with
-cyclodextrin compared to the control. The enhancement of alkaloid production was also observed in the suspension cultures. Interestingly, the production pattern seemed to change when the cultures were treated with
-cyclodextrin so that the major part of the alkaloids in the treated cultures was present in the medium, while the non-treated cultures produced the alkaloids intracellularly.
-cyclodextrin was the most effective one in terms of the alkaloid production among the cyclodextrilns(
-cyclodextrin) tested in the suspension cultures.
-cyclodextrin showed no adverse effect on the cell growth. The most effective concentration of
-cyclodextrin was observed around 1.5% (w/v) in the suspension cultures. The formation of the inclusion complex of the alkaloids with
-cyclodextrin in the suspension cultures was confirmed by detecting the shift of UV absorbance from 274 nm to 282 nm with a UV spectrophotometer.
Development of One-Step Immuno-Chromatography Assay System for Salmonella typhimurium
KSBB Journal, volume 11, issue 4, 1996, Pages 420~430
One-step immuno-chromatography assay system for heat-killed Salmonella typhimurium antigens was developed. Three major components used were a glass fiber membrane (placed at the bottom of the system) with an antibody (specific to the analyse, detection antibody)-gold conjugate deposited in a dry state on the surface, a nitrocellulose membrane (middle) with an antibody (also, specific to the analyse but recognized different epitome: capture antibody) and anti-detection antibody immobilized in spatially separated areas, and a cellulose membrane (top) as absorption pad. These membranes were partially superimposed such that a wicking of aqueous solution containing sample can continuously take place through membranes. Variables that affected the system performance were the concentration of capture antibody, the location on the membrane, inert protein used for blocking of the membrane and for carrying the sample, and the concentration of the gold conjugate. Under optimal conditions, within 15 minutes after absorption of a sample solution from the bottom of the system antigen-antibody complexes of sandwich type were formed on the membrane surface area with immobilized capture antibody and a color signal was generated in proportion to the analyse concentration. The minimum do tection limit of the analyse was
Characterization of the Nar Promoter Modified by Site-directed Mutagenesis to Use as an Expression Promoter
KSBB Journal, volume 11, issue 4, 1996, Pages 431~437
The nar promoter of Escherichta coli, which is maximally induced under anaerobic conditions in the presence of nitrate, was characterized to see whether the nar promoter cloned onto pBR322 can be used as an expression promoter. The modified nar promoter, in which several bases in the -10 region was mutated to the consensus sequence by site-directed mutagenesis, was characterized in E. coli, on which chromosome the fnr gene affecting expression of the nar promoter according to dissolved oxygen level was mutated. The E. coli lacZ gene was used as a reporter gene. The following effects were investigated to find optimal conditions to induce the modified nar promoter: induction methods, optimal nitrate concentrations, the amount of
-galactosidase expressed at the different growth conditions, and induction characteristics. The following results were obtained from the experiments : expression of
-galactosidase from the modified nar promoter was not affected much by nitrate concentrations. The maximal specific
-galactosidase activity was obtained when E. coli was grown under aerobic conditions, and then the modified nar promoter was induced at OD600=2.2 under microaerobic conditions (DO=1∼2%), under which conditions the maximal specific
-galactosidase activity was 13,000 Miller units. However, the specific
-galactosidase activity was approximately 6,000 Miller units even before the modified nar promoter was induced. Therefore, the modified nar promoter seemed to be useful when the cloned gene wants to be expressed in E. coli constitutively.
Optimization of Host Animal Cell Culture Conditions to Produce Protein Using Recombinant Vaccinia Virus
KSBB Journal, volume 11, issue 4, 1996, Pages 438~444
Using recombinant Vaccinia virus(vSC8) that express
-galactosidase, a model heterologous protein, conditions for virus and protein production were investigated in tissue culture flask. As host animal cells HeLa and HeLa S3 were used. It was demonstrated that cells infected during the exponential growth phase gave higher protein yield than those infected during the stationary growth phase and calf serum concentration after virus infection did not significantly alter protein yield. Pretreatment of cell layer with hypotonic solution enhanced the virus infectivity. Optimum cell growth and recombinant protein production was achieved at
. But, during 2 hours of virus infection period incubation temperature must be lowered to 20∼
for maximum recombinant protein yield. To enhance virus replication, the effects of adrenal glucocorticoid hormone (Dexamethasone) and silkworm hemolymph were evaluated. Only dexamethasone increased about 20% of
-galactosidase yield in HeLa S3 cells when added with 10-7∼10-5M concentration 24 hours before infection.
