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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 17, Issue 12 - Dec 2007
Volume 17, Issue 11 - Nov 2007
Volume 17, Issue 10 - Oct 2007
Volume 17, Issue 9 - Sep 2007
Volume 17, Issue 8 - Aug 2007
Volume 17, Issue 7 - Jul 2007
Volume 17, Issue 6 - Jun 2007
Volume 17, Issue 5 - May 2007
Volume 17, Issue 4 - Apr 2007
Volume 17, Issue 3 - Mar 2007
Volume 17, Issue 2 - Feb 2007
Volume 17, Issue 1 - Jan 2007
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Discovery and Molecular Engineering of Sugar-containing Natural Product Biosynthetic Pathways in Actinomycetes
Oh, Tae-Jin ; Mo, Sang-Joon ; Yoon, Yeo-Joon ; Sohng, Jae-Kyung ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 1909~1921
Significant progress has recently been made concerning the engineering of deoxysugar biosynthesis. The biosynthetic gene clusters of several deoxysugars from various polyketides and aminoglycosides-producing microorganisms have been cloned and studied. This review introduces the biosynthetic pathways of several deoxysugars and the generation of novel hybrid macrolide antibiotics via the coexpression of deoxysugar biosynthetic gene cassettes and the substrate-flexible glycosyltransferases in a host organism as well as the production of TDP-deoxysugar derivatives via one-pot enzymatic reactions with the identified enzymes. These recent developments in the engineering of deoxysugars biosynthesis may pave the way to create novel secondary metabolites with potential biological activities.
Haematococcus pluvialis Cell-Mass Sensing Using Ultraviolet Fluorescence Spectroscopy
Lababpour, Abdolmajid ; Hong, Seong-Joo ; Lee, Choul-Gyun ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 1922~1929
A simple whole-cell-based sensing system is proposed for determining the cell mass of H. pluvialis using ultraviolet fluorescence spectroscopy. An emission signal at 368 nm was used to detect the various kinds of green, green-brown, brown-red, and red H. pluvialis cells. The fluorescence emission intensities of the cells were highest at 368 nm with an excitation wavelength of 227 nm. An excitation wavelength of 227 nm was then selected for cell-mass sensing, as the emission fluorescence intensities of the cell suspensions were highest at this wavelength after subtracting the background interference. The emission fluorescence intensities of HPLC-grade water, filtered water, and HPLC-grade water containing a modified Bold's basal medium (MBBM) were measured and the difference was less than 1.6 for the selected wavelengths. Moreover, there was no difference in the emission intensity at 368 nm among suspensions of the various morphological states of the cells. A calibration curve of the fluorescence emission intensities. and cell mass was obtained with a high correlation (
) for the various morphological forms of H. pluvialis. Accordingly, the proposed method showed no significant dependency on the various morphological cell forms, making it applicable for cell-mass measurement. A high correlation was found between the fluorescence emission intensities and the dry cell weight with a mixture of green, green-brown, brown-red, and red cells. In conclusion, the proposed model can be directly used for cell-mass sensing without any pretreatment and has potential use as a noninvasive method for the online determination of algal biomass.
Application of Factorial Experimental Designs for Optimization of Cyclosporin A Production by Tolypocladium inflatum in Submerged Culture
Abdel-Fattah, Y.R. ; Enshasy, H. El ; Anwar, M. ; Omar, H. ; Abolmagd, E. ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 1930~1936
A sequential optimization strategy based on statistical experimental designs was employed to enhance the production of cyclosporin A (CyA) by Tolypocladium inflatum DSMZ 915 in a submerged culture. A 2-level Plackett-Burman design was used to screen the bioprocess parameters significantly influencing CyA production. Among the 11 variables tested, sucrose, ammonium sulfate, and soluble starch were selected, owing to their significant positive effect on CyA production. A response surface methodology (RSM) involving a 3-level Box-Behnken design was adopted to acquire the best process conditions. Thus, a polynomial model was created to correlate the relationship between the three variables and the CyA yield, and the optimal combination of the major media constituents for cyclosporin A production, evaluated using the nonlinear optimization algorithm of EXCEL-Solver, was as follows (g/l): sucrose, 20; starch, 20; and ammonium sulfate, 10. The predicted optimum CyA yield was 113 mg/l, which was 2-fold the amount obtained with the basal medium. Experimental verification of the predicted model resulted in a CyA yield of 110 mg/l, representing 97% of the theoretically calculated yield.
