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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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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
Effects of Concentration of Inhibitor on the Production of
-amylase and Growth of Bacillus amyloliquefaciens
KSBB Journal, volume 11, issue 2, 1996, Pages 125~131
In this study, Bucillus amyloliquefaciens was adopted as bacterial source to investigate the concentration of carbon source by adding inhibitors in the batch culture. By adding acetic acid at
of initial glucose concentration, maximum dry cell density was obtained with the highest value of /
of initial acetic acid concentration. By adding acetic acid al 10g/
of initial glucose concentration, maximum
-amylase production was obtained with 331.55unit/m1 at
of initial acetic acid concentration.
-Amylase production was decreased with the increase of initial acetic acrid concentration. By adding acetic acid to the medium, cell growth and
-amylase production was higher in glucose than in maltose. By adding lactic acid to the medium, cell growth was decreased.
Effects of Inhibitor Concentrations on the Growth of Recombinant E. chli
KSBB Journal, volume 11, issue 2, 1996, Pages 132~139
The growth of recombinant E. coil and by-product production were investigated. D-cycloserine was added to increase the secretion of
-amylase from recombinant E.coil. Even though cell growth was increased for optimal d-cycloserine concentration
-amylase activity remained almost the same as the case without d-cycloserine. It is important to achieve the high cell density for commercial production of methaboliles including
-amylase. To achieve this goal, culture conditions should be selected carefully and optimized considering cell growth and by-products production. In cultivating retombinant E. coli, lactic acid and acetic acid turned out to be important by-product which affected cell yield and growth rate.
Development of Membrane Strip Assay System for Lipoprotein Cholesterol
KSBB Journal, volume 11, issue 2, 1996, Pages 140~150
To develop a home-version assay system for plasma lipoprotein cholesterol, variables that can control the assay performance were optimized. The system was constructcd by using two major components: nitrocellulose membrane strip with immobilized enzymes (cholesterol esterase, cholesterol oxidase, and horseradish peroxidase); and sample carrier solution containing non-ionic detergent (Triton X-100) and chromogen (3,3'-diaminobenzidine). Once a sample combined with the carrier was absorbed from the bottom of the strip, cholesterol was delivered by capillary action to the immobilized enzymes and a sequential reactions took place. In the final reaction, the chromogen was oxidized and then generated a color as signal that was proportional to the concentration of cholesterol. The signal intensity was enhanced by optimizing conditions for the immobilization of enzymes and the chemical composition of carriel. Under these conditions, a dose-response curve was obtained and revealed a high sensitivity enough to measure the cholesterol in blood.
Kinetic Modeling of the Enzymatic Hydrolysis of
-Cellulose at High Sugar Concentration
KSBB Journal, volume 11, issue 2, 1996, Pages 151~158
For the effective ethanol fermentation, the high concentration of sugar as the substrate of microbial fermentation is required. The most important reason in the inefficient hydrolysis; the easy deactivation of enzyme by temperature or shear stress and the severe inhibition effects of its products. In our work, we comprehended the kinetic characteristics of cellulose and
-glucosidase in the progress of hydrolysis, and observed the potential inhibitory effects of the hydrolyzed products and the deactivation of enzymes. We also tried to present the kinetic model of enzymatic hydrolysis of cellulose, which is applicable to process at the high concentration of sugar. Cellulase and ,
-glucosidase exhibit diverse kinetic behaviors. At a level of only 5g/
of glucose, the
-glucosidase activity was reduced by more than 70%. This result means that
-glucosldase was the most severely inhibited by glucose. Also at l0g/
of cellobiose, the cellulose lost approximately 70% of its activity.
-glucosldase was more sensitive to deactivation than cellulose by about 1.6 times. The comprehensive kinetic model in the range of confidence was obtained and the agreement between the model prediction and the experimental data was reasonably good, testifying to the validity of the model equations used and the associated parameters.
