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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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The Korean Society for Applied Microbiology and Biotechnology
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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
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Burkholderia Diversity and Versatility: An Inventory of the Extracellular Products
Vial, Ludovic ; Groleau, Marie-Christine ; Dekimpe, Valerie ; Deziel, Eric ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1407~1429
The Burkholderia genus consists of over 40 Gram-negative,
-proteobacteria species that occupy remarkably diverse ecological niches. This genus contains species pathogenic to human, animals, and plants, as well as species involved in promoting plant growth and biodegradation of pollutants. This is largely explained by the extraordinary versatility of Burkholderia, as reflected by the remarkable diversity of extracellular products released by these bacteria. We exhaustively surveyed the extracellular enzymes, siderophores, toxins, antimicrobials, and other secondary metabolites produced by the members of this very diverse genus. Available information on regulation, especially quorum sensing mechanisms, and secretion is highlighted.
Degradation of Raffinose Oligosaccharides in Soymilk by Immobilized
-Galactosidase of Aspergillus oryzae
Kotiguda, Girigowda ; Kapnoor, Shankar S. ; Kulkarni, Dhananjay ; Mulimani, Veerappa H. ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1430~1436
]-Galactosidase was immobilized in a mixture of k-carrageenan and locust bean gum. The properties of the free and immobilized enzyme were then determined. The optimum pH for both the soluble and immobilized enzyme was 4.8. The optimum temperature for the soluble enzymes was
, whereas that for the immobilized enzyme was
. The immobilized enzyme was used in batch, repeated batch, and continuous modes to degrade the raffinose-family sugars present in soymilk. Two hours of incubation with the free and immobilized
-galactosidases resulted in an 80% and 68% reduction in the raffinose oligo saccharides in the soymilk, respectively. In the repeated batch, a 73% reduction was obtained in the fourth cycle. A fluidized bed reactor was also designed to treat soymilk continuously and the performance of the immobilized
-galactosidase tested at different flow rates, resulting in a 90% reduction of raffinose-family oligosaccharides in the soymilk at a flow rate 40 ml/h. Therefore, the present study demonstrated that immobilized
-galactosidase in a continuous mode is efficient for reducing the oligosaccharides present in soymilk, which may be of considerable interest for industrial application.
Development of Predictive Mathematical Model for the Growth Kinetics of Staphylococcus aureus by Response Surface Model
Seo, Kyo-Young ; Heo, Sun-Kyung ; Lee, Chan ; Chung, Duck-Hwa ; Kim, Min-Gon ; Lee, Kyu-Ho ; Kim, Keun-Sung ; Bahk, Gyung-Jin ; Bae, Dong-Ho ; Kim, Kwang-Yup ; Kim, Cheorl-Ho ; Ha, Sang-Do ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1437~1444
A response surface model was developed for predicting the growth rates of Staphylococcus aureus in tryptic soy broth (TSB) medium as a function of combined effects of temperature, pH, and NaCl. The TSB containing six different concentrations of NaCl (0, 2, 4, 6, 8, and 10%) was adjusted to an initial of six different pH levels (pH 4, 5, 6, 7, 8, 9, and 10) and incubated at 10, 20, 30, and
. In all experimental variables, the primary growth curves were well (
to 0.9975) fitted to a Gompertz equation to obtain growth rates. The secondary response surface model for natural logarithm transformations of growth rates as a function of combined effects of temperature, pH, and NaCl was obtained by SAS's general linear analysis. The predicted growth rates of the S. aureus were generally decreased by basic (pH 9-10) or acidic (pH 5-6) conditions and higher NaCl concentrations. The response surface model was identified as an appropriate secondary model for growth rates on the basis of correlation coefficient (r=0.9703), determination coefficient (
), mean square error (MSE=0.0185), bias factor (
), and accuracy factor (
). Therefore, the developed secondary model proved reliable for predictions of the combined effect of temperature, NaCl, and pH on growth rates for S. aureus in TSB medium.
