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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Microbiology and Biotechnology
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Journal DOI :
The Korean Society for Applied Microbiology and Biotechnology
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Volume & Issues
Volume 9, Issue 6 - Dec 1999
Volume 9, Issue 5 - Oct 1999
Volume 9, Issue 4 - Aug 1999
Volume 9, Issue 3 - Jun 1999
Volume 9, Issue 2 - Apr 1999
Volume 9, Issue 1 - Feb 1999
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Direct Electrode Reaction of Fe(III)-Reducing Bacterium, Shewanella putrefaciens
Kim, Byung-Hong ; Kim, Hyung-Joo ; Hyun, Moon-Sik ; Park, Doo-Hyun ;
Journal of Microbiology and Biotechnology, volume 9, issue 2, 1999, Pages 127~131
Anaerobically grown cells of an Fe(III)-reducing bacterium, Shewanella putrefaciens IR-l, were electrochemically active with an apparent reduction potential of about 0.15 V against a saturated calomel electrode in the cyclic voltammetry. The bacterium did not grow fermentatively on lactate, but grew in an anode compartment of a three-electrode electrochemical cell using lactate as an electron donor and the electrode as the electron acceptor. This property was shared by a large number of Fe(III)-reducing bacterial isolates. This is the first observation of a direct electrochemical reaction by an intact bacterial cell, which is believed to be possible due to the electron carrier(s) located at the cell surface involved in the reduction of the natural water insoluble electron acceptor, Fe(III).
Improvement of Bifidobacterium longum Stability Using Cell-Entrapment Technique
Woo, Chang-Jae ; Lee, Ki-Yong ; Heo, Tae-Ryeon ;
Journal of Microbiology and Biotechnology, volume 9, issue 2, 1999, Pages 132~139
A cell-entrapment technique using compressed air was applied to Bifidobacterium longum KCTC 3128 for the improvement of bifidobacteria viability. The main cell-entrapment matrix used was alginate, and viability improvement of the B. longum entrapped in alginate lattices was monitored along with the effects of other additional biopolymers. A prerequisite for acquiring consistent results was the uniformity of bead size and cell distribution which was achieved by using compressed air and mixing the cell suspension with sterilized alginate powder, respectively. The viability losses of the B. longum entrapped in alginate beads in the presence of three different substances logarithmically increased in relation to the reaction time, and proportionately decreased with an increased alginate concentration and bead diameter. The strongest improvement in B. longum viability was exhibited with a bead containing 3％ alginate and 0.15％ xanthan gum.
Maximization of Poly-
-Hydroxybutyrate Accumulation by Potassium Limitation in Methylobacterium organophilum and Its Related Metabolic Analysis
Kim, Seon-Won ; Kim, Pil ; Kim, Jung-Hoe ;
Journal of Microbiology and Biotechnology, volume 9, issue 2, 1999, Pages 140~146
When methanol was the sole carbon source, Methylobacterium organophilum NCIB 11278, a facultative methylotroph, accumulated Poly-
-hydroxybutyrate (PHB) as 59% (w/w) of dry cell weight under potassium limitation, 37% under sulfate limitation, and 33% under nitrogen limitation. Based on a stoichiometric analysis of PHB synthesis from methanol, it was suspected that PHB synthesis is accompanied by the overproduction of energy, either 6-10 ATP and 1
or 6 ATP and 3 NADPH to balance the NADH requirement, per PHB monomer. This was confirmed by observation of increased intracellular ATP levels during PHB accumulation. The intracellular ATP with limited potassium, sulfate, and ammonium increased to 0.185, 0.452, and 0.390
moles ATP/g Xr (residual cell mass) during PHB accumulation, respectively. The intracellular ATP level under potassium limitation was similar to that when there was no nutrient limitation and no PHB accumulation, 0.152- 0.186
moles ATP/g Xr. We propose that the maximum PHB accumulation observed when potassium was limited is a result of the energy balance during PHB accumulation. Microorganisms have high energy requirements under potassium limitation. Enhanced PHB accumulation, in ammonium and sulfate limited conditions with the addition of 2,4-dinitrophenol, which dissipates surplus energy, proves this assumption. With the addition of 1 mM of 2,4-dinitrophenol, the PHB content increased from 32.4% to 58.5% of dry cell weight when nitrogen limited and from 15.1 % to 31.0% of dry cell weight when sulfate limited.
