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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal DOI :
Korean Society for Biotechnology and Bioengineering
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Volume & Issues
Volume 19, Issue 6 - Dec 2004
Volume 19, Issue 5 - Oct 2004
Volume 19, Issue 4 - Aug 2004
Volume 19, Issue 3 - Jun 2004
Volume 19, Issue 2 - Apr 2004
Volume 19, Issue 1 - Feb 2004
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Production of Yeast Extract by a Combined Method of Autolysis and Enzymatic Hydrolysis
KSBB Journal, volume 19, issue 4, 2004, Pages 245~249
A combined method of autolysis and enzymatic hydrolysis of baker's yeast was developed for the production of yeast extract, which is widely used as a natural food ingredient. From statistical analysis, NaCl and ethanol addition were found to be significantly effective factors in autolysis of yeast. The optimum dosages of salt and ethanol were 3% and 1%, respectively. Heat treatment and the use of cell lytic enzyme were not significantly effecting on the autolysis. Yeast hydrolysate was prepared by autolysis, followed by enzymatic hydrolysis using proteases, nuclease and deaminase. Additionally, the hydrolysate was processed by downstream process including Maillard reaction and debittering. The total dry matter yield and total nitrogen yield for the process were 76% and 59%, respectively. Compared to a process using brewer's yeast, when baker's yeast was used as a raw material, a higher recovery yield was obtained.
Production of a Phospholipase C by Bacillus cereus and Its Characterization
KSBB Journal, volume 19, issue 4, 2004, Pages 250~256
In this work we have cultivated several B. cereus strains in a complex LB medium in order to study the production of phospholipase C (PLC), and among them B. cereus 318 showed the highest productivity of PLC. Some components, i.e., 5 g/L glucose, 5 g/L yeast extract, 5 g/L peptone, 0.5∼1.0 g/L K
, 0.02∼0.04 g/L ZnSO
O and 3 g/L NaHCO
were found to be optimal for the high production of PLC by B. cereus 318. Optimal culture temperature and pH were found to be 30
and pH 7.5 for the PLC production, respectively. Optimum reaction temperature and pH of the PLC produced by B. cereus 11 and 318 were 45
and pH 4.0, while they were 50
and pH 7.0 for the PLC by B. cereus 559. The PLC produced by B. cereus was activated by Mn
2+/ and dimethyl sulfoxide (DMSO), but its activity was inhibited by Cu
2+/ and partially by glycerol, isopropanol and sodium dodecyl sulfate (SDS).
A Study on the Design Criteria of Photobioreactor for the Efficiency of Light-Utilization
KSBB Journal, volume 19, issue 4, 2004, Pages 257~262
Recently, there is a growing interest in microalgae and the use of microalgae focused on the production of various high value metabolite used in food, pharmaceuticals and cosmetics. The key limiting factor in high density algal cultivation is the light and algal growth is defined by light intensity and light penetration depth into the culture medium. The effect of light with various light paths, S/V ratios, light intensities, and 50% duty cycle on the growth of microalgae was examined to enhance microalgal biomass productivity and photosynthetic efficiency. We confirmed that the utilization of efficient light energy was obtained from 4 cm of diameter, 57.6% of S/V ratio, 62
mol/㎡/s of light intensity.
Chiral Separation of Ibuprofen by Supercritical Fluid Chromatography
KSBB Journal, volume 19, issue 4, 2004, Pages 263~268
The separation method using chiral stationary phase in preparation of chiral compound was wildly used, but in this work, supercritical fluid chromatography was suggested in the stability to resolve the chiral mixtures. To determine the optimum operating condition of the racemic ibuprofen, the retention factor and resolution with change in pressures, temperatures and the contents of IPA % (vol.) in CO
were investigated. The retention factor was decreased with increase in pressure and decrease in temperature. The factor was also influenced by the content of IPA in mobile phase, while the resolution was worse with a increase in IPA %. From the experimental results, the desirable separation condition was 130 bar, 311.15 K and 4% IPA in CO
. Compared to the asymmetric peak shape by liquid chromatography, that of supercritical fluid chromatography was symmetric which was a favorable condition for preparative separation.
