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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 13, Issue 6 - Dec 2003
Volume 13, Issue 5 - Oct 2003
Volume 13, Issue 4 - Aug 2003
Volume 13, Issue 3 - Jun 2003
Volume 13, Issue 2 - Apr 2003
Volume 13, Issue 1 - Feb 2003
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Xanthophylls in Microalgae: From Biosynthesis to Biotechnological Mass Production and Application
Jin, Eon-Seon ; Polle, Juergen E.W. ; Lee, Hong-Kum ; Hyun, Sang-Min ; Chang, Man ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 165~174
Xanthophylls are oxygenated carotenoids that serve a variety of functions in photosynthetic organisms and are essential for survival of the organism. Within the last decade, major nor advances have been made in the elucidation of the molecular genetics and biochemistry of the xanthophyll biosynthesis pathway. Microalgae, yeast, or other microorganisms produce some of the xanthophylls that are being commercially used due to their own color and antioxidant properties. Currently, only a few microalgae are being considered or already being exploitd for the production of high-value xanthophylls. However, new developments in molecular biology have important implications for the commercialization of microalgae, and make the genetic manipulation of the xanthophyll content of microalgae mure attractive for biotechnological purposes. Accordingly, the current review summarizes the general properties of xanthophylls in microalgae and the recent developments in the biotechnological production of xanthophylls.
High-Level Production of Astaxanthin by Fed-Batch Culture of Mutant Strain Phaffia rhodozyma AJ-6-1
KIM, SU-JIN ; GEUN-JOONG KIM ; DON-HEE PARK ; YEON-WOO RYU ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 175~181
The production of a carotenoid astaxanthin, a growth-associated principal pigment, is limited in a batch cultivation, because a high glucose concentration severely inhibits the cell growth and also influences the carotenoid production. Therefore, a fermentation strategy including effective chemicals for the high-level production of cells and astaxanthin by a mutant strain Phaffia rhodozyma AJ-6-1 was developed in a fed-batch culture. First, a production medium for maximizing the cell and astaxanthin yields was formulated and optimized. Using this optimized medium, the highest cell and astaxanthin concentrations obtained were about 38.25 g/1 and 34.77 mg/1, respectively. In addition, an attempt was made to increase the amount of astaxanthin using effective chemicals such as ethanol and acetic acid, which are known at an inducer and/or precursor of carotenoid synthesis. When either 10g/1 ethanol or 5 g/1 acetic acid was added to investigate the resulting astaxanthin content, a relatively high astaxanthin concentration or 45.62 mg/l and 43.87 mg/1, respectively, was obtained, and the cell concentrations also increased slightly under these conditions. Therefore, these results imply that a fed-batch culture of the mutant strain P. rhodozyma AJ-6-1 could be effectively employed in the commercial production of astaxanthin, although the factors affecting the productivity remain to be elucidated.
Molecular Structure of PCR Cloned PHA Synthase Genes of Pseudomonas putida KT2440 and Its Utilization for Medium-Chain Length Polyhydroxyalkanoate Production
Kim, Tae-Kwon ; Shin, Hyun-Dong ; Seo, Min-Cheol ; Lee, Jin-Nam ; Lee, Yong-Hyun ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 182~190
A new phaC gene cluster encoding polyhydroxyalkanoate (PHA) synthase I PHA depolymerase, and PHA synthase II was cloned using the touchdown PCR method, from medium-chain length (mcl-) PHA-producing strain Pseudomonas putida KT2440. The molecular structure of the cloned phaCl gene was analyzed, and the phylogenic relationship was compared with other phaCl genes cloned from Pseudomonas species. The cloned phaCl gene was expressed in a recombinant E. coli to the similar level of PHA synthase in the parent strain P. putida KT2440, but no significant amount of mcl-PHA was accumulated. The isolated phaCl gene was re-introduced into the parent strain P. putida KT2440 to amplify the PHA synthase I activity, and the recombinant P. purida accumulated mcl-PHA more effectively, increasing from 26.6 to
. The monomer compositions of 3-hydroxylalkanoates in mcl-PHA were also modified significantly in the recombinant P. putida enforcing the cloned phaCl gene.