Involvement of Cytochrome P450 in (-)-(4R)-Isopiperitenone Oxidation by Cell Suspension Cultures of Mentha piperita
Park, Si-Hyung ; Chang, Yung-Jin ; Kim, Kyung-Hyun ; Kim, Soo-Un ;
Journal of Microbiology and Biotechnology, volume 9, issue 2, 1999, Pages 147~149
Biotransformation of exogenous (-)-(4R)-isopiperitenone in cell suspension cultures of Mentha piperita resulted in oxidized products, with (-)-7-hydroxyisopiperitenone being the major compound. The mass of products obtained
, atmosphere was two units higher than that under normal atmosphere. The biotransformation was inhibited by several cytochrome P450-specific inhibitors as well as by carbon monoxide. Carbon monooxide inhibition was substantially overcome by irradiation of cells with blue light including light at 450nm wavelength. These results suggested that a cytochrome P450-type monooxygenase was involved in the biotransformation.
The Effects of Fetal Bovine Serum, Epidermal Growth Factor, and Retinoic Acid on Adult Rat Islets Embedded in Collagen Gels
Shin, Jun-Seop ; Chang, Hyo-Ihl ; Sung, Ha-Chin ; Kim, Chan-Wha ;
Journal of Microbiology and Biotechnology, volume 9, issue 2, 1999, Pages 150~156
The induction of proliferation of adult rat islets was investigated under various culture conditions. The islets were isolated from male Sprague-Dawley rats and subsequently embedded in collagen gels, which mimic the in vivo three-dimensional surroundings. During the culture period, the effects of heterologous serum (fetal bovine serum, FBS), epidermal growth factor (EGF), and retinoic acid (RA) on islet growth were examined with respect to the morphological and total DNA content changes. To investigate these changes at the cellular level, whole mount immunocytochemistry using specific antibodies for insulin and glucagon was performed. The results showed that (i) collagen gels as an extracellular matrix can maintain islets in a similar way to that in vivo, (ii) heterologous serum (FBS) had stimulatory effects on islet proliferation in a dose-dependent manner, (iii) RA had inhibitory effects on islet proliferation induced by the serum in a dose-dependent manner, (iv) EGF had weak inhibitory effects on islet proliferation induced by the serum except at the concentration of 10 nM where its effect was not significant, and (v) whole mount immunocytochemistry revealed that newly proliferated islet cells were mainly
Characterization of Xylanase Produced by Bacillus pumilus Strain PJ19
Hamzah, Ainon ; Abdulrashid, Nooraini ;
Journal of Microbiology and Biotechnology, volume 9, issue 2, 1999, Pages 157~162
Bacillus pumilus PJ19 isolated from Pinus leaves showed optimum xylanase production when grown in yeast tryptone broth at
, pH 7.2, and shaken at 200 rpm after 48 h of incubation. Xylanase production was induced by xylan and xylose but repressed in the presence of glucose. Xylanase production by B. pumilus PJ19 was not growth-associated and the maximum enzyme production was found after 36 h of incubation.
Characterization of an Acidic Polysaccharide from Fruiting Bodies of Lyophyllum shimeji
Lee, Jae-Hoon ; Cho, Soo-Muk ; Han, Sang-Bae ; Kim, Hwan-Mook ; Yoo, Ick-Dong ;
Journal of Microbiology and Biotechnology, volume 9, issue 2, 1999, Pages 163~167
An acidic polysaccharide H-III was extracted from fruiting bodies of Lyophyllum shimeji with hot water. Acid hydrolysis and gas chromatography analysis showed that the polysaccharide was almost exclusively composed of glucose with a very small amount of mannose and galactose. Uronic acid of 8.36% was also detected in H-Ill. Its molecular weight was estimated to be
analysis, some repeating units of disaccharide were detected in the polymer H-III. The polysaccharide showed a strong mitogenic activity in a dose-dependent manner.