Flatfish Vitellogenin Detection Using Optical Waveguide Lightmode Spectroscopy-based Immunosensor
Kim, Nam-Soo ; Ryu, Hyung-Seok ; Kim, Woo-Yeon ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1445~1451
A sensitive optical waveguide lightmode spectroscopy-based immunosensor was developed to detect vitellogenin in seawater flatfish (Paralichthys olivaceus). For this purpose, anion-exchange column chromatography with DE-52 resin was used to purify flatfish vitellogenin from flatfish serum containing vitellogenin that had been induced using an intraperitoneal
-estradiol injection. The anti-flatfish vitellogenin antibody used as the biological component of the above immunosensor was prepared using the purified flatfish vitellogenin. The change in the incoupling angle according to the complexation between the flatfish vitellogenin and its antibody, immobilized over an optical grating coupler sensor chip, was measured to calculate the sensor response. The immunosensor was quite specific to flatfish vitellogenin binding, based on no sensor response in the case of bovine serum albumin immobilization. When plotted using double-logarithmic scales, the sensor responses increased linearly in flatfish vitellogenin concentrations of 0.00675-67.5 nM, with a detection limit of 0.0675 nM. The reusability during seven repetitive measurements was reasonably fair for the preliminary screening of flatfish vitellogenin.
Requirement of Fur for the Full Induction of dps Expression in Salmonella enterica Serovar Typhimurium
Yoo, Ah-Young ; Kim, Sam-Woong ; Yu, Jong-Earn ; Kim, Young-Hee ; Cha, Jae-Ho ; Oh, Jeong-Il ; Eo, Seong-Kug ; Lee, John-Hwa ; Kang, Ho-Young ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1452~1459
The Dps protein, which is overexpressed in harsh environments, is known to playa critical role in the protection of DNA against oxidative stresses. In this study, the roles of Fur in the expression of the dps gene in Salmonella and the protection mechanisms against oxidative stress in Salmonella cells preexposed to iron-stress were investigated. Two putative Fur boxes were predicted within the promoter region of the S. typhimurium dps gene. The profile of dps expression performed by the LacZ reporter assay revealed growth-phase dependency regardless of iron-status under the culture conditions. The fur mutant,
, evidenced a reduced level of
-galactosidase as compared to the wild-type strain. The results observed after the measurement of the Dps protein in various Salmonella regulatory mutants were consistent with the results acquired in the reporter assay. This evidence suggested that Fur performs a function as a subsidiary regulator in the expression of dps. The survival ability of Salmonella strains after exposure to oxidative stress demonstrated that the Dps protein performs a pivotal function in the survival of stationary-phase S. typhimurium against oxidative stress. Salmonella cells grown in iron-restricted condition required Dps for full protection against oxidative stress. The CK24 (
) cells grown in iron-replete condition survived at a rate similar to that observed in the wild-type strain, thereby suggesting the induction of an unknown protection mechanism(s) other than Dps in this condition.
Cloning and Characterization of Monofunctional Catalase from Photosynthetic Bacterium Rhodospirillum rubrum S1
Lee, Dong-Heon ; Oh, Duck-Chul ; Oh, You-Sung ; Malinverni, Juliana C. ; Kukor, Jerome J. ; Kahng, Hyung-Yeel ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1460~1468
In this study, an approx. 2.5-kb gene fragment including the catalase gene from Rhodospirillum rubrum S1 was cloned and characterized. The determination of the complete nucleotide sequence revealed that the cloned DNA fragment was organized into three open reading frames, designated as ORF1, catalase, and ORF3 in that order. The catalase gene consisted of 1,455 nucleotides and 484 amino acids, including the initiation and stop codons, and was located 326 bp upstream in the opposite direction of ORF1. The catalase was overproduced in Escherichia coli UM255, a catalase-deficient mutant, and then purified for the biochemical characterization of the enzyme. The purified catalase had an estimated molecular mass of 189 kDa, consisting of four identical subunits of 61 kDa. The enzyme exhibited activity over a broad pH range from pH 5.0 to pH 11.0 and temperature range from
C. The catalase activity was inhibited by 3-amino-1,2,4-triazole, cyanide, azide, and hydroxylamine. The enzyme's
of the catalase for
were 21.8 mM and 39,960 U/mg, respectively. Spectrophotometric analysis revealed that the ratio of
for the catalase was 0.97, indicating the presence of a ferric component. The absorption spectrum of catalase-4 exhibited a Soret band at 406 nm, which is typical of a heme-containing catalase. Treatment of the enzyme with dithionite did not alter the spectral shape and revealed no peroxidase activity. The combined results of the gene sequence and biochemical characterization proved that the catalase cloned from strain S1 in this study was a typical monofunctional catalase, which differed from the other types of catalases found in strain S1.