Production of Bio-Diesel Fuel by Transesterification of Used Frying Oil
KSBB Journal, volume 11, issue 2, 1996, Pages 159~164
Transesterification of used frying oil was investigated to produce the bio-diesel oil. Experimental conditions included molar ratio of used frying oil to alcohol (1:3, 1:5 and 1:7), concentration of catalyst (0.5, 1.0 and 1.5 wt.%), ippe of catalyst(sodium melhoxide, NaOH and KOH), reaction temperature (30, 45 and
), and types of alcohol(methanol, ethanol and butanol). The conversion of used frying oil increased with the alcohol mixing ratio and with the reaction temperature. The effect of the type of catalysts on conversion was not significant. The highest conversion was obtained when methanol was used as alcohol. Viscosity was a little higher with the ester product over grade #2 diesel oil. But the physical properties improved significantly with transesterification, resulting in similar fuel properties with those obtained for grade #2 diesel fuel.
Export of Human Proinsulin in E. coli : High Export of Proinsulin Fusion Protein but not of Proinsulin Itself
Yup Kang ;
KSBB Journal, volume 11, issue 2, 1996, Pages 165~172
To obtain a correctly folded human proinsulin, export of proinsulin using Staphylococcal protein A signal sequence-mediated secretion pathway has been attempted in E.coli. A secretion operon for proinsulin was constructed by consecutively connecting T7 promoter, SPA ribosome binding site, SPA signal sequence gene, and human proinsulin gene. Little immunoreactive proinsulin was detected in the periplasmic space and. culture medium, and not even in cytoplasmic space. The qualitative analysis of transcribed proinsulin mRNA and the in vitro transcription/translation experiment suggests that the negligible level of proinsulin export appears to be due to intracellular degradation of proinsulin, rather than due to the blockage during translocation. However, expression of proinsulin fusion protein such as MBP-proinsulin could dramatically increase export of proinsulin in E.coli.
Pb Biosorption by Saccharomyces cerevisiae
KSBB Journal, volume 11, issue 2, 1996, Pages 173~180
The contamination of the environment by heavy metals results in a serious public health problem due to the toxicity of those pollutants even at low concentrations. Microorganisms may be used to remediate wastewaters contamlialtd with heavy metals. The waste S. cerevisiae is an inexpensive readily available source of biomass for bioremediation of wastewater. S. cerevisiae was investigated for their ability to absorb Pb. The crushed biomass of S. cerevisiae exhibited higher Pb uptake capacity than the living S. cerevisiae and the sterilized S. cerevisiae. At the same metal concentration, metal uptake per unit concentration or adsorbent decreased when the biomass concentration rises. The order of the biosorption capacity of the living S. cerevisiae was Pb>Cu>Cd=Co>Cr. When S. cerevisiae was pretreated with 0.1 M NaOH, Pb uptake was increased by 150 percent and 0.1 M HC1, 0.1 M
solutions were efficient in the desorption of Pb. The sorption equilibrium of Pb ions can be described by the Freundlich and Langmuir models.
Effect of O1igosaccharides on Mannitol Accumulation during the Fermentation of Kimchis
KSBB Journal, volume 11, issue 2, 1996, Pages 181~185
A considerable amounts of mannitol were accumulated during the fermentation of Kimchis. When several oligosaccharide including fructo-, soybean-, and isomaltooligosaccharides were added during the preparation of Kimchi as beneficial ingredient respectively, fructooligosaccharides (at
) and soybean-oligosaccharides (at
) significantly increased the amounts of mannitol accumulation, while isomalto-oligosaccharides exerted no effect at all fermentation conditions examined. This result were caused by no appearance of microorganisms which have the capability of utilizing isomalto-oligosacsharides during fermentation period. Isomalto-oligosaccharides can be recommended as an effective ingredient of Kimchis because both oligosaccharides and mannitol that have favorable functionalities were simultaneously contained. However, so as to enhance the cooling taste of Kimchis by increasing the content of mannitol, fructo- and soybean-oligosaccharides are rather favorable.
Stabilization of Subtilisin Carlsberg in Polar Organic Solvents by Chemical Modification
KSBB Journal, volume 11, issue 2, 1996, Pages 186~192
The effects of chemical modification on the enzymes' stability in polar organic solvents were studied with subtilisin Carlsberg in dimethylformamide-water mixtures as a model system. Three out of nine lysine residues of subtilisin Carlsberg were coupled to either trimellilic or pyromellitic anhydrides thereby, for each lysine residue modified, resulting in the net replacement of one basic amino group by two or three acidic carboxyl groups, respectively. In water at 60
, both trimellitic and pyromellitic anhydride-modified subtilisin Carlsberg showed increased thermostability by 2.6 times and 1.6 times, respectively, as compared to that of unmodified enzyme. In 70% dimethylformamide at 25
, however, only pyromellitic acrid was shown to enhance the stability of subtilisin Carlsberg by 5.5 times increasing the half life time of irreversible inactivation from 4.9hr for unmodified enzyme to 27.8hr for modified enzyme.