In Vitro Glycosylation of Peptide (RKDVY) and RNase A by PNGase F
Park, Su-Jin ; Lee, Ji-Youn ; Park, Tai-Hyun ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 191~195
The in vitro glycosylation of pentapeptide (Arg-Lys-Asp-Val-Tyr; RKDVY) and RNase A was carried out using PNGase F (peptide-N-glycosidase F), and the results were analyzed using MALDI-TOF-MS. Aminated N,N-diretyl chitobiose was used as the sugar in the glycosylation reaction, and the amination yield of N,N'-diacetyl chitobiose was about
. To reduce the water activity and shift the reaction equilibrium to a reverse reaction, 1,4-dioxane or ethylene glycol was used as the organic solvent in the enzymatic glycosylation. A certain extent of nonenzymatic glycosylaton, known as the Maillard reaction, was also observed, which occurs on an arginine or lysine residue when the length of tie sugar residue is one or two. However, the extent of glycosylation was much higher in the enzymatic reaction, indicating that PNGase F can be effectively used to produce glycopeptides and glycoproteins in vitro.
Immune Enhancing Effect by Orally-Administered Mixture of Saccharomyces cerevisiae and Fermented Rice Bran
KOH, JONG HO ; JIN MAN KIM ; HYUNG JOO SUH ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 196~201
The mixture (PM) of Saccharomyces cerevisiae and fermented rice bran on the activation of macrophage and bone marrow cell proliferation was studied in mice. PM stimulated not only the activation of macrophage (1.8-fold of saline) but also IL-6 production from macrophage (1.5-fold) at 2.0 g/㎏/day during 7 days of oral administration. By the culture supernatant of Peyer's patch cells from C3H/HeJ mice fed PM at 2.0 g/㎏/day for 7 days, the bone marrow cells significantly proliferated compared with that of mice receiving only saline (1.7-fold). In addition, the contents of GM-CSF and IL-6 in the culture supernatant of Peyer's patch cells from mice fed PM at 2.0 g/㎏/day were increased in comparison with those from the control (1.8 and 1.4-fold, respectively). These results revealed that oral administration of PM may modulate IL-6 production to induce the activation of macrophage, and also enhance secretion of hematopoietic growth factors such as GM-CSF and IL-6 from Peyer's patch cells.
In Vitro Immunopotentiating Activity of Cellular Components of Lactococcus lactis ssp. lactis
Kim, Ji Yeon ; Lee, Seong-Kyu ; Ciiimura, Satoshi-Ha ; Kaminogawa, Shuichi ; Lee, Hyong-Joo ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 202~206
To determine the effect of immunopotentiating activity of cellular components of Lactococcus lactis ssp. lactis, the immune function was analyzed in vitro using mice cells. When stimulated with mitogens, productions of
, and IL-6 were enhanced in spleen cells treated with cellular components, with IL-4 production being the highest in spleen cells treated with cytoplasm fraction. Without mitogen stimulation, the productions of
and IL-12 were the highest in spleen cells treated with heat-killed whole cell.
and IL-6 productions were also high in spleen cells treated with all cellular components. Only heat-killed whole cell showed significant enhancement in natural killer cell activity. In peritoneal exudates cells,
production was enhanced significantly by all cellular components of Lactococcus lactis ssp. lactis These results indicate that the cellular components of Lactococcus lactis ssp. lactis are capable of stimulating immune cells to produce cytokines, and that both their cell walls and cytoplasm fraction contribute to these capacities.
Isolation and Identification of a Lactic Acid Bacterial Strain KJ-108 and Its Capability for Deodorizing Malodorous Gases Under Anaerobic Culture Conditions
KIM, JEONG-DONG ; JUNG-HOON YOON ; YONG-HA PARK ; DAE-WEON LEE ; KYOU-SEUNG LEE ; CHANG-HYUN CHOI ; WON-YEOP PARK ; KOOK-HEE KANG ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 207~216
A number of different sources, such as composts, leachates, and pig feces samples, were collected from different pig farms in Korea, and several microorganisms were screened for their ability to deodorize the malodorous gases. Consequently, a novel malodorous gases-deodorizing bacterial strain, KJ-108. was isolated, because it was highly abundant in nitrate-supplemented minimal medium (
) under anaerobic culture conditions. Airtight crimp-sealed serum bottles containing
, medium were inoculated with KJ-108. Nitrate concentration was decreased rapidly after 20 h of incubation, and incubation was carried out until nitrite production reached almost zero. Taxonomic identification, including 16S rDNA base sequencing and phylogenetic analysis, indicated that the isolate had
homology in its 165 rDNA base sequence with Lactobacillus pentosus. Among the volatile fatty acids, acetic acid contained in large amounts in fresh piggery slurry was decreased by about
after 50 h incubation with strain KJ-108. n-Butyric acid, n-valeric acid, and isovaleric acid were gradually decreased, and isobutyric acid and capronic acid were dramatically eliminated at theinitial period with the treatment. Moreover, NH, removal efficiency reached a maximum of
after 50 h of incubation, but the concentration of
was not changed.