Microbial Conversion of Ginsenoside
to Minor Ginsenoside
and Gypenoside XVII by Intrasporangium sp. GS603 Isolated from Soil
Cheng, Le-Qin ; Na, Ju-Ryun ; Kim, Myung-Kyum ; Bang, Myun-Ho ; Yang, Deok-Chun ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 1937~1943
A new strain, GS603, having
-glucosidase activity was isolated from soil of a ginseng field, and its ability to convert major ginsenoside
to minor ginsenoside or gypenoside was studied. Strain GS603 was identified as an Intrasporangium species by phylogenetic analysis and showed high ginsenoside-converting activity in LB and TSA broth but not in nutrient broth. The culture broth of the strain GS603 could convert ginsenoside
i into two metabolites, which were analyzed by TLC and HPLC and shown to be the minor ginsenoside
and gypenoside XVII by NMR.
Effects of Silkworm Hemolymph on Cell Viability and hCTLA4Ig Production in Transgenic Rice Cell Suspension Cultures
Cheon, Su-Hwan ; Lee, Kyoung-Hoon ; Kwon, Jun-Young ; Ryu, Hyun-Nam ; Yu, Da-Hyun ; Choi, Yong-Soo ; Kim, Dong-Il ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 1944~1948
Silkworm hemolymph (SH), prepared from fifth-instar larvae of Bombyx mori and heat-treated at
for 30 min, was used to improve cell viability and the production of human cytotoxic T-lymphocyte antigen 4-immunoglobulin (hCTLA4Ig) in transgenic Oryza sativa L. cell suspension cultures. Even though SH could not elevate cell viability at the concentrations up to 3% (v/v), addition of 0.3% (v/v) SH to a culture medium enhanced the production of hCTLA4Ig by 36.8% over an SH-free medium. Moreover, the production period of hCTLA4Ig could be shortened in a 0.3% (v/v) SH-added medium compared with that in an SH-free culture. As a result, addition of 0.3% (v/v) SH improved the productivity of hCTLA4Ig significantly in transgenic rice cell cultures.
Variations in Protein Glycosylation in Hansenula polymorpha Depending on Cell Culture Stage
Kim, So-Young ; Sohn, Jung-Hoon ; Pyun, Yu-Ryang ; Choi, Eui-Sung ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 1949~1954
A simple way to prevent protein hyperglycosylation in Hansenula polymorpha was found. When glucose oxidase from Aspergillus niger and carboxymethyl cellulase from Bacillus subtilis were expressed under the control of an inducible methanol oxidase (MOX) promoter using methanol as a carbon source, hyperglycosylated forms occurred. In contrast, MOX-repressing carbon sources (e.g., glucose, sorbitol, and glycerol) greatly reduced the extent of hyperglycosylation. Carbon source starvation of the cells also reduced the level of glycosylation, which was reversed to hyperglycosylation by the resumption of cell growth. It was concluded that the proteins expressed under actively growing conditions are produced as hyperglycosylated forms, whereas those under slow or nongrowing conditions are as short-glycosylated forms. The prevention of hyperglycosylation in the Hansenula polymorpha expression system constitutes an additional advantage over the traditional Saccharomyces cerevisiae system in recombinant production of glycosylated proteins.