Purification and Characterization of a New Fibrinolytic Enzyme of Bacillus licheniformis KJ-31, Isolated from Korean Traditional Jeot-gal
Hwang, Kyung-Ju ; Choi, Kyoung-Hwa ; Kim, Myo-Jeong ; Park, Cheon-Seok ; Cha, Jae-Ho ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1469~1476
Jeot-gal is a traditional Korean fermented seafood and has long been used for seasoning. We isolated 188 strains from shrimp, anchovy, and yellow corvina Jeot-gal, and screened sixteen strains that showed strong fibrinolytic activities on a fibrin plate. Among those strains, the strain that had the largest halo zone was chosen and identified as Bacillus licheniformis by using 16S rDNA sequencing and an API CHB kit. The fibrinolytic activity of Bacillus licheniformis was characterized and designated as bpKJ-31. The active component of bpKJ-31 was identified as a 37 kDa protein, designated bacillopeptidase F, by internal peptide mapping and N-terminal sequencing. The optimum activity of bpKJ-31 was shown at pH 9 and
, with a chromogenic substrate for plasmin. It had high degrading activity for the
-chain of fibrin(ogen), and also acted on thrombin, but not skim milk and casein. The amidolytic activity of bpKJ-31 was inhibited by 1 mM phenylmethanesulfonyl fluoride, but 1 mM EDTA did not affect the enzyme activity, indicating that bpKJ-31 is an alkaline serine protease, like a plasmin. The bpKJ-31 showed approximately 14.3% higher fibrinolytic activity than the plasmin. These features of bpKJ-31 make it attractive as a health-promoting biomaterial.
Zinc Metal Solubilization by Gluconacetobacter diazotrophicus and Induction of Pleomorphic Cells
Saravanan, Venkatakrishnan Sivaraj ; Osborne, Jabez ; Madhaiyan, Munusamy ; Mathew, Lazar ; Chung, Jong-Bae ; Ahn, Ki-Sup ; Sa, Tong-Min ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1477~1482
Gluconacetobacter diazotrophicus strain PA15 exhibited a minimum inhibitory concentration value of 11 mM in an LGI medium amended with
. When an LGI medium was amended with Zn metal, solubilization halos were observed in a plate assay, and further solubilization was confirmed in a broth assay. The maximum solubilization was recorded after 120 h with a 0.1% Zn metal amendment. During solubilization, the culture growth and pH of the broth were indirectly correlated. Using a Fourier Transform Infrared Spectroscopy analysis, one of the agents solubilizing the Zn metal was identified as gluconic acid. When the Zn-amended broth was observed under a bright field microscope, long involution cells were observed, and further analysis with Atomic Force Microscopy revealed highly deformed, pleomorphic, aggregate-like cells.