Simple and Quantitative Analysis Method for Total Carbohydrate Concentration in Oligosaccharides by using TLC
KSBB Journal, volume 19, issue 4, 2004, Pages 269~273
A simple, fast and reproducible quantitative analysis method for sugar concentration composed in oligosaccharide mixture was developed. Two glass TLC plates were prepared per sample. After dipping one plate into the copper bicinchoninate reagent and the other plate into 5% sulfuric acid solution, both plates were baked in microwave oven until sugar spots were developed or the surface temperature of TLC plate becomes 60 to 70
. The corrective factor values [F value =(the value of total sugar concentration converted as glucose unit/the value of reducing sugar concentration converted as glucose unit)/(polymerization degree of sugar)] of different molecular weight sugars were determined. Within the concentration of 0.25∼1.0
in each sample loaded, the fructose-F (corrective factor value of fructose) was 0.45, yet for the higher concentration (2.5∼7.5
) fructose-F was 1.0. In case of glucose, in the range of 0.5∼7.5
, glucose-F was same as fructose-F, 1.0. However, as the molecular weight of sugar was increased, the F values were decreased in both maltodextrin and isomaltodextrin oligosaccharides in 0.5∼7.5
of each sample loaded. Interestingly, F values were equal for the same molecular weight sugars, although the structures were different from each other. Using F value of each sugar, we could determine and compare the exact total sugar concentration of different molecular weight maltooligosaccharide and isomaltooligosaccharide. We also could determine if the unknown sugar was a reducing or non-reducing compound by using optimized TLC with microwave oven method.
Pharmaceutical Characteristics of Korean Lumbricus rubellus Lumbrokinase
KSBB Journal, volume 19, issue 4, 2004, Pages 274~283
Six lumbrokinase (LK) fractions from Lumbricus rubellus lysates were purified by a series of column chromatographies. The molecular weights of the six LK fractions appeared to range from 24.6 to 33.1 kDa. In the experimental model of rat venous thrombosis, the thrombus weight and PAI activity decreased significantly when the LK was administered orally. However, the activities of APTT, PT and plasmin showed a significant increase. The aggregation of rat platelets pretreated with various LK doses was inhibited by thrombin, and the MDA generation decreased. The rat thoracic aorta and mesentric arteries contracted with phenylephrine relaxed due to the treatment of the LK fractions. These results suggest that the fibrinolytic effects of LK were mediated not only by proteolytic activity, but also by the inhibition of platelet agregation and the relaxation of blood vessels. It is concluded that the LK may be useful as a hemolytic agent for treatment of fibrin clot.
Extraction of Acanthoside-D from Acanthopanax Cortex using Supercritical Carbon Dioxide
KSBB Journal, volume 19, issue 4, 2004, Pages 284~287
The purpose of this study was to find an optimum extraction condition of acanthoside-D from acanthopanax cortex with supercritical carbon dioxide as a solvent. In this effort, effects of the extraction conditions including pressure, temperature and presence or absence of a cosolvent on the extraction efficiency were investigated. The ethanol, water or 50% methanol was used as a cosolvent whilst the operating pressure ranged from 200 bar to 300 bar. The acanthoside-D concentrations were determined by means of HPLC equipped with a UV detector. From the results, it was observed that increase of higher pressure led to the higher extraction efficiency. Further, water was found to be the best cosolvent among the entrainers tested.
200G on Yeast Cell Wall
KSBB Journal, volume 19, issue 4, 2004, Pages 288~290
The cell wall of fifteen yeast strains were treated with Glucanex
200G that contained mainly
1,3-glucanase and some
1,6-glucanase. In our previous study it was found that the yeasts that are more resistant to Glucanex
200G treatment contained more
-glucan than the yeasts that are less resistant to Glucanex
200G treatment. By measuring the resistance of cell wall to Glucanex
200G, the relative content of
-glucan in yeast cell wall could be estimated. The resistance of cell wall to Glucanex
200G was measured by counting viable cell number after reaction with and without Glucanex
200G. The resistance of fifteen yeast strains to Glucanex
200G were presented.ere presented.