Alteration of Recognition Sequence by Restriction Endonuclease -Effect of pH and Hydrophobicity on BamHI-
KSBB Journal, volume 11, issue 2, 1996, Pages 193~200
In molecular biology, type-II restriction endonuclease, which specifically recognize and cleave DNA at a limited number of sites, have been exploited as a means of characterizing DNA fragments, DNA mapping for genetic engineering. Type-II restriction endonucleases have been found to modulate their substrate specificity under modified conditions such as extreme pH, ionic strength, high enzyme concentration, substitution of metallic cofactors or addition of organic solvents. This study was initiated to investigate the modification of recognition specificity of BamHI according to the different pH and organic solvent under the given buffer condition. The specificity of BamHI is highly depends on the presence of hydrophobicity (LogP: partition coefficient) and pH of reaction solution. The specificity of BamHI is changed in range of LogP -1.03∼-1.35(at pH 7.5), -1.03∼-2.5 (at pH 8.0), -0.75∼-0.25(at pH 8.5), 0.32∼-2.5(at pH 8.9), respectively. Alteration of specificity appears in lower concentration of organic solvent when the reaction occurs in more alkali pH. For example, in DMSO solution, alteration of specificity appears in 20% concentration at pH 7.5 but in 4% concentration at pH 8.9.
Fed-Batch Culture for Polyhydroxyalkanoate Overproduction by Pseudomonas sp. HJ
KSBB Journal, volume 11, issue 2, 1996, Pages 201~210
The production of polyhydroxyalkanoate(PHA) from glucose by batch and fed-batch culture of Pseudomonas sp. HJ was studied. In batch culture using fermentor, 400 rpm of agitalion speed, 2 vvm of aeration rate, 18 hours of inoculum age, and 5% (vlv) of inoculum size were optimal. PHA production was not increased by deficiency of oxygen. In a batch culture, the final call mass was
, and PHA content was 20% of dry cell weight. In a constant feeding fed-batch culture, cell mass increased to
, and PHA content reached 48.9% of dry cell weight. In an intermittent feeding fed-batch culture, cell mass increased to
, and PHA content reached 53.5% of dty cell weight.
The Effect of Electron Donor on Reductive Dechlorination of Chlorophenols
KSBB Journal, volume 11, issue 2, 1996, Pages 211~217
Batch experiments were conducted to investigate the effect of electron donor on reductive dechlorination of 2,4,5-trichlorophenol by a methanogenic consortium. The methanogenic consortium was obtained from the anaerobic digester of a municipal wastewater treatment plant. The batch reactor containing methanogenic consortium was spiked with 2,4,6-trichlorophenol at 10 mg/
. Acetate, ethanol, glucose of methanol, each was added as an electron donor for methanogenic consortium. During the course of the experiments liquid samples were taken from the batch reactor to measure dechlorination rate and find the dechlorination pathway of 2,4,6-trichlorophenol. After incubation 2,4,6-trichlorophenol was first dechlorinated to 2,4-dichlorophenol and then to 4-chlorophenol. Phenol was not detected in the batch reactor the highest rate of dechlorination of 2,4,6-trichlorophenol was observed when ethanol was used as an electron donor.