Granulosicoccaceae fam. nov., to Include Granulosicoccus antarcticus gen. nov., sp. nov., a Non-phototrophic, Obligately Aerobic Chemoheterotroph in the Order Chromatiales, Isolated from Antarctic Seawater
Lee, Ki-Young ; Lee, Hong-Kum ; Choi, Tae-Hwan ; Kim, Kyung-Mi ; Cho, Jang-Cheon ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1483~1490
A Gram-negative, motile by tuft flagella, obligately aerobic chemoorganoheterotrophic, sphere-form bacterium, designated
, was isolated from the Antarctic surface seawater of King George Island, West Antarctica. The strain was mesophilic, neutrophilic, and requiring NaCl for growth, but neither halophilic nor halotolerant. The 16S rRNA gene sequence analysis indicated that the strain was most closely related to genera of the order Chromatiales in the class Gammaproteobacteria. The most closely related genera showed less than 90% 16S rRNA gene sequence similarity and included Thioalkalispira (89.9%), Thioalkalivibrio (88.0%-89.5%), Ectothiorhodospira (87.9%-89.3%), Chromatium (88.3%-88.9%), and Lamprocystis (87.7%-88.9%), which represent three different families of the order Chromatiales. Phylogenetic analyses showed that this Antarctic strain represented a distinct phylogenetic lineage in the order Chromatiales and could not be assigned to any of the defined families in the order. Phenotypic characteristics, including primarily non-phototrophic, non-alkaliphilic, non-halophilic, and obligately aerobic chemoheterotrophic properties, differentiated the strain from other related genera. The very low sequence similarities (<90%) and distant relationships between the strain and members of the order suggested that the strain merited classification as a novel genus within a novel family in the order Chromatiales. On the basis of these taxonomic traits, a novel genus and species is proposed, Granulosicoccus antarcticus gen. nov., sp. nov., in a new family Granulosicoccaceae fam. nov. Strain
is the type strain of Granulosicoccus antarcticus.
Anti-inflammatory Effects of Recombinant Arginine Deiminase Originating from Lactococcus lactis ssp. lactis ATCC 7962
Kim, Jong-Eun ; Hur, Haeng-Jeon ; Lee, Ki-Won ; Lee, Hyong-Joo ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1491~1497
Arginine deiminase (ADI, E.C. 18.104.22.168), one of the arginine deprivation enzymes, exhibits anticarcinogenic activities. The present study investigated the anti-inflammatory activities of the purified recombinant ADI originating from Lactococcus lactis ssp. lactis ATCC7962 (LADI). LADI dose-dependently inhibited lipopolysaccharide (LPS)-induced upregulation of inducible nitric oxide synthase and the production of nitric oxide in RAW 264.7 murine macrophages. The induction of cyclooxygenase-2 expression and subsequent production of prostaglandin
by LPS was also attenuated by LADI treatment. Moreover, LADI inhibited the production of interleukin-6 in LPS-stimulated RAW 264.7 macrophages. These results indicate that LADI exerts anti-inflammatory effects, which may in part explain its chemopreventive potential.
Isolation and Characterization of Strain of Bacillus thuringiensis subsp. kenyae Containing Two Novel cry1-Type Toxin Genes
Choi, Jae-Young ; Li, Ming Shun ; Shim, Hee-Jin ; Roh, Jong-Yul ; Woo, Soo-Song ; Jin, Byung-Rae ; Boo, Kyung-Saeng ; Je, Yeon-Ho ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1498~1503
To identify novel crystal proteins, Bacillus thuringiensis 2385-1 was isolated from Korean soil samples and characterized. The H-serotype of 2385-1 was identical to that of subsp. kenyae (H4a4c), and its crystal toxin was bipyramidal-shaped. However, 2385-1 showed a much higher toxicity towards Plutella xylostella and Spodoptera exigua larvae than subsp. kenyae. In addition, the crystal protein profile and plasmid DNA pattern of 2385-1 differed from those of subsp. kenyae. To verify the crystal protein gene types of 2385-1, a PCR-RFLP analysis was performed, and the results revealed that 2385-1 contained two novel cry1-type crystal protein genes, cryl-5 and cry1-12, in addition to the crylJal gene. The deduced amino acid sequences of cryl-5 and cry1-12 showed a 97.9% and 75.7% sequence similarity with the CrylAb and CrylJa crystal proteins, respectively. Among the novel crystal proteins, Cry1-5 showed a high toxicity towards P. xylostella and S. exigua larvae. In conclusion, B. thuringiensis 2385-1 is a new isolate in terms of its gene types, and should be a promising source for an insecticide to control lepidopteran larvae.