Antifungal Mechanism of Antifungal Peptide Derived from Cecropin A(1-8)- Melittin(1-12) Hybrid against Aspergillus fumigatus
Lee, Dong-Gun ; Jin, Zhe-Zhu ; Maeng, Cheol-Young ; Shin, Song-Yub ; Seo, Moo-Yeol ; Kim, Kil-Lyong ; Hahm, Kyung-Soo ;
Journal of Microbiology and Biotechnology, volume 9, issue 2, 1999, Pages 168~172
The antifungal mechanism of the antifungal peptide against Aspergillus fumigatus,
-CA(l-8)-ME(l-12), derived from cecropin A(l-8)-melittin(l-12) was investigated by confocal laser scanning microscopy, cell wall regeneration, ATPase activity inhibition, and released potassium ion. By confocal laser scanning microscopy,
-CA(l-8)-ME(l-12) was detected on the surface of A. fumigatus, while cecropin A used as a negative control peptide was not detected. The protoplast of A. fumigatus treated with
-CA(1-8)-ME(1-12) failed to regenerate the fungal cell walls. Compared with cecropin A, the amount of potassium ion released by
-CA(l-8)-ME(l-12) was increased. Furthermore,
-CA(l-8)-ME(l-12) inhibited the ATPase activity on the plasma membrane. These results suggested that
-CA(l-8)-ME(1-12) acts on the plasma membrane of A. fumigatus and its antifungal action is due to the ion channel or pore formation on the plasma membrane.
Purification and Properties of Extracellular Cytosine Deaminase from Chromobacterium violaceum YK 391
Yu, Tae-Shick ; Kim, Tae-Hyun ;
Journal of Microbiology and Biotechnology, volume 9, issue 2, 1999, Pages 173~178
The extracellular cytosine deaminase (EC 188.8.131.52) from Chromobacterium violaceum YK 391 was purified 264.7-fold with an overall yield of 14.3%. The enzyme was for the first time homogeneous by the criteria of polyacrylamide gel electrophoresis performed in the absence and in the presence of sodium dodecyl sulfate. The molecular weight of the purified enzyme was estimated to be about 156 kDa. The enzyme consisted of two identical subunits of approximate molecular weight 78 kDa. The isoelectric point of the enzyme was pH 5.55. The enzyme had a pH optimum of 7.5 and a temperature optimum of around 40 to
. Besides cytosine, the enzyme deaminated 5-fluorocytosine, cytidine, 5-methylcytosine, and 6-azacytosine, but not 5-azacytosine. The extracellular cytosine deaminase is believed to be unique because it was active not only on cytosine but also on cytidine. The apparent
values for cytosine, 5-fluorocytosine, cytidine, and 5-methylcytosine were determined to be 1.55 mM, 5.52 mM, 10.4 mM, and 67.2 mM, respectively. The enzyme activity was strongly inhibited by heavy metal ions such as
at 1 mM, and completely by
-chloromercuribenzoate at 1 mM, and weakly inhibited by 1mM ο-phenanthroline. The enzyme activity was not affected by various nucleosides and nucleotides.
Downstream Processing of Recombinant Hirudin Produced in Saccharomyces cerevisiae
Chung, Bong-Hyun ; Kim, Won-Kyung ; Rao, K.Jagannadha ; Kim, Chul-Ho ; Rhee, Sang-Ki ;
Journal of Microbiology and Biotechnology, volume 9, issue 2, 1999, Pages 179~183
A recombinant form of hirudin, a potent thrombin-specific inhibitor derived from the bloodsucking leech, was expressed as a secretory product in Saccharomyces cerevisiae under the control of GALl0 promoter and the mating factor
pre-pro leader sequence. In an attempt to produce recombinant hirudin (r-Hir) of therapeutic purity in large quantities, the fed-batch fermentation was carried out by using this recombinant yeast, and subsequently downstream processing was developed with the preparative-scale column chromatography systems. About 234 mg/l of biologically active r-Hir was produced as a secretory product by the fed-batch fermentation strategy developed for an efficient downstream processing. Using a two-step chromatography process (an anion exchange chromatography followed by the reverse phase HPLC), the r-Hir was purified to>98% with an overall recovery yield of 84%. According to the N-terminal amino acid sequencing, the purified r-Hir was found to have the predicted N-terminal amino acid sequence. The biological activity of the purified r-Hir to inhibit thrombin was also identical to that of the commercial hirudin.