Intracellular CD154 Expression Reflects Antigen-specific
Cells but Shows Less Sensitivity than Intracellular Cytokine and MHC Tetramer Staining
Han, Young-Woo ; Aleyas, Abi G. ; George, Junu A. ; Yoon, Hyun-A ; Lee, John-Hwa ; Kim, Byung-Sam ; Eo, Seong-Kug ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 1955~1964
A recent report showed that analysis of CD154 expression in the presence of the secretion inhibitor Brefeldin A (Bref A) could be used to assess the entire repertoire of antigen-specific
helper cells. However, the capacity of intracellular CD154 expression to identify antigen-specific
cells has yet to be investigated. In this study, we compared the ability of intracellular CD154 expression to assess antigen-specific
cells with that of accepted standard assays, namely intracellular cytokine IFN-
staining (ICS) and MHC class I tetramer staining. The detection of intracellular CD154 molecules in the presence of Bref A reflected the kinetic trend of antigen-specific
cell number, but unfortunately showed less sensitivity than ICS and tetramer staining. However, ICS levels peaked and saturated 8 h after antigenic stimulation in the presence of Bref A and then declined, whereas intracellular CD154 expression peaked by 8 h and maintained the saturated level up to 24 h post-stimulation. Moreover, intracellular CD154 expression in antigen-specific
cells developed in the absence of
cells changed little, whereas the number of IFN-
cells decreased abruptly. These results suggest that intracellular CD154 could aid the assessment of antigen-specific
cells, but does not have as much ability to identify heterogeneous
helper cells. Therefore, the combined analytical techniques of ICS and tetramer staining together with intracellular CD154 assays may be able to provide useful information on the accurate phenotype and functionality of antigen-specific
After-Rinsing Hair Growth Promotion of Minoxidil-containing Amino
Kim, Jin-Chul ; Kim, Myoung-Dong ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 1965~1969
-cyclodextrin (CD) was synthesized and the inclusion complex with Minoxidil (MXD) was prepared.
-CD was azidated by modifying the 6-hydroxylmethyl CD rim with sodium azide. Then, mono-, di-, tri-, and tetra-azidocyclodextrins were separated by a flash column chromatography and reduced to the corresponding amines by hydrogenation with Pd/C. The substantivities of MXD included in either 2-hydroxypropyl
-CD) or triamino
-CD were evaluated in vitro using hairless mice skins. After applying the preparations onto the skin and rinsing it, the amount of the drug left on the skin was determined using high-performance liquid chromatography (HPLC). It was the highest when the drug was included in triamino
-CD. The electrostatic interaction between the protonated amino CD and the negatively charged skin would be responsible for the relatively high substantivity. The in vivo hair growth promotion effect of each preparation was investigated, where the sample application onto the clipped backs of female mice (C57BL6) and the subsequent rinsing of the backs were done once a day for 30 days. Only MXD in triamino
-CD had hair growth promotion effect, possibly due to the significant substantivity.
Isolation and Structural Determination of Squalene Synthase Inhibitor from Prunus mume Fruit
Choi, Sung-Won ; Hur, Nam-Yoon ; Ahn, Soon-Cheol ; Kim, Dong-Seob ; Lee, Jae-Kwon ; Kim, Dae-Ok ; Park, Seung-Kook ; Kim, Byun-Yong ; Baik, Moo-Yeol ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 1970~1975
Squalene synthase plays an important role in the cholesterol biosynthetic pathway. Inhibiting this enzyme in hypercholesterolemia can lower not only plasma cholesterol but also plasma triglyceride levels. A squalene synthase inhibitor was screened from Prunus mume fruit, and then purified via sequential processes of ethanol extraction, HP-20 column chromatography, ethyl acetate extraction, silica gel column chromatography, and crystallization. The squalene synthase inhibitor was identified as chlorogenic acid with a molecular mass of 354 Da and a molecular formula of
based on UV spectrophotometry,
NMRs, and mass spectrometry. Chlorogenic acid inhibited the squalene synthase of pig liver with an
level of 100 nM. Since chlorogenic acid was an effective inhibitor against the squalene synthase of an animal source, it may be a potential therapeutic agent for hypercholesterolemia.
Thermophilic Biofiltration of Benzene and Toluene
Cho, Kyung-Suk ; Yoo, Sun-Kyung ; Ryu, Hee-Wook ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 1976~1982
In the current studies, we characterized the degradation of a hot mixture of benzene and toluene (BT) gases by a thermophilic biofilter using polyurethane as a packing material and high-temperature compost as a microbial source. We also examined the effect of supplementing the biofilter with yeast extract (YE). We found that YE substantially enhanced microbial activity in the thermophilic biofilter. The degrading activity of the biofilter supplied with YE was stable during long-term operation (approximately 100 d) without accumulating excess biomass. The maximum elimination capacity (
) in the biofilter supplemented with YE was 3.5 times higher than that in the biofilter without YE (
). At similar retention times, the capacity to eliminate BT for the YE-supplemented biofilter was higher than for previously reported mesophilic biofilters. Thus, thermophilic biofiltration can be used to degrade hydrophobic compounds such as a BT mixture. Finally, 168 rDNA polymerase chain reaction-DGGE (PCR-DGGE) fingerprinting revealed that the thermophilic bacteria in the biofilter included Rubrobacter sp. and Mycobacterium sp.