Molecular Characterization of FprB (Ferredoxin-
Reductase) in Pseudomonas putida KT2440
Lee, Yun-Ho ; Yeom, Jin-Ki ; Kang, Yoon-Suk ; Kim, Ju-Hyun ; Sung, Jung-Suk ; Jeon, Che-Ok ; Park, Woo-Jun ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1504~1512
The fpr gene, which encodes a ferredoxin-
reductase, is known to participate in the reversible redox reactions between
/NADPH and electron carriers, such as ferredoxin or flavodoxin. The role of Fpr and its regulatory protein, FinR, in Pseudomonas putida KT2440 on the oxidative and osmotic stress responses has already been characterized [Lee at al. (2006). Biochem. Biophys. Res. Commun. 339, 1246-1254]. In the genome of P. putida KT2440, another Fpr homolog (FprB) has a 35.3% amino acid identity with Fpr. The fprB gene was cloned and expressed in Escherichia coli. The diaphorase activity assay was conducted using purified FprB to identify the function of FprB. In contrast to the fpr gene, the induction of fprB was not affected by oxidative stress agents, such as paraquat, menadione,
, and t-butyl hydroperoxide. However, a higher level of fprB induction was observed under osmotic stress. Targeted disruption of fprB by homologous recombination resulted in a growth defect under high osmotic conditions. Recovery of oxidatively damaged aconitase activity was faster for the fprB mutant than for the fpr mutant, yet still slower than that for the wild type. Therefore, these data suggest that the catalytic function of FprB may have evolved to augment the function of Fpr in P. putida KT2440.
Antitumor Effect of Soluble
-1,3-Glucan from Agrobacterium sp. R259 KCTC 1019
Shim, Jung-Hyun ; Sung, Ki-Joong ; Cho, Min-Chul ; Choi, Won-A ; Yang, Young ; Lim, Jong-Seok ; Yoon, Do-Young ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1513~1520
]-1,3-Glucans enhance immune reactions such as antitumor, antibacterial, antiviral, anticoagulatory, and wound healing activities.
-1,3-Glucans have various functions depending on the molecular weight, degree of branching, conformation, water solubility, and intermolecular association. The molecular weight of the soluble glucan was about 15,000 as determined by a high-performance size exclusion chromatography. From the infrared (IR) and
NMR analytical data, the purified soluble glucan was found to exclusively consist of
-D-glucopyranose with 1,3 linkage. We tested the immunestimulating activities of the soluble
-1,3-glucan extracted from Agrobacterium sp. R259 KCTC 1019 and confirmed the following activities. IFN-
and each cytokines were induced in the spleens and thymus of mice treated with soluble
-1,3-glucan. Adjuvant effect was observed on antibody production. Nitric oxide was synthesized in monocytic cell lines treated with
-1,3-glucan. The cytotoxic and antitumor effects were observed on various cancer cell lines and ICR mice. These results strongly suggested that this soluble
-1,3-glucan could be a good candidate for an immune-modulating agent.
Extracellular Secretion of a Maltogenic Amylase from Lactobacillus gasseri ATCC33323 in Lactococcus lactis MG1363 and its Application on the Production of Branched Maltooligosaccharides
Cho, Mee-Hyun ; Park, Sang-Eun ; Lee, Myung-Hun ; Ha, Suk-Jin ; Kim, Hae-Yeong ; Kim, Myo-Jeong ; Lee, Sung-Joon ; Madsen, Soren M. ; Park, Cheon-Seok ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1521~1526
A maltogenic amylase gene from Lactobacillus gasseri ATCC33323 (LGMA) was expressed in Lactococcus lactis MG1363 using the P170 expression system. The successful production of recombinant LGMA (rLGMA) was confirmed by the catalytic activity of the enzyme in liquid and solid media. The N-terminal amino acid sequencing analysis of the rLGMA showed that it was Met-Gln-Leu-Ala-Ala-Leu-, which was the same as that of genuine protein, meaning the signal peptide was efficiently cleaved during secretion to the extracellular milieu. The optimal reaction temperature and pH of rLGMA (
and pH 5, respectively) and enzymatic hydrolysis patterns on various substrates (
-cyclodextrin, starch, and pullulan) supported that rLGMA was not only efficiently secreted from the Lactococcus lactis MG1363 but was also functionally active. Finally, the branched maltooligosaccharides were effectively produced from liquefied com starch, by using rLGMA secreted from Lactococcus lactis, with a yield of 53.1%.