Adsorption Behaviors of Cellulose on Cellulose with Different Crystallinities in Nonionic Surfactant Solution
KSBB Journal, volume 11, issue 2, 1996, Pages 218~224
The adsorption of cellulase on celluloses with different crystallinities was carried out In nonionic surfactant(Tween 20) solution. Highly crystallized celluloses were prepared by enzymatic prehydrolyzation. From the experiments, the Langmuir isotherm parameters, maximum adsorption amount (Amax) and adsorption equilibrium constant(Kad) for the adsorption, were obtained in the presence and absence of nonionic surfactant. It was found that the Kad values were decreased by adding Tween 20. This indicates that the adsorption affinity is reduced by nonionic surfactant, and Amax decreased with increasing crystallinity under conditions accompanying in both the presence and absence of surfactant. The thermodynamic parameters such as
Sa for the adsorption were calculated by using the experimental data. From these results, it was found that the adsorption processes are exothermic reactions in both the presence and absence of surfactant. The heats of adsorption in surfactant solution(-4.68∼-3.62KJmol-1) are smaller than that of the adsorption in the absence of surfactant(-15.60∼-12.10KJmol-1). These results indicated that the tightness of adsorption was reduced by the addition of surfactant. The
Sa values were estimated to be positive. This may suggest that the water and solute are released from cellulose on adsorption. The
Sa values in surfactant solution are larger than that of the adsorption in the absence of surfactant. This may suggest that the binding of surfactant on hydrophobic region of cellulase cause dispersion of water and solute molecule orienting around the enzyme molecule. The surfactant played an important role in the desorption of enzyme from cellulose functional groups, and enhance the saccharification of the cellulose.
Kinetics of 125I-BSA Binding to Monoclonal Anti-BSA Immobilized on
KSBB Journal, volume 11, issue 2, 1996, Pages 225~237
Intrinsic binding kinetics of of 125I-bovine serum albumin (125I-BSA) and immobilized monoclonal anti-BSA (MAb 9.1) were studied. Small non-porous polystyrene beads (0.5
m diameter) were used as a solid support to minimize the mass transfer interference on rate measurements. We demonstrated both theoretically and experimentally that the binding reaction is kinetically controlled. Rate measurements show that the association reaction is of second order and the dissociation reaction is of first order. Between 4 and
the measured equilibrium constant agrees well with the equilibrium constant calculated from the rate measurements. The temperature effects on association are much greater than on dissociation; the activation energy for association is about 9Kca1/mole, as compared to 2Kca1/mole for dissociation. The use of small non-porous beads as a solid support in binding studies essentially avoids mass transfer limitations; such a system makes it possible to determine the intrinsic binding characteristics of any immobilized antibody on a solid surface.
Microbial Desulfurization of a Bituminous Coal by Iron-Oxidizing Bacteria Thiobacillus ferooxidans
KSBB Journal, volume 11, issue 2, 1996, Pages 238~245
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.
Production of poly-
-hydroxybutyric acid(PHB) from Liquefied Natural Gas using an Obligatory Methanotroph Methylosinus trichosporium OB3b
KSBB Journal, volume 11, issue 2, 1996, Pages 246~253
An obligatory methanotroph Methylosinus trichosporium OB3b was cultivated for the production of poly-
-hydroxybutyric acid(PHB) in shake-flask using liquefied natural gas(LNG) as the sole source of carbon and energy. The maximal specific growth rate decreased by 40% using LNG compared with that obtained with pure methane. This is attributed to the inhibition by ethane and propane presents in the LNG as impurities. For the production of PHB, two-stage culture separating the production stage from the growth stage was carried out. PHB accumulation was observed after switching nutrient-sufficient to nutrient-limited condition of non-carboneous component (NO3-, PO43-, K+, Na+, Fe2+, or Mg2+). The limitation of K+ or Mg2+ resulted in relatively high PHB content, but the highest content was obtained by nitrate limitation. The optimal pH and temperature for PHB accumulation was 7.0 and
. Under the optimal condition the maximal PHB content was about 45% after 4-day cultivation.
Production of Varicella-zoster Virus Using Human Lung Fibroblast Cells As Host Cells
KSBB Journal, volume 11, issue 2, 1996, Pages 254~261
Attenuated varicella-zoster virus (VZV) was propagated in human lung fibroblast (HLF) cells Among media tested in this work, DMEM was the best medium for the growth of HLF cells. Because HLF was a normal finite cell line, cell growth late was dependent on the age of HLF cells. When the population doubling level (PDL) was higher than 46, apoptosis of HLF cells started and cell growth rate decreased. The optimum temperature for the cell growth and virus propagation in the T-flask culture was
. In a microcarrier culture system in which Cytodex-3 was used for the VZV propagation in spinner vessels, the yield of plaque forming cells was lower than that in the T-flask culture. The relatively high shear environment near microcarriers was thought to cause the low yield of VZV in the microcarrier culture system.