Supplementation of a Novel Microbial Biopolymer, PGB1, from New Enterobacter sp. BL-2 Delays the Deterioration of Type 2 Diabetic Mice
Yeo, Ji-Young ; Lee, Yong-Hyun ; Jeon, Seon-Min ; Jung, Un-Ju ; Lee, Mi-Kyung ; Jung, Young-Mi ; Choi, Myung-Sook ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 1983~1990
Antidiabetic effects of a novel microbial biopolymer (PGB) 1 excreted from new Enterobacter sp. BL-2 were tested in the db/db mice. The animals were divided into normal control, rosiglitazone (0.005%, wt/wt), low PGB1 (0.1%, wt/wt), and high PGB1 (0.25%, wt/wt) groups. After 5 weeks, the blood glucose levels of high PGB1 and rosiglitazone supplemented groups were significantly lower than those of the control group. In hepatic glucose metabolic enzyme activities, the glucokinase activities of PGB1 supplemented groups were significantly higher than the control group, whereas the PEPCK activities were significantly lower. The plasma insulin and hepatic glycogen levels of the low and high PGB1 supplemented groups were significantly higher compared with the control group. Specifically, the insulin and glycogen increases were dose-responsive to PGB1 supplement. PGB1 supplement did not affect the IPGTT and IPITT compared with the control group; however, rosiglitazone significantly improved IPITT. High PGB1 and rosiglitazone supplementation preserved the appearance of islets and insulin-positive cells in immunohistochemical photographs of the pancreas compared with the control group. These results demonstrated that high PGB1 (0.25% in the diet) supplementation seemingly contributes to preventing the onset and progression of type 2 diabetes by stimulating insulin secretion and enhancing the hepatic glucose metabolic enzyme activities.
O-Methylation of Flavonoids Using DnrK Based on Molecular Docking
Kim, Na-Yeon ; Kim, Jeong-Ho ; Lee, Youn-Ho ; Lee, Eun-Jung ; Kim, Jin-Young ; Lim, Yoong-Ho ; Chong, You-Hoon ; Ahn, Joong-Hoon ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 1991~1995
O-Methylation is a common substitution reaction found in microbes as well as in mammalians. Some of the O-methyltransferases (OMTs) have broad substrate specificity and could be used to methylate various compounds. DnrK from Streptomyces peucetius encodes an anthracycline 4-O-methyltransferase, which uses carminomycin as a substrate, and its crystal structure has been determined. Molecular docking experiments with DnrK using various flavonoids were successfully conducted, and some of the flavonoids such as apigenin and genistein were predicted to serve as substrates. Based on these results, O-methylations of various flavonoids with the DnrK were successfully carried out. The methylation position was determined to be at the hydroxyl group of C7. Important amino acid residues for the enzymatic reaction of DnrK with apigenin could be identified using site-directed mutagenesis. Molecular docking could be useful to predict the substrate specificity ranges of other OMTs.
Optimization of Culture Medium for Lactosucrose (
-D-Galactosylsucrose) Production by Sterigmatomyces elviae Mutant Using Statistical Analysis
Lee, Jong-Ho ; Lim, Jung-Soo ; Song, Yoon-Seok ; Kang, Seong-Woo ; Prak, Chul-Hwan ; Kim, Seung-Wook ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 1996~2004
In this study, the optimization of culture medium using a Sterigmatomyces elviae mutant was investigated using statistical analysis to increase the cell mass and lactosucrose (
-D-galactosylsucrose) production. In basal medium, the cell mass and lactosucrose production were 4.12 g/l and 140.91 g/l, respectively. However, because of the low cell mass and lactosucrose production, optimization of culture medium was carried out to increase the cell mass and lactosucrose production. Culture media were optimized by the S. elviae mutant using analysis of variance (ANOVA) and response surface methodology (RSM). Central composite designs using RSM were utilized in this investigation. Quadratic models were obtained for cell mass and lactosucrose production. In the case of cell mass, optimal components of the medium were as follows: sucrose 1.13%, yeast extract 0.99%, bactopeptone 2.96%, and ammonium sulfate 0.40%. The predicted maximum value of cell mass was about 5.20 g/l and its experimental value was 5.08 g/l. In the case of lactosucrose production, optimal components of the medium were as follows: sucrose 0.96%, yeast extract 1.2%, bactopeptone 3.0%, and ammonium sulfate 0.48%. Then, the predicted maximum value of lactosucrose production was about 194.12 g/l and the corresponding experimental value was about 183.78 g/l. Therefore, by culturing using predicted conditions, the real cell mass and lactosucrose production increased to 23.3% and 30.42%, respectively.