Effects of Ionic Speciation of Lysine on Its Adsorption and Desorption Through a Sulfone-type Ion-Exchange Column
Choi, Dong-Hyouk ; Lee, Ki-Say ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1527~1532
Lysine produced during microbial fermentation is usually recovered by an ion-exchange process, in which lysine is first converted to the cationic form (by lowering the pH to less than 2.0 with sulfuric acid) and then fed to a cationexchange column containing an exchanger that has a sulfone group with a weak counterion such as NH;. Ammonia water with a pH above 11 is then supplied to the column to displace the purified lysine from the column and allow its recovery. To enhance the adsorption capacity and for a possible reduction in chemical consumption, monovalent lysine fed at pH 4 was investigated in comparison with conventional divalent lysine fed at pH 1.5. The adsorption capacity increased by more than 70% on a mass basis using pH 4 feeding compared with pH 1.5 feeding. Lysine adsorbed at pH 4 started to elute earlier than that adsorbed at pH 1.5 when ammonia water was used as the eluant solution, and the extent of early elution became more notable at lower concentrations of ammonia. Moreover, the elution of monovalent lysine fed at pH 4 displayed a stiffer front boundary and higher peak concentration. However, when the ammonium concentration was greater than 2.0 N, complete saturation of the bed was delayed during adsorption and the percent recovery yield from elution was lowered., both drawbacks that were considered inevitable features originating from the increased adsorption of monovalent lysine.
Continuous Production of Lactosucrose by Immobilized Sterigmatomyces elviae Mutant
Lee, Jong-Ho ; Lim, Jung-Soo ; Park, Chul-Hwan ; Kang, Seong-Woo ; Shin, Hyun-Yong ; Park, Seung-Won ; Kim, Seung-Wook ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1533~1537
In this study, in order to develop a continuous production process of lactosucrose in a packed-bed reactor, Sterigmatomyces elviae ATCC 18894 was selected and mutated. The mutant strain of S. elviae showed 54.3% higher lactosucrose production than the wild type. Reaction conditions such as temperature, pH, substrate concentration and flow rate were also optimized. Under optimized reaction conditions (
, pH 6.0, 25% sucrose and 25% lactose as substrate, flow rate 1.2 ml/min), the maximum concentration of lactosucrose (192 g/l) was obtained. In a packed-bed reactor, continuous production of lactosucrose was performed using S. elviae mutant immobilized in calcium alginate, and about 180 g/l of lactosucrose production was achieved for 48 days.
Enhancement of Clavulanic Acid by Replicative and Integrative Expression of ccaR and cas2 in Streptomyces clavuligerus NRRL3585
Hung, Trinh Viet ; Malla, Sailesh ; Park, Byoung-Chul ; Liou, Kwang-Kyoung ; Lee, Hei-Chan ; Sohng, Jae-Kyung ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1538~1545
Clavulanic acid (CA) is an inhibitor of
-lactamase that is produced from Streptomyces clavuligerus NRRL3585 and is used in combination with other antibiotics in clinical treatments. In order to increase the production of CA, the replicative and integrative expressions of ccaR (encoding for a specific regulator of the CA biosynthetic operon) and cas2 (encoding for the rate-limiting enzyme in the CA biosynthetic pathway) were applied. Six recombinant plasmids were designed for this study. The pIBRHL1, pIBRHL3, and pIBRHL13 were constructed for overexpression, whereas pNQ3, pNQ2, and pNQ1 were constructed for chromosomal integration with ccaR, cas2, and ccaR-cas2, respectively. All of these plasmids were transformed into S. clavuligerus NRRL3585. CA production in transformants resulted in a significantly enhanced amount greater than that of the wild type, a 2.25-fold increase with pIBRHLl, a 9.28-fold increase with pNQ3, a 5.06-fold increase with pIBRHL3, a 2.93-fold increase with pNQ2 integration, a 5.79-fold increase with pIBRHLl3, and a 23.8-fold increase with pNQ1. The integrative pNQl strain has been successfully applied to enhance production.