Expression and Secretion of Recombinant Inulinase under the Control of GAL or GAP Promoter in Sacharomyces cerevisiae
KSBB Journal, volume 11, issue 4, 1996, Pages 445~452
To investigate the promoter effect on heterologous gene expression in S. cerevisiae, the recombinant plasmids pYI11, pYI12, pYI10-2, and pYIGP were constructed to contain the inulinase gene (INUI) as a reporter under the control of GAL10, GAL7, GAL1, and GAP promoters, respectively. When the yeasts transformants were cultivated on galactose-containing rich media, the cell growth reached to 36-39 OD600 at 72 hours of cultivation. The specific growth rates of the cells harboring the four different plasmids decreased similarly : they dropped from
during the glucose-consuming period to 0.04 -
during the galactose-consuming period (gene expression phase for GAL promoter system). After the depletion of glucose, the expression of inulinase gene was started and reached to maximal levels of 4.3(GAL1 promoter), 4.0(GAL10 promoter), 3.8(GAL7 promoter), and 1.6(GAP promoter) unit/mL at 72 hours of cultivation. Based on the maximal expression level and activity staining on the plate, the promoter strength was in the order of GAL1, GAL10, GAL7 and GAP promoter. While the GAL-promoter systems showed a high plasmid stabilities of more than 78%, the GAP-promoter plasmid revealed a lower plasmid stability of 55%. Most of inulinase activity (98%) was found in the extracellular medium, indicating that the secretion efficiency of inulinase is independent on the type of promoter.
Comparison of Single and Sandwich Collagen Gel on the Survival and Metabolism of Rat Hepatocytes Primary Cell Culture
KSBB Journal, volume 11, issue 4, 1996, Pages 453~461
We compared the effects of two different systems of collagen matrix protein application on the survival and the biological functions of cultured primary hepatocytes. The rat liver primary hepatocytes were grown for approximately 40 days in vitro either on single collagen gel or between collagen sandwich gels. The morphological changes were observed for this culture period. While the hepatocytes grown on single gel began to die around at 7 days of culture, the cells grown between collagen gels still maintained their viability and began to die after 15 days. As markers for liver hepatic functions, we determined the biochemical activities of hepatocytes such as the secretions of albumin, fibronectin, fibrinogen, urea, and the reduction of secreted ammonia. We found that the rat hepatocytes cultured between collagen gels maintained fairly good biochemical functions than the hepatocytes cultured on single gel did. Therefore, the application of an extracellular matrix protein, collagen, in sandwich form was confirmed as a better choice for maintaining the functional hepatocytes culture for long term in vitro.
Effects of Culture Condition on Solubilization of Coal by Microorganisms
KSBB Journal, volume 11, issue 4, 1996, Pages 462~469
Biosolubilization of an Australian lignite was investigated by using Streptomyces viridosporus and Poria cocos. In order to solubilize coals effectively they were pretreated by nitric acid both in surface and liquid cultures. The optimum growth pH was 7.5 for S. viridosporus and 4.5 for P. cocos. The effects of various carbon, nitrogen and metal sources on overall solubilization were also studied. Solubility increased with the addition of urea for S. viridosporus, and peptone and tryptone for P. cocos. However carbon and metal sources had little or negative effects on solubilization. Maximum amount of coal solubilized was 85%(w/w) in a batch fermentation culture. Extracellular materials produced by micro-organism were found to be responsible for the coal solubilization. Approximately 70 to 80% of coal solubilization was determined to be the result of non-enzymatic reactions, and the rest to be the result of enzymatic reactions. Characteristics of the solubilized coal were compared with those of original coal and pretreated coal by the approximate and ultimate composition analysis, and IR-spectrum analysis. The spectroscopic results showed that the mechanism of coal solubilization was caused by continuous oxidation.
Culture Conditions and Flocculating Activity of Exo-biopolymer Produced by Pestalotiopsis sp. KCTC 8637p
KSBB Journal, volume 11, issue 4, 1996, Pages 470~475
A white rot fungus as a microbial source producing bioflocculant was isolated from rotted leaves and identified as Pestalotiopsis sp. M01. The flocculating activity and productivity of Pestan produced by Pestalotiopsis sp. KCTC 8637P was determined by using Czapek-Dox medium as the inorganic salt source. The flocculating activity was highest at 3% sucrose and 0.3%
, pH 7, and
, respectively. Whilst, the strain growth was highest at 3% sucrose, 0.3% TEX><$KN0_3$, pH 5, and
Treatment of Wastewater Containing Phenol Using Pseudomonassp. B3
KSBB Journal, volume 11, issue 4, 1996, Pages 476~480
Using Pseudomonas sp. B3, identified and isolated from nature, wastewater containing phenol was treated in a continuous stirred tank reactor and its reaction characteristics were studied. Average concentrations of phenol and COD in effluents were 1.5mg/L and 124mg/L at 0.059h-1 dilution rate, respectively. At the dilution rate higher than 0.063h-1, phenol and COD increased abruptly to 19mg/L and 318mg/L. At the dilution rate higher than 0.059h-1, biomass concentration suddenly decreased and was "washed out". Biomass concentration was 150mg/L at a dilution rate of 0.067h-1. Maximum biomass production rate was 15.98mg/L
h at a dilution rate of 0.067h-1. When dilution rate increased above 0.059h-1, effluent phenol concentration abruptly increased and biomass production rate decreased. Maximum cell growth rate(
max) and Michaelis-Mentens kinetic constant(Ks) were 0.074h-1 and 0.424mg/L, respectively. From the above result low phenol concentration can be expected at a maximum dilution rate, but reactor becomes unstable due to phenol inhibition.