Differential Expression of Kidney Proteins in Streptozotocin-induced Diabetic Rats in Response to Hypoglycemic Fungal Polysaccharides
Hwang, Hye-Jin ; Baek, Yu-Mi ; Kim, Sang-Woo ; Kumar, G. Suresh ; Cho, Eun-Jae ; Oh, Jung-Young ; Yun, Jong-Won ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 2005~2017
Diabetic nephropathy remains a major cause of morbidity and mortality in the diabetic population and is the leading cause of end-stage renal failure. Despite current therapeutics including intensified glycemic control and blood pressure lowering agents, renal disease continues to progress relentlessly in diabetic patients, albeit at a lower rate. Since synthetic drugs for diabetes are known to have side effects, fungal mushrooms as a natural product come into preventing the development of diabetes. Our previous report showed the hypoglycemic effect of extracellular fungal polysaccharides (EPS) in streptozotocin (STZ)-induced diabetic rats. In this study, we analyzed the differential expression patterns of rat kidney proteins from normal, STZ-induced diabetic, and EPS-treated diabetic rats, to discover diabetes-associated proteins in rat kidney. The results of proteomic analysis revealed that up to 500 protein spots were visualized, of which 291 spots were differentially expressed in the three experimental groups. Eventually, 51 spots were statistically significant and were identified by peptide mass fingerprinting. Among the differentially expressed renal proteins, 10 were increased and 16 were decreased significantly in diabetic rat kidney. The levels of different proteins, altered after diabetes induction, were returned to approximately those of the healthy rats by EPS treatment. A histopathological examination showed that EPS administration restored the impaired kidney to almost normal architecture. The study of protein expression in the normal and diabetic kidney tissues enabled us to find several diabetic nephropathy-specific proteins, such as phospholipids scramblase 3 and tropomyosin 3, which have not been mentioned yet in connection with diabetes.
Swinging Effect of Salicylic Acid on the Accumulation of Polyhydroxyalkanoic Acid (PHA) in Pseudomonas aeruginosa BM114 Synthesizing Both MCL- and SCL-PHA
Rho, Jong-Kook ; Choi, Mun-Hwan ; Shim, Ji-Hoon ; Lee, So-Young ; Woo, Myeong-Ji ; Ko, Bong-Sung ; Chi, Ki-Whan ; Yoon, Sung-Chul ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 2018~2026
A bacterium, Pseudomonas aeruginosa BM114, capable of accumulating a blend of medium-chain-length (MCL)- and short-chain-length (SCL)-polyhydroxyalkanoic acid (PHA), was isolated. Salicylic acid (SA), without being metabolized, was found to specifically inhibit only the accumulation of MCL-PHA without affecting cell growth. An addition of 20 mM SA selectively inhibited the accumulation of MCL-PHA in decanoate-grown cells by 83% of the control content in one-step cultivation, where overall PHA accumulation was inhibited by only
. Typically, the molar monomer-unit ratio of the PHA for 25 mM decanoate-grown cells changed from 46:4:25:25 (=[3-hydroxybutyrate]:[3-hydroxycaproate]: [3-hydroxyoctanoate]:[3-hydroxydecanoate]) at 0 mM SA (dry cell wt, 1.97 g/l; PHA content, 48.6 wt%) to 91:1:4:4 at 20 mM SA (dry cell wt, 1.85 g/l; PHA content, 43.2 wt%). Thus, the stimulation of SCL-PHA accumulation was observed. Growth of P. aeruginosa BM114 on undecanoic acid also produced a PHA blend composed of 47.4% P(3HB-co-3-hydroxyvalerate) and 52.6% P(3-hydroxyheptanoate-co-3-hydroxynonanoate-co-3-hydroxyundecanoate). Similar to the case of even-carboxylic acids, SA inhibited the accumulation of only MCL-PHA, but stimulated the accumulation of SCL-PHA. For all medium-chain fatty acids tested, SA induced a stimulation of SCL-PHA accumulation in the BM114 strain. SA could thus be used to suppress only the formation of MCL-PHA in Pseudomonas spp. accumulating a blend of SCL-PHA and MCL-PHA.