Chemopreventive Effect of Chitosan Oligosaccharide Against Colon Carcinogenesis
Nam, Kyung-Soo ; Kim, Mee-Kyung ; Shon, Yun-Hee ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1546~1549
Chitosan oligosaccharide (COS, 3 kDa
Functional Characteristics of Cyclodextrin Glucanotransferase from Alkalophilic Bacillus sp. BL-31 Highly Specific for Intermolecular Transglycosylation of Bioflavonoids
Go, Young-Hoon ; Kim, Tae-Kwon ; Lee, Kwang-Woo ; Lee, Yong-Hyun ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1550~1553
The functional characteristics of a
-cyclodextrin glucanotransferase (CGTase) excreted from alkalophilic Bacillus sp. BL-31 that is highly specific for the intermolecular transglycosylation of bioflavonoids were investigated. The new
-CGTase showed high specificities for glycosyl acceptor bioflavonoids, including naringin, rutin, and hesperidin, and especially naringin. The transglycosylation of naringin into glycosyl naringin was then carried out under the conditions of 80 units of CGTase per gram of maltodextrin, 5 g/l of naringin, 25 g/l of maltodextrin, and 1 mM
for 6 h, resulting in a high conversion yield of 92.1%.
Antiasthmic Effect of Fermented Artemisia princeps in Asthmic Mice Induced by Ovalbumin
Bae, Eun-Ah ; Min, Sung-Won ; Lee, Bo-Mi ; Kim, Nam-Jae ; Baek, Nam-In ; Han, Eun-Joo ; Chung, Hae-Gon ; Kim, Dong-Hyun ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1554~1557
Artemisia princeps Pampanini (AP) was fermented with Bifidobacterium infantis K-525 and its antiasthmic effect investigated. AP and fennented AP (FAP) reduced the IgE level in the blood of ovalbumin-induced asthmic mice. Moreover, FAP reduced the IgE, proinflammatory cytokine IL-6, and IL-4 levels in the trachea, as well as in the lung of the experimental asthmic mice, whereas AP only reduced the IgE and IL-6 levels in the lungs. Nonetheless, AP and FAP both inhibited the mRNA expression of IL-6 and TNF-
in IgE-induced RBL-2H3 cells. The in vivo antiasthmic effect of FAP was more potent than that of AP. Therefore, these findings suggest that the enhanced antiasthmic effect of AP after bifidus fermentation was possibly due to the regulation of the proinflammatory cytokine biosynthesis of IL-6 and TNF-
Influence of Pipe Materials and VBNC Cells on Culturable Bacteria in a Chlorinated Drinking Water Model System
Lee, Dong-Geun ; Park, Seong-Joo ; Kim, Sang-Jong ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1558~1562
To elucidate the influence of pipe materials on the VBNC (viable but nonculturable) state and bacterial numbers in drinking water, biofilm and effluent from stainless steel, galvanized iron, and polyvinyl chloride pipe wafers were analyzed. Although no HPC (heterotrophic plate count) was detected in the chlorinated influent of the model system, a DVC (direct viable count) still existed in the range between 3- and 4-log cells/ml. Significantly high numbers of HPC and DVC were found both in biofilm and in the effluent of the model system. The pipe material, exposure time, and the season were all relevant to the concentrations of VBNC and HPC bacteria detected. These findings indicate the importance of determining the number of VBNC cells and the type of pipe materials to estimate the HPC concentration in water distribution systems and thus the need of determining a DVC in evaluating disinfection efficiency.
Two Threonine Residues Required for Role of AfsKav in Controlling Morphogenesis and Avermectin Production in Streptomyces avermitilis
Rajkarnikar, Arishma ; Kwon, Hyung-Jin ; Ryu, Yeon-Woo ; Suh, Joo-Won ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1563~1567
AfsKav is a eukaryotic-type serine/threonine protein kinase, required for sporulation and avermectin production in Streptomyces avermitilis. In terms of their ability to complement SJW4001 (
-av), afsK-av mutants T165A and T168A were not functional, whereas mutants T165D and T168D retained their ability, indicating that Thr-165 and Thr-168 are the phosphorylation sites required for the role of AfsKav. Expression of the S-adenosylmethione synthetase gene promoted avermectin production in the wild-type S. avermitilis, yet not in the mutant harboring T168D or T165D, demonstrating that tandem phosphorylation on Thr-165 and Thr-168 in AfsKav is the mechanism modulating avermectin production in response to S-adenosylmethione accumulation in S. avermitilis.