Specific Detection of Enteropathogen Campylobacter jejuni in Food Using a Polymerase Chain Reaction
Shin, Soon-Young ; Park, Jong-Hyun ; Kim, Wang-June ;
Journal of Microbiology and Biotechnology, volume 9, issue 2, 1999, Pages 184~190
The use of the polymerase chain reaction (PCR) method was described using two sets of primers based on the ceuN gene (JEJ 1 and JEJ 2) which encodes a protein involved in siderophore transport and 16S rRNA gene (pA and pB) for the sensitive and specific detection of enteropathogen Campylobacter jejuni. Six oligonucleotides were utilized in an amplification experiment and PCR products of predicted sizes were generated from whole cells and boiled cell lysates at the same intensity. Two sets of the primer pairs, JEJ and pAB, were specific enough for all C. jejuni strains tested for the direct use of whole cells without DNA extraction or lysis steps. In the PCR using the pAB primer pair, the detection limit, as determined by the ethidium bromide staining of the amplification products on agarose gels, was at the level of
bacteria cells or less in both the pure culture and artificially inoculated milk and chicken enrichment samples, whereas the detection limit with the JEJ primer pair was relatively low, i.e.
cells or more in the same PCR samples. The PCR method using either a primer JEJ or pAB was both repeatable and specific for the detection of C. jejuni in food. This method is simply completed within 4 h.
Enhancement of Succinate Production by Organic Solvents, Detergents, and Vegetable Oils
Kang, Kui-Hyun ; Ryu, Hwa-Won ;
Journal of Microbiology and Biotechnology, volume 9, issue 2, 1999, Pages 191~195
Bioconversion of fumarate to succinate by Enterococcus sp. RKY1 was enhanced when Tween surfactant, organic solvent, and vegetable oil were added to the fermentation medium. The maximum amount of succinate produced was 80.4 g/l after a 24 h incubation when Tween 80 was added to the culture to a final concentration of 0.1 g/l. Triton X-l00 was observed to damage the enzymes and inhibit the formation of succinate. The addition of 10 ml/l acetone increased the production of succinate by 110%. Vegetable oils used were found to be effective for succinate production as well as for the cell growth. Similar productivity increases were obtained with corn oil and Tween 80 plus biotin with the total productivity being 3.6 g/l/h, and 3.5 g/l/h, respectively, which was approximately 25% greater than that of the control. Therefore, these results indicate that com oil can be considered the most appropriate agent for the production of succinate where succinic acid was primarily used in the production of food, medicine, and cosmetics.
Secretory Expression of Human
-Casein in Saccharomyces cerevisiae
Kim, Yoo-Kyeong ; Yu, Dae-Yeul ; Kang, Hyun-Ah ; Yoon, Sun ; Chung, Bong-Hyun ;
Journal of Microbiology and Biotechnology, volume 9, issue 2, 1999, Pages 196~200
A recombinant human
-casein was expressed as a secretory product in the yeast Saccharomyces cerevisiae. Three different leader sequences derived from the mating factor
l), inulinase, and human
-casein were used to direct the secretion of human
-casein into the extracellular medium. Among the three leader sequences tested, the native leader sequence of human
-casein was found to be the most efficient in the secretory expression of human
-casein, which implies that the native leader sequence of human
-casein might be used very efficiently for the secretory production of other heterologous proteins in yeast. The recombinant human
-casein was proteolytically cleaved as the culture proceeded. Therefore, an attempt was made to produce human
-casein using a S. cerevisiae mutant in which the YAP3 gene encoding yeast aspartic protease 3 (YAP3) was disrupted. After 72 h of culture, most of the human
-casein secreted by the wild type was cleaved, whereas more than 70% of the human
-casein secreted by yap3-disruptant remained intact. The results suggest that YAP3 might be involved in the internal cleavage of human
-casein expressed in yeast
Effect of Temperature and Carbon Source on the Expression of
-Galactosidase Gene of Lactococcus lactis ssp. lactis ATCC 7962