Reduction of Ammonia Accumulation and Improvement of Cell Viability by Expression of Urea Cycle Enzymes in Chinese Hamster Ovary Cells
Chung, Myung-Il ; Lim, Mi-Hee ; Lee, Yun-Jeong ; Kim, Ik-Hwan ; Kim, Ick-Young ; Kim, Jung-Hoe ; Chang, Kern-Hee ; Kim, Hong-Jin ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 217~224
Previously, we developed a CHO cell line (CHO-OTC1-Al9) that expresses the first two enzymes in the urea cycle and exhibits a higher ammonia-removing ability and faster growth rate than a vector-controlled CHO cell line (CHO-neo-5). The current study was undertaken to develop a cell line with an ammonia-removing ability higher than the cell line developed previously. To accomplish this, CHO cell lines expressing the first three, first four, or all five enzymes of the urea cycle were constructed using a stable transfection method. Finally, the CHO-AS-16, CHO-AL-19, and CHO-Arg-11 cell lines expressing the first three, first four, and all five enzymes of the urea cycle, respectively, were selected and found to exhibit higher ammonia-removing ability than the CHO-OTC1-Al9 cell line. Among the three selected cell lines, CHO-AL-19 showed the highest ammonia-removing ability and highest cell viability at a higher cell density, with 40% and 15% lower ammonia concentration in the, culture media than that of CHO-neo-5 and CHO-OTC1-A19 cell lines, respectively. CHO-AL-19 also showed 44% and 10% higher cell viability than the CHO-neo-5 and CHO-OTC-Al9 cell lines, at a higher cell density, respectively. The ammonia concentrations in the culture media were expressed as the ammonia concentration/cell, and the CHO-AL-19 cells revealed 45-60% and 20% lower ammonia concentration/cell than the CHO-neo-5 and CHO-OTC1-Al9 cells, respectively.
The Membrane-Bound NADH:Ubiquinone Oxidoreductase in the Aerobic Respiratory Chain of Marine Bacterium Pseudomonas nautica
Lee, Young-Jae ; Cho, Kyeung-Hee ; Kim, Young-Jae ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 225~229
Each oxidoreductase activity of the aerobic respiratory chain-linked NADH oxidase system in the marine bacterium Pseudomonas nautica was stimulated by monovalent cations including
. In the presence of NADH or deamino-NADH as electron donors,
formation was approximately 1.3-fold higher in the presense of 0.08 M of
, Whereas the other reductase activities were not significantly higher in
. The optimal pH of NADH (or deamino-NADH):ubiquinone-1 oxidoreductase was 9.0 in the presence of 0.08 M NaCl. The activity of NADH (or deamino-NADH):ubiquinone-1 oxidoreductase was inhibited by about 33% with
2-heptyl-4-hydroxyquinoline-N-oxide (HQNO). The activity of NADH (deamino-NADH): ubiquinone-1 oxidoreductase was inhibited by about 32 to 38% with
rotenone, whereas the activity was highly resistant to capsaicin. On the other hand, electron transfer from NADH or deamino-NADH to ubiquinone-1 generated a membrane potential (
) which was larger in the presence of
than that observed in the absence of
was almost completely collapsed by
carbonylcyanide m-chlorophenylhydrazone(CCCP), and approximately 50% inhibited by
2-heptyl-4-hydroxyquinoline (HQNO). Also, HQNO made the
very unstable. The results suggest that the enzymatic and energetic properties of the NADH:ubiquinone oxidoreductase of P. nautica are quite different, compared with those of other marine halophilic bacteria.