Seed-dependent Accelerated Fibrillation of
-Synuclein Induced by Periodic Ultrasonication Treatment
Kim, Hyun-Jin ; Chatani, Eri ; Goto, Yuji ; Paik, Seung-R. ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 2027~2032
]-Synuclein is the major component of Lewy bodies and responsible for the amyloid deposits observed in Parkinson's disease. Ordered filamentous aggregate formation of the natively unfolded
-synuclein was investigated in vitro with the periodic ultrasonication. The ultrasonication induced the fibrillation of
-synuclein, as the random structure gradually converted into a
-sheet structure. The resulting fibrils obtained at the stationary phase appeared heterogeneous in their size distribution, with the average length and height of
, respectively. After additional extensive ultrasonication in the absence of monomeric
-synuclein, the equilibrium between the fibril formation and its breakdown shifted to the disintegration of the preexisting fibrils. The resulting fragments served as nucleation centers for the subsequent seed-dependent accelerated fibrillation under a quiescent incubation condition. This self-seeding amplification process depended on the seed formation and subsequent alterations in their properties by the ultrasonication to a state that accretes the monomeric soluble protein more effectively than their reassociation of the seeds back to the original fibrils. Since many neurodegenerative disorders have been considered to be propagated via the seed-dependent amyloidosis, this study would provide a novel aspect of the significance of the seed structure and its properties leading to the acce]erated amyloid formation.
Distinct Effect of Neurotrophins Delivered Simultaneously by an Adenoviral Vector on Neurite Outgrowth of Neural Precursor Cells from Different Regions of the Brain
Yoo, Min-Joo ; Joung, In-Sil ; Han, Ah-Mi ; Yoon, Hye-Hyun ; KimKwon, Yun-Hee ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 2033~2041
For many years, it has been demonstrated that neurotrophins regulate the adult nervous system, implicating their potential as therapeutic agents for the treatment of neurodegenerative diseases. We generated adenoviral vectors encoding brain-derived neutotrophin factor (BDNF) and neurotrophin-3 (NT3) and tested either separately or together for the ability to induce differentiation of neuronal precursor cells with two different origins. Separate transduction of adenovirus delivering BDNF (BDNF-Ad) or NT3 (NT3-Ad) induced the neuronal differentiation in hippocampal and cortical precursor cells. NT3-Ad infected cells extended short neurites, whereas BDNF-Ad infected cells had longer neurites. In the early differentiation of hippocampal precursor cells, simultaneous infection of BDNF-Ad and NT3-Ad promoted further differentiation and neurite elongation compared with the separate infection of each virus. In contrast, simultaneous infection did not show the synergistic effect in the cortical precursor cells, suggesting that the neurotrophins play distinct roles in different regions of the brain. However, the numbers of neurites and spines per differentiated cells were markedly increased in cortical as well as hippocampal precursor cells, indicating the promotion of efficient neurite elongation and formation of dendritic spine, when BDNF-Ad and NT3-Ad were co-infected. These results suggest more studies in the effect of a combinatorial use of neurotrophins on different sites of brain need to be carried out to develop gene therapy protocols for neurodegenerative diseases.