Fumigant Activity of Essential Oils and Components of Illicium verum and Schizonepeta tenuifolia Against Botrytis cinerea and Colletotrichum gloeosporioides
Lee, Sun-Og ; Park, Il-Kwon ; Choi, Gyung-Ja ; Lim, He-Kyoung ; Jang, Kyong-Soo ; Cho, Kwang-Yun ; Shin, Sang-Cheol ; Kim, Jin-Cheol ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1568~1572
To develop a natural fungicide against Botrytis cinerea and Colletotrichum gloeosporioides, a total of 25 essential oils were tested for their fumigant activity against post-harvest pathogens. The vaporous phases of oils were treated to each fungus on potato dextrose agar medium in half-plate separated Petri plates at
per plate. The essential oil of Illicium verum strongly inhibited the mycelial growth of both B. cinerea and C. gloeosporioides by over 90%. On the other hand, the essential oil of Schizonepeta tenuifolia showed inhibitory activity against mycelial growth of only B. cinerea by over 90%. Gas chromatography-mass spectrometry and bioassay indicated trans-anethole in I. verum and menthone in S. tenuifolia as a major antifungal constituent. The essential oils of I. verum and S. tenuifolia and their major constituents could be used to manage post-harvest diseases caused by B. cinerea and C. gloeosporioides.
Cytotoxic Effects of Nanoparticles Assessed In Vitro and In Vivo
Cha, Kyung-Eun ; Myung, Hee-Joon ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1573~1578
An increasing number of applications is being developed for the use of nanoparticles in various fields. We investigated possible toxicities of nanoparticles in cell culture and in mice. Nanoparticles tested were Zn (300 nm), Fe (100 nm), and Si (10-20, 40-50, and 90-110 nm). The cell lines used were brain, liver, stomach, and lung from humans. In the presence of nanopaticles, mitochodrial activity decreased zero to 15%. DNA contents decreased zero to 20%, and glutathione production increased zero to 15%. None of them showed a dose dependency. Plasma membrane permeability was not altered by nanoparticles. In the case of Si, different sizes of the nanoparticles did not affect cytotoxicity. The cytotoxicity was also shown to be similar in the presence of micro-sized (
) Si particles. Organs from mice fed with nanoparticles showed nonspecific hemorrhage, lymphocytic infiltration, and medullary congestion. A treatment with the micro-sized particle showed similar results, suggesting that the acute in vivo toxicity was not altered by nano-sized particles.
5-Aminolevulinic Acid Biosynthesis in Escherichia coli Coexpressing NADP-dependent Malic Enzyme and 5-Aminolevulinate Synthase
Shin, Jeong-Ah ; Kwon, Yeong-Deok ; Kwon, Oh-Hee ; Lee, Heung-Shick ; Kim, Pil ;
Journal of Microbiology and Biotechnology, volume 17, issue 9, 2007, Pages 1579~1584
5-Aminolevulinate (ALA) synthase (E.C. 22.214.171.124), which mediates the pyridoxal phosphate-dependent condensation of glycine and succinyl-CoA, encoded by the Rhodobacter sphaeroides hemA gene, enables Escherichia coli strains to produce ALA at a low level. To study the effect of the enhanced C4 metabolism of E. coli on ALA biosynthesis, NADP-dependent malic enzyme (maeB, E.C. 126.96.36.199) was coexpressed with ALA synthase in E. coli. The concentration of ALA was two times greater in cells coexpressing maeB and hemA than in cells expressing hemA alone under anaerobic conditions with medium containing glucose and glycine. Enhanced ALA synthase activity via coupled expression of hemA and maeB may lead to metabolic engineering of E. coli capable of large-scale ALA production.