Preparation and Characterization of Microcrystalline Chitin from Crab Shell
KSBB Journal, volume 11, issue 4, 1996, Pages 481~488
In spite of diverse applications of chitin derivatives, commercial use of chitin has been limited due to highly resistance to chemicals and the absense of proper solvents. One of methods to reduce such high resistance to chemicals is to make microcrystalline chitin(MCC) by hydrolysis of chitin. Presently, MCC is produced mainly by using high concentration of acid, but this treatment requires an extensive posttreatment to remove or recover acid. An alternative process for MCC production was developed by using dilute hydrochloric acid with ultrasound and hydrogen peroxide. The major parameters for this process were found to be acid concentration, swelling time and temperature, and irradiation time and frequency of ultrasound. The effects of these parameters on MCC molecular weight were investigated. The molecular weight of MCC produced at a typical condition was around 30,000 which was approximately 1/8 of that of chitin and approached to a constant value. This phenomenon was explained by introducing the model of molecular arrangement of cellulose. SEM analysis showed that both chitin and MCC had a fibrous shaped morphology and the fibril size of MCC was much smaller than that of chitin.
Electrocatalytic Properties of Metal-dispersed Carbon Paste Electrodes for Reagentless L-lactate Biosensors
KSBB Journal, volume 11, issue 4, 1996, Pages 489~496
Metal dispersed carbon paste electrodes were fabricated, and their electrochemical properties were investigated. Among various metal dispersed carbons, platinum-dispersed carbon paste electrode showed most efficient electrocatalytic characteristics. The overpotential for the oxidation of NADH was significantly lowered in the platinum-dispersed carbon paste electrode, and catalytic current was also enhanced. Based on these electrocatalytic observations, L-lactate biosensor using L-lactate dehydrogenase was constructed to evaluate its performance in terms of sensitivity and stability.
Effects of pH and Nitrogen sources on the Pullulan Production by Aureobasidium pullulans
KSBB Journal, volume 11, issue 4, 1996, Pages 497~503
In this study, the effects of nitrogen sources and pH on pullulan production were investigated. As a result, the best nitrogen source in pullulan production by Aureobasidium pullulans was shown to be peptone and its product yield was 62%. Optimum concentration of carbon/nitrogen source ratio was 50/0.15 and the production of pullulan was inhibited at ratios higher than 50/0.15. Aureobasidium pullulans had produced 29.1, 27.4 and 26.5 g/L pullulan, respectively in media I, II, and III containing mixed nitrogen sources. This result showed that pullulan could be produced efficiently from mixed nitrogen source. It was found that pullulan yield with pH control was higher than that with no pH control. In fedbatch fermentation, pullulan yield obtained with a feeding rate of 0.05 N-g/L for nitrogen source was higher than that without nitrogen source feeding.
Screening of Promoter Sequences from Lactic Acid Bacteria Using a Promoter-Selection Vector
KSBB Journal, volume 11, issue 4, 1996, Pages 504~509
Promoters which are useful for constructing expression vectors for lactic acid bacteria were obtained from the chromosomal DNA of Lactococcus lactis ssp. lactis MG1363. pBV5030, a promoter-selection vector, replicates in L. lactis and Escherichia coli and carries a promoterless chloramphenicol acetyltransferase gene (cat-86). After examining E. coli transformants which grew on LB media containing chloramphenicol (Cm, 20
/mL) , many MG1363 derived DNA fragments which encompass promoter sequences were identified. Some recombinant E. coli cells can grow at the Cm concentration of 1,000
/mL. When plasmids from those highly resistant E. coli cells were purified and introduced into L. lactis ssp. lactis MG1614 cells by electroporation, lactococcal transformants showing Cm resistance were obtained. So far, five plasmids with different promoter inserts were introduced into L. lactis MGl614 cells. The maximum level of Cm resistance in L. lactis MG1614 transformants was quite low (20
/mL) when compared with that observed in recombinant E. coli cells harboring the same plasmids.