Inhibition of Proinflammatory Cytokine-induced Invasiveness of HT-29 Cells by Chitosan Oligosaccharide
Nam, Kyung-Soo ; Kim, Mee-Kyung ; Shon, Yun-Hee ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 2042~2045
The effect of chitosan oligosaccharide (COS, 1 kDa
, 10 ng/ml IL-
, and 25 ng/ml TNF-
) in HT-29 cells. Inducible nitric oxide synthase (iNOS) expression induced by these cytokines was inhibited by COS. COS pretreatment inhibited the invasiveness of cytokines-treated HT-29 cells through Matrigel-coated membrane in a dose-dependent manner. COS also inhibited cytokines-induced matrix metalloproteinase (MMP)-2 activity. This study shows that proinflammatory cytokines induce NO production, iNOS expression, and invasiveness of human colorectal adenocarcinoma HT-29 cells. COS pretreatment inhibited cytokines-mediated NO production, iNOS expression, and invasiveness of HT-29 cells. These results provide sufficient information for the further development of COS as an antitumor metastatic agent for the treatment of colon cancer.
Genetic Analysis of Spontaneous Lactose-Utilizing Mutants from Vibrio vulnificus
Baek, Chang-Ho ; Lee, Ko-Eun ; Park, Dae-Kyun ; Choi, Sang-Ho ; Kim, Kun-Soo ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 2046~2055
Wild-type V. vulnificus cannot grow using lactose as the sole carbon source or take up the sugar. However, prolonged culture of this species in media containing lactose as the sole carbon source leads to the generation of a spontaneous lactose-utilizing (LU) mutant. This mutant showed strong
-galactosidase activity, whereas the wild-type strain showed a barely detectable level of the activity. A mutant with a lesion in a gene homologous to the lacZ of E. coli in the bacterium no longer showed
-galactosidase activity or generated spontaneous LU mutants, suggesting that the lacZ homolog is responsible for the catabolism of lactose, but the expression of the gene and genes for transport of lactose is tightly regulated. Genetic analysis of spontaneous LU mutants showed that all the mutations occur in a lacI homolog, which is located downstream to the lacZ and putative ABC-type lac permease genes. Consistent with this, a genomic library clone containing the lad gene, when present in trans, made the spontaneous LU mutants no longer able to utilize lactose as the sole carbon source. Taken together with the observation that excessive amounts of exogenously supplemented possible catabolic products of lactose have negative effects on the growth and survivability of V. vulnificus, we suggest that V. vulnificus has evolved to carry a repressor that tightly regulates the expression of lacZ to keep the intracellular toxic catabolic intermediates at a sublethal level.
A Minor Transactivation Effect of GATA-3 on its Target Sites in the Extrachromosomal Status
Lee, Gap-Ryol ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 2056~2060
Transcription factor GATA-3 is the critical transcription factor for Th2 cell differentiation. In spite of its importance in Th2 cell differentiation, the molecular mechanism for its action in Th2 differentiation is poorly understood. Previous studies have suggested that GATA-3 may be involved in the chromatin remodeling in the Th2 cytokine locus. To determine whether GATA-3 exerts its effect on its target sites in the extrachromosomal status, cell transfection assay was performed. In this assay, 800 bp IL4 promoter-luciferase constructs linked with GATA-3 target sites were transfected into the M12 B cell line, D10 mouse Th2 cell lines, and human T lymphoma Jurkat cell lines with or without the GATA-3 expression vector. The GATA-3 effects on its target sites were minimal in the extrachromosomal status, supporting the previous propositions that GATA-3 functions at the chromatin level by remodeling chromatin structure.
Chemical Composition and Antibacterial Activity of Essential Oil from Artemisia feddei
Cha, Jeong-Dan ; Jung, Eun-Kyung ; Kil, Bong-Seop ; Lee, Kyung-Yeol ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 2061~2065
The chemical components of the essential oil from Artemisia feddei LEV et VNT. were analyzed using GC-MS. Ninety-nine compounds, accounting for 96.23% of the extracted essential oil, were identified. The main oil compounds were 1,8-cineole (16.86%), chamazulene (9.04%),
-terpinyl acetate (5.07%), borneol (5.08%),
-caryophyllene (4.71%), camphor (4.04%), and terpinen-4-ol (3.04%). The antimicrobial activity of the essential oil and some of its compounds was tested against 15 different genera of oral bacteria. The essential oil from A. feddei had a considerable inhibitory effect on all the obligate anaerobic bacteria tested (MICs, 0.025 to 0.05 mg/ml; MBCs, 0.025 to 0.1 mg/ml), whereas the major compounds demonstrated different degrees of growth inhibition.