Enzymatic Characterization of a Recombinant Levansucrase from Rahnella aquatilis ATCC 15552
Kim, Hyun-Jin ; Park, Hae-Eun ; Kim, Min-Jeong ; Lee, Hyeon-Gyu ; Yang, Ji-Young ; Cha, Jae-Ho ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 230~235
A 1.25 kb DNA fragment including the lscR gene, which encodes a levansucrase of Rahnella aquatilis ATCC 15552, was subcloned into a high-expression vector, pET-29b, and the recombinant enzyme was overexpressed in Escherichia coli. Most of the levansucrase activity was detected in the cytoplasmic fraction after induction with isopropyl
. The recombinant enzyme with a tag of six histidine residues at the C-terminus was purified 146-fold by affinity and gel-filtration chromatographies. The molecular mass of the purified LscR was approx. 49 kDa as determined by SDS-PAGE. The optimum pH and temperature of this enzyme for levan formation was pH 6.0 and
, respectively. The optimum substrate concentration for levan formation was 300 mM sucrose. Levan formation was increased by the increase of the enzyme concentrations. Maxium yield of levan formation at optimum substrate concentration, pH, and temperature after 24 h of reaction was approximately 80%.
Analysis of Bacterial Community Structure in Bulk Soil, Rhizosphere Soil, and Root Samples of Hot Pepper Plants Using FAME and 16S rDNA Clone Libraries
Kim, Jong-Shik ; Kwon, Soon-Wo ; Jordan, Fiona ; Ryu, Jin-Chang ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 236~242
A culture-independent and -dependent survey of the bacterial community structure in the rhizosphere and soil samples from hot pepper plants was conducted using 16S rDNA clone library and FAME analyses. Out of the 78 clones sequenced, 56% belonged to Proteobacteria, 4% to high G+C Gram- positive group, 3% to Cytophyga-Flexibacter-Bacreroides, and 32% could not be grouped with any known taxonomic division. Among the 127 FAME isolates identified, 66% belonged to low G+C Gram-positive bacteria (Baciilus spp.) and 26% to high G+C Gram-positive bacteria. In a cluster analysis, the results for both methods were found to be strikingly dissimilar. The current study is the first comparative study of FAME and 165 rDNA clonal analyses performed on the same set of soil, rhizosphere soil, and root samples.
Isolation and Characterization of 4-(2,4-Dichlorophenoxy)Butyric Acid-Degrading Bacteria from Agricultural Soils
Park, In-Hyun ; Ka, Jong-Ok ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 243~250
Eight numerically dominant 4-(2,4-dichlorophenoxy) butyric acid (2,4-DB)-degrading bacteria and three pairs of bacteria showing syntrophic metabolism of 2,4-DB were isolated from soils, and their phylogenetic and phenotypic characteristics were investigated. The isolates were able to utilize 2,4-DB as a sole source of carbon and energy, and their 2.4-DB degradative enzymes were induced by the presence of 2.4-DB. Analysis of 16S rDNA sequences indicated that the isolates were related to members of the genera, Variovorax, Sphingomonas, Bradyrhizobium, and Pseudomonas. The chromosomal DNA patterns of the isolates obtained by polymerase-chain-reaction (PCR) amplification of repetitive extragenic palindromic (REP) sequences were distinct from each other. Four of the isolates had plasmids, but only one strain, DB 1, rad a transmissible 2,4-D degradative plasmid. When analyzed with PCR using primers targeted to the tfdA, B, and C genes, only strains DB2 and DB9a produced DNA bands of the expected sizes with the tfdA and C primers, respectively. All of the isolates were able to degrade 2,4-D as well as 2,4-DB, suggesting that the degradation pathways of these compounds were closely related to each other, but respiratory activities of many isolates adapted to 2,4-DB metabolism were quite low with 2,4-D.
Bacterial Community Variations in Hot Pepper-Sown Soil Using FAME Analysis as an Indicator of Soil Quality
Kim, Jong-Shik ; Weon, Hang-Yeon ; Kwon, Soon-Wo ; Ryu, Jin-Chang ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 251~255
The bacterial compositions of seven hot-pepper sown soil were compared in this study. From the 624 isolates, 95 species and 49 genera were identified by fatty acid methyl ester analysis (FAME). The FAME results of seven soil showed two distinct clusters for aerobic and Gram-negative bacteria in the high productivity and monoculture soil samples. While Arthrobacter (
), Kocuria (
), Pseudomonas (
), and Bacillus (
) were predominant among bacteria which were cultured on heterotrophic (YG) agar medium, Pseudomonas (
), Stenotrophomonas (
), and Burkholderia (
) were predominant on crystal violet agar medium. Shannon Weaver indices (H) indicated that colonies obtained from heterotrophic agar medium (3.1) were found to be more diverse than those obtained from the crystal violet media (1.9). The results suggest that FAME analysis may be a potential indicator for of soil quality.
Effects of Growth Regulators and Organic Nitrogen Sources on the Production of Heavy Chain Immunoglobulin G in Suspension Cultures of Transgenic Tobacco Cells
Shin, Joong-Han ; Kim, Kyoung-Heon ; Kim, Tae-Hwan ; Lee, James M. ; Lee, Hyong-Joo ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 256~262
To enhance the production of heavy chain immunoglobulin G (HC IgG) in the suspension cultures of transgenic tobacco cells (Nicotiana tabacum), the effects of adding various cytokinins (i.e., growth regulators) and organic nitrogen sources to culture media were investigated. Four different cytokinins including kinetin, isopentenyladenine (IPA), 6-benzylaminepurine (BA), and zeatin were tested with or without dichlorophenoxyacetic acid (2,4-D), which is a typical growth regulator supplemented in the standard Murashige and Skoog (MS) medium. The productivity of intracellular HC IgG was increased by 36 and
, compared to the control, especially when IPA (2 mg/l) or BA (0.2 mg/l) was added to the media in the presence of 2,4-D, respectively. In the study of organic nitrogen sources, addition of each casein hydrolysate and tryptone to the culture media at a final concentration of 0.01 and 1 g/l, respectively. increased the productivity or he IgG as much as 68 and
, respectively, in comparison with the control, which was is MS medium without supplementation of any organic nitrogen sources. This study shows that the optimization of media composition could offer significant improvements in the production of foreign proteins in the suspension cultures of transgenic plants.
Interacting Domain Between Yeast Chitin Synthase 3 and Chitin Synthase 4 is Involved in Biogenesis of Chitin Ring, but not for Cell Wall Chitin
Choi, Shin-Jung ; Park, Nok-Hyun ; Park, Hyun-Sook ; Park, Mee-Hyun ; Woo, Jee-Eun ; Choi, Won-Ja ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 263~268
Recently, we identified a domain, termed MIRC3-4, for the protein-protein interaction between yeast chitin synthase 3 (CHS3) and chitin synthase 4 (CHS4). In this study, the functional roles of MIRC3-4 were examined at the G1 phase and cytokinesis of the cell cycle by Calcofluor staining and FISH. Some mutations in MIRC3-4 resulted in disappearance of the chitin ring in the early G1 phase, but did not affect chitin synthesis in the cell wall at cytokinesis. The chitin distribution in chs4 mutant cells indicated that CHS4 was involved in the synthesis of chitinring in the G1 phase and in the synthesis of cell wall chitin after cytokinesis, suggesting that Chs4p regulates chitin synthase 3 activity differently in G1 and cytokinesis. Absence of the chitin ring could be caused either by delocalization of Chs3p to the bud-neck or by improper interaction with Chs4p. When mutant cells were immunostained with a Chs3p-specific antibody to discriminate between these two alternatives, the mutated Ch3p was found to localize to the neck in all MIRC3-4 mutants. These results strongly irdicate that Chs4p regulates Chs3p as an activator but not a recruiter.
Purification and Characterization of the
from Aspergillus flavus IAM2044
Ji, Jae-Hoon ; Yang, Ju-Seok ; Hur, Jong-Wha ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 269~275
Chitosan-degrading activity induced by chitosan was founf in culture filtrate of Aspergillus flavus IAM2044. Aspergillus flavus IAM2044 had a higher level of chitosanolytic activity when chitosan was used as a carbon source, and yeast extract and peptone were supplemented as nitrogen sources. One of the chitosan-degrading enzymes was purified to homogeneity by ammonium sulfate precipitation followed by cation-exchange and gel filtration chromatographies. The enzyme was monomeric, and its molecular mass was 45 kDa. The optimum pH and temperature of the enzyme were 5.0 and
, respectively. The activity was stable in the pH range of 3.5 to 7.0 and at a temperature below
. Reaction products analyzed by the viscosimetric assay and thin layer chromatography clearly indicated that the enzyme was an exe-type chitosanase,
, that released GlcN from the nonreducing ends of the oligosaccharide chains.
Characterization of Adhesion of Bifidobacterium sp. BGN4 to Human Enterocyte-Like Caco-2 Cells
Kim, In-Hee ; Park, Myung-Soo ; Ji, Geun-Eog ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 276~281
The adhesion of probiotic bacteria to the intestinal mucosa is one of the desirable properties for their colonization in the intestinal tract, where these bacteria constantly compete with other bacteria. The adhesion of different strains of bifidobacteria to Caco-2 cells was compared. Among the strains examined, BGN-4 showed the highest adhesion level and the greatest cell surface hydrophobicity (CSH). No close relationship was found between the adhesion and CSH of the strains. Upon protease and heat treatment, the adhesion of the BGN-4 to the Caco-2 cells decreased significantly. The cells grown at
showed a lower CSH and self-aggregation levels than cells grown at
. The treatment of EGTA did not have any effect on the adhesion. The degree of adhesion did not differ among the experimental groups in which galactose, mannose, or fucose were added in the adhesion assay mixture. The results suggest that the adhesion of the Bifidobacterium to the epithelial cells may be affected by the composition and structure of the cell membrane and interacting surfaces.
Cloning of a Potentially Strain-Specific DNA Probe of prevotella intermedia ATCC 25611 by Inverted Dot Blot Hybridization Screening Method
Kook, Joong-Ki ; Han, Jin-Ju ; Kim, Hwa-Sook ; Seong, Jin-Hyo ; Kim, Dong-Kie ; Baek, Dong-Heon ; Choe, Son-Jin ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 282~286
The purpose of this study was to isolate a specific DNA probe for the strain ATTC 25611 of the species Prevotella intermedia by using a new rapid screening mothod. The whole-genomic DNA of P. intermedia ATCC 25611 was isolated and purified. The HindIII-digested genomic DNAs from the strain were cloned by the random cloning method. To screen the strain-specific DNA probe, inverted dot blot hybridization tests were performed. In this assay, 20 ng of recombinant plasmids containing the HindIII-digested genomic DNA fragment were boiled and blotted onto a nylon membrane, and hybridized with digoxigenin-dUTP labeled genomic DNAs in a concentration of 100 ng/ml. Southern blot analysis was performed in order to confirm the results of the inverted dot blot hybridization tests. The data showed that a Pi34 probe (2.1 kbp; 1 out of 32 probes) was specific for P. intermedia strain ATCC 25611 and could be useful for the detection and identification of the strain, particularly in epidemiological studies of periodontal disease.
Effects of Minor Arginyl tRNA and Isoleucyl tRNA on the Expression of Clostridium botulinum Neurotoxin Light Chain in Escherichia coli
Kim, Jin-Sook ; Seong, Hye-Young ; Kim, Mi-Wha ; Ku, Jong-Seo ; Choi, Soon-Yong ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 287~291
Botulinum neurotoxin type A (BONT/A) is an extremely potent toxin, which is produced by Clostridium botulinum. The light chain of this protein (BONT/A LC), which is known as a zinc endopeptidase, cleaves SNAP-25 involved in the exocytosis process. In this work, the expression of recombinant BoNT/A LC in E. coli is described. The BONT/A LC gene of C. botulinum contains a high frequency of the arginine AGA and isoleucine ATA codons that are rarely used in genes of E. coli, hampering the translation of recombinant protein. The argD and ilex tRNA genes were cloned into pACYC184 vector, resulting in pAAD131X plasmid. The translational stress of the toxin gene related to codon bias was reversed by fupplernentation of the AGA arginyl tRNA of T4 phage and AUA isoleucyl tRNA of E. coli. This system may be applicable for the expression of a variety of AT-rich heterologous genes in E. coli.
Identification of Genes for Biosynthesis of Antibacterial Compound from Pseudomonas fluorescens Bl6, and Its Activity Against Ralstonia solanacearum
Kim, Jin-Woo ; Kim, Jung-Gun ; Park, Byoung-Keun ; Choi, Ok