Antibacterial Activity of Yeast Transformed with Leucocin A
KSBB Journal, volume 19, issue 4, 2004, Pages 291~294
The aim of this study was to figure out the antibacterial pattern of leucocin A transformed yeast with culture. Dry cell weight, total secreted protein, and antibacterial activity were increased to 12 hour, after then they showed decrease while protease activity represented the opposite pattern. This implied the production of leucocin A was growth-related. Compared to the result of one hour culture broth, antibacterial activity was about 3.24 fold at 12 hour culture. Maximum growth inhibition rate was 70.57% compared to nontransformed yeast. As the increase of protease in the supernatant, the antibacterial activity was diminished. This study could permit the mass production of bacteriocin to use as antibiotics or food preservatives.
The Optimal Culture Condition for the Collagenolytic Protease Production from Vibrio vulnificus CYK279H
KSBB Journal, volume 19, issue 4, 2004, Pages 295~300
A marine bacterium for producing an collagenolytic protease was isolated from the southern sea of Korea and identified as Vibrio vulnificus and named as Vibrio vulnificus CYK279H. This strain producing an collagenolytic protease was showed high activity toward collagen and gelatin as substrate. The optimum initial pH, NaCl, and temperature for cell growth and protease production was 7.5, 2.0% and 25
, respectively. Optimization for collagenolytic protease production was composed of 0.3% D-galactose, 0.6% yeast extract, 4.0% gelatin, 0.2% (NH
, and 0.2 mM ferric citrate in artificial sea water. The maximum protease production was required gelatin and yeast extract. The collagenolytic protease production by Vibrio vulnificus CYK279H reached a maximum of 73 unit/l after the cultivation for 18 h under the optimized medium.
Characteristics of a-Amylase of, a New Species, Aspergillus coreanus NR 15-1
KSBB Journal, volume 19, issue 4, 2004, Pages 301~307
The characteristics of the a-amylase of Aspergillus coreanus NR 15-1 isolated from traditional Korean Nuruk have been carried out. The a-amylase of A. coreanus NR 15-1 was purified by ammonium sulfate precipitation followed by column chromatographies on CM-cellulose, DEAE-cellulose, Sephadex G-100 gel filtration and hydroxyapatite. The a-amylase was purified 78-fold with a yield of 8.7%. The molecular weight of the a-amylase was estimated to be 49 kDa by Sephadex G-100 gel filtration and 51 kDa by SDS-polyacrylamide gel eletrophoresis. These experimental results suggested that the purified enzyme might be monomer. The enzyme was stable between pH 4 and 11. The optimum pH was 5.0. The optimum temperature for enzyme was 45
and the enzyme was stable up to 50
. The enzyme was significantly inhibited by 1 mM N-bromosuccinimide. These results suggested that tryptophan residue was involved in the active site of a-amylase. The enzyme was identified as a-amylase because the reaction products of soluble starch hydrolyzed by the purified enzyme was oligosaccharide by thin layer chromatography.
Isolation and Nucleotide Sequence Characterization of Novel Cytochrome P450 Hydroxylase Genes from Rare Actinomycetes, Sebekia benihana
KSBB Journal, volume 19, issue 4, 2004, Pages 308~314
A degenerate set of PCR primers based on two conserved regions (heme binding region and oxygen ligand pocket) were designed and successfully applied to amplify DNA fragments of cytochrome P450 hydroxylase (CYP) genes from a rare actinomycetes, S. benihana. The PCR amplified products were employed as a DNA probe to clone the entire CYP genes from S. benihana genomic library. Five different CYP-positive cosmids were isolated by colony hybridization as well as PCR confirmation. The complete nucleotide sequencing of five different CYP genes revealed that each unique CYP showed a significant amino acid homology to previously-known CYP genes involved in streptomycetes secondary metabolism. In addition, four CYP genes (CYP502, CYP503, CYP504, CYP506) were found to be linked to ferredoxin genes in the chromosome, and the CYP503 gene showed the high degree of amino acid similarity to the previously well-characterized CYP105 family in streptomycetes.
Isolation and Cultural Characteristics of Styrene Dimer [Endocrine Disrupter] Biodegrading Microorganism
KSBB Journal, volume 19, issue 4, 2004, Pages 315~320
We examined the culture conditions and degrading characteristics of styrene dimer (endocrine disrupter) using microorganism. The isolated microbe were consisted of 3 kinds of strain. The strains were identified to Pseudomonas sp. and Klebsiella pneumoniae by API 20E kit, but one was not identified. Single strain was not grown on the C-medium containing styrene dimer. However the complex strain YH3 could grow and we confirmed it by the broth color and O.D
(optical density 660 nm). The optimal culture conditions of complex strain YH3 were 35
, 1,000 ppm (v/v) of styrene dimer and pH 7.0, respectively. In tolerance test against the organic solvents, the complex strain YH3 could grow above log P=3.1, and could degrade ethyl benzene and 2,4-D, one kind of herbicide. As a result of TLC (Thin Layer Chromatography) analysis, we confirmed that the metabolite of styrene dimer was created by YH3 after 5th day, but not at control samples.
Preparation of Microparticulate Itraconazole/Hydroxypropyl-
-cyclodextrin Inclusion Complexes Using a Supercritical Anti-Solvent [SAS] Process
KSBB Journal, volume 19, issue 4, 2004, Pages 321~326
Microparticles of an inclusion complex between itraconazole and 2-hydroxypropyl-
-CD) were prepared using an environmentally-benign supercritical anti-solvent (SAS) process. In order to evaluate the degree of complexation, the thermal behavior of solid micro particulate complexes was investigated using differential scanning calorimetry. The experimental results obatined for the solubility and dissolution rate of the microparticulate inclusion complexes in a buffer solution of pH 1.2 showed that the complexation of itraconazole with HP-
-CD results in a significant increase in the solubility and dissolution rate of itraconazole. For the microparticulate itraconazole/Hp-
-CD inclusion complexes prepared by the SAS process, about 80% of itraconazole was found to dissolve in the buffer solution. Our experimental results confirmed that the SAS process is a promising method for the preparation of microparticles of water-insoluble drug/cyclodextrin inclusion complexes.
Production of Enantiomerically Pure [R]-3-Hydroxybutyric acid by Metabolically Engineered Escherichia coli with Inducible System
KSBB Journal, volume 19, issue 4, 2004, Pages 327~330
An inducible expression system of poly[(R)-3-hydroxybutyrate] (PHB) depolymerization was established in metabolically engineered Escherichia coli with the PHB biosynthesis genes. The Ralstonia eutropha PHB depolymerase gene was cloned in a vector system containing the PHB biosynthesis genes and expressed under inducible promoter. Recombinant E. coli harboring the PHB biosynthesis genes and depolymerase gene was first cultured for the accumulation of PHB, and then the depolymerase was expressed resulting in the degradation of accumulated PHB into (R)-3-hydroxybutyric acid (R3HB). R3HB could be produced with the concentration of 7.6 g/L in flask culture. Two different PHB biosynthesis genes from Alcaligenes latus and R. eutropha were compared for the production of R3HB. This strategy can be used for the production of enantiomerically pure (R)-hydroxycarboxylic acids with high concentration.
In Vivo Analysis of fadB Homologous Enzymes Involved in Biosynthesis of Polyhydroxyalkanoates in Recombinant Escherichia coli
KSBB Journal, volume 19, issue 4, 2004, Pages 331~334
In vivo characterization of FadB homologous enzymes including PaaG, YdbU and YgfG for medium-chain-length (MCL) polyhydroxyalkanoate (PHA) biosynthesis was carried out in fadB mutant Escherichia coli. Previously, it was reported that amplification of FadB homologous enzymes such as PaaG and YdbU in fadB mutant E. coli resulted in enhanced biosynthesis of MCL-PHA by greater than two fold compared with control strain. In this study, we constructed paaG fadB double mutant E. coli WB114 and ydbU fadB double mutant E. coli WB115 to investigate the roles of PaaG and YdbU in biosynthesis of MCL-PHA. Inactivation of paaG and ydbU genes in fadB mutant E. coli harboring Pseudomonas sp. 61-3 phaC2 gene reduced the MCL-PHA production to 0.16 and 0.16 PHA g/L, respectively from 2 g/L of sodium decanoate, which are much lower than 0.43 PHA g/L obtained with fadB mutant E. coli WB101 harboring the phaC2 gene. Also, we identified new FadB homologous enzyme YgfG, and examined its roles by overexpression of ygfG and construction of ygfG fadB double mutant E. coli WB113.