Kim, Tea-Youn ; Lee, Jung-Min ; Chang, Hae-Choon ; Chung, Dae-Kyun ; Lee, Jong-Hoon ; Kim, Jeong-Hwan ; Lee, Hyong-Joo ;
Journal of Microbiology and Biotechnology, volume 9, issue 2, 1999, Pages 201~205
The effects of growth temperature and a carbon source on the expression of
-galactosidase gene of Lactococcus lactis ssp. lactis ATCC 7962 (L. lactis 7962) were investigated. At
, L. lactis 7962 had a higher
-galactosidase activity than cells grown at
, although cells grew most quickly at
-galactosidase activity was observed in cells grown in M17 with lactose (l %) followed by cells grown in a galactose (1 %) medium. L. lactis 7962 exhibited the minimum
-galactosidase activity in glucose media, indicating catabolite repression. When the cellular levels of
-galactosidase mRNA were examined using slot blot hybridization, no significant differences were observed between cells grown at
and cells at
in the same media. This suggests that the quantity of
-galactosidase mRNA may not be the reason for the higher
-galactosidase activities of L. lactis 7962 at
The level of ccpA (Catabolite Control Protein) transcript remained almost constant during the exponential growth phase irrespective of a carbon sourse.
Expression of orf7(oxi III) as dTDP-Glucose 4,6-Dehydratase Gene Cloned from Streptomyces antibioticus Tu99 and Biochemical Characteristics of Expressed Protein
Yoo, Jin-Cheol ; Han, Ji-Man ; Sohng, Jae-Kyung ;
Journal of Microbiology and Biotechnology, volume 9, issue 2, 1999, Pages 206~212
The gene orf7(oxi III) was expressed using an E. coli system in anticipation that it would encode dTDP-glucose 4,6-dehydratase which is involved in the biosynthesis of the olivose moiety of chlorothricin produced from Streptomyces antibioticus Tu99. The solubility of the expressed protein increased up to 20% under optimal induction conditions. The expressed protein was purified from the E. coli BL 21(DE3) cell lysate by a 28.5-fold purification in two chromatography steps with a 38% recovery to near homogeneity. The molecular weight and N-terminal amino acid sequence of the purified protein correlated with the predicted mass and sequence deduced from the orf7 gene. The purified protein was a homodimer with a subunit relative molecular weight of 38,000 Dalton. The expressed protein was found to exhibit dTDP-glucose 4,6-dehydratase activity and be highly specific for dTDP-glucose as a substrate. The values of K'm and V'max for dTDP-glucose were 28
M and 295 nmol
, respectively. dTTP and dTDP were strong inhibitors of this enzyme.
, the coenzyme for dTDP-glucose 4,6-dehydratase, was tightly bound to the expressed protein.
Transgenic Tobacco Plants Expressing the Bacterial Levansucrase Gene Show Enhanced Tolerance to Osmotic Stress
Park, Jeong-Mee ; Kwon, Suk-Yoon ; Song, Ki-Bang ; Kwak, Ju-Won ; Lee, Suk-Bae ; Nam, Young-Woo ; Shin, Jeong-Sheop ; Park, Young-In ; Rhee, Sang-Ki ; Paek, Kyung-Hee ;
Journal of Microbiology and Biotechnology, volume 9, issue 2, 1999, Pages 213~218
Fructans are polyfructose molecules that function as nonstructural storage carbohydrates in several plants. In addition, it has been suggested that, due to their solubility, they can play an important role in helping plants survive periods of osmotic stress. In order to study the effect of levan synthesis on plant growth, the coding region of the levansucrase gene, which was isolated from Zymomonas mobilis, was introduced into tobacco plants using Agrobacterium tumefaciens-mediated transformation. The presence of the levansucrase gene in transgenic plants was verified by genomic DNA gel blot analysis. RNA gel blot and immunoblot analyses showed an accumulation of the corresponding transcript and protein product of the bacterial levansucrase gene in transgenic plants. Furthermore, a thin layer chromatography analysis revealed that fructans were synthesized and deposited in transgenic tobacco plants. When
seeds were germinated and grown under polyethylene glycol-mediated drought stress or cold stress, the transgenic seedlings displayed a substantially higher level of growth than that of untransformed plants. These results suggest that fructans may playa significant role in the tolerance of plants under osmotic stress.