Overexpression of Shinorhizobium meliloti Hemoprotein in Streptomyces lividans to Enhance Secondary Metabolite Production
Kim, Yoon-Jung ; Sa, Soon-Ok ; Chang, Yong-Keun ; Hong, Soon-Kwang ; Hong, Young-Soo ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 2066~2070
It was found that Shinorhizobium meliloti hemoprotein (SM) was more effective than Vitreoscilla hemoglobin (Vhb) in promoting secondary metabolites production when overexpressed in Streptomyces lividans TK24. The transformant with sm (sm-transformant) produced 2.7-times and 3-times larger amounts of actinorhodin than the vhb-transformant in solid culture and flask culture, respectively. In both solid and flask cultures, a larger amount of undecylprodigiocin was produced by the sm-transformant. It is considered that the overexpression of SM especially has activated the pentose phosphate pathway through oxidative stress, as evidenced by an increased NADPH production observed, and that it has promoted secondary metabolites biosynthesis.
Antifungal Activities of Bacillus thuringiensis Isolates on Barley and Cucumber Powdery Mildews
Choi, Gyung-Ja ; Kim, Jin-Cheol ; Jang, Kyoung-Soo ; Lee, Dong-Hyung ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 2071~2075
Fourteen Bacillus thuringiensis isolates having both insecticidal activity and in vitro antifungal activity were selected and tested for in vivo antifungal activity against tomato late blight, wheat leaf rust, tomato gray mold, and barley powdery mildew in growth chambers. All the isolates represented more than 70% disease control efficacy against at least one of four plant diseases. Specifically, 12 isolates exhibited strong control activity against barley powdery mildew. Under glasshouse conditions, four (50-02, 52-08, 52-16, and 52-18) of the isolates also displayed potent control efficacy against cucumber powdery mildew. To our knowledge, this is the first report of B. thuringiensis isolates that have disease control efficacy against powdery mildew of barley and cucumber as well as insecticidal activity.
Constitutive Coexpression of Bacillus Endoxylanase and Trichoderma Endoglucanase Genes in Saccharomyces cerevisiae
Lee, Jae-Hyung ; Lim, Myung-Ye ; Kim, Mi-Jin ; Heo, Sun-Yeon ; Seo, Jin-Ho ; Kim, Yeon-Hee ; Nam, Soo-Wan ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 2076~2080
The endoxylanase (GenBank Access No. U51675) of Bacillus spp. and endoglucanase (GenBank Access No. AY466436) of Trichoderma spp. were separately inserted downstream of the yeast constitutive ADHI promoter, resulting in three different plasmids (pAGX1, pAGX2, and pAGX3) according to the transcription direction of two genes. When the yeast transformants, S. cerevisiae SEY2102 harboring each expression plasmid, were grown on YPD medium, the total activities of the enzymes were approximately 3.01 unit/ml, 3.24 unit/ml, and 7.56 unit/ml for endoxylanase and 0.60 unit/ml, 0.54 unit/ml, and 0.39 unit/ ml for endoglucanase, in the following order: the pAGX1, pAGX2, and pAGX3. More than 70% of the endoxylanase and endoglucanase activities was found in the extracellular media.
-Galactosidase Gene from Leuconostoc mesenteroides SY1 in Leuconostoc citreum
Park, Jae-Yong ; Jeong, Seon-Ju ; Lee, Ae-Ran ; Park, Ji-Yeong ; Jeong, Woo-Ju ; Kim, Jeong-Hwan ;
Journal of Microbiology and Biotechnology, volume 17, issue 12, 2007, Pages 2081~2084
A 2.5 kb aga gene encoding
-Gal) from Leuconostoc mesenteroides SY1 was cloned into pSJE, an E. coli-Leuconostoc shuttle vector. The recombinant plasmid, pSJEaga, was introduced into Leuconostoc citreum KCTC3526 (ATCC49370) by electroporation. Transcription level of aga was the highest in cells grown on raffinose (1%, w/v) followed by cells grown on galactose, melibiose, fructose, glucose, and sucrose. Western blot using antibodies against
-Gal showed similar results to slot-blot results and enzyme activity measurements. All the results indicated that the aga was successfully expressed in L. citreum and its transcription was under the carbon catabolite repression (CCR).