Facile Purification and Characterization of Dextransucrase from Leuconostoc mesenteroides B-512FMCM
Kim, Do-Man ; Kim, Do-Won ;
Journal of Microbiology and Biotechnology, volume 9, issue 2, 1999, Pages 219~222
A simple sequence of membrane concentration and DEAE-Cellulose chromatography has been optimized to give a purified dextransucrase from Leuconostoc mesenteroides B-512FMCM with the highest specific activity (248.8 IU/mg protein) ever reported in high yield (overall 88.7%) for dextransucrase. When there was no sucrose in the dextransucrase and the dextran reaction digest, the dextransucrase hydrolyzed glucose from dextran. The glucose was transferred to the other glucoses from dextran and formed isomaltose and isomaltodextrin. The transglycosylation efficiency of glucose from dextran was much higher with acceptors. The dextransucrase can be used for the production of various kinds (or structures) of oligosaccharides using dextran and various acceptors with almost 100% theoretical yield.
Isolation of a Phytase-Producing Bacillus sp. KHU-10 and Its Phytase Production
Choi, Yang-Mun ; Noh, Dong-Ouk ; Cho, Sung-Ho ; Lee, Hyo-Ku ; Suh, Hyung-Joo ; Chung, Soo-Hyun ;
Journal of Microbiology and Biotechnology, volume 9, issue 2, 1999, Pages 223~226
A bacterial strain producing high level of an extracellular phytase was isolated from cooked rice and identified as a strain of Bacillus sp. and designated as Bacillus sp. KHU-10. Optimum culture conditions were investigated for the maximum productivity of phytase by Bacillus sp. KHU-10. 1.0% Maltose and 1.0% peptone with 0.5% beef extract were the best carbon source and nitrogen source, respectively. The addition of
, stimulated the enzyme productivity with concentration between 0.01% and 0.2%, in the medium. Although sodium phosphate increased the cell mass, the enzyme activity decreased. Calcium phytate and wheat bran containing phytate did not enhance the enzyme production. Under the optimum medium, the production of the phytase reached the highest level of 0.2 unit/ml after 4 days of incubation.
Reduction of FBS Concentration through Adaptation Process in Mammalian Cell Culture and Addition of Silkworm Hemolymph in Insect Cell Culture
Kim, Eun-Jeong ; Park, Tai-Hyun ;
Journal of Microbiology and Biotechnology, volume 9, issue 2, 1999, Pages 227~229
Animal cell culture media are usually supplemented with fetal bovine serum (FBS); however, the use of FBS presents certain problems including high cost. By using an adaptation process and the addition of silkworm hemolymph, the FBS concentration can be reduced without causing a significant decrease in cell growth.
Expression of Bacillus macerans Cyclodextrin Glucanotransferase in Bacillus subtilis
Kim, Chang-Sup ; Han, Nam-Soo ; Kweon, Dae-Hyuk ; Seo, Jin-Ho ;
Journal of Microbiology and Biotechnology, volume 9, issue 2, 1999, Pages 230~233
A plasmid vector was constructed for the expression and secretion of Bacillus macerans cyclodextrin glucanotransferase (CGTase) in Bacillus subtilis. The vector, pUBACGT, was composed of the ribosome-binding sequence, signal sequence, and cgt gene from B. macerans under the control of amyR2, the promoter of amyE gene coding for
-amylase from B. subtilis var. natto. Bacillus subtilis LKS88, a mutant strain lacking genes for an amylase and two proteases, was used as a host for the transformation of the plasmid vector. The transformants were selected on kanamycin-containing Luria-Bertani plates. The starch hydrolyzing activity was observed on the starch-containing plates by the iodine method and cyclodextrin-forming activity was detected in the culture medium. A SDS-PAGE analysis showed that most of the expressed CGTase in the recombinant B. subtilis was secreted into the medium at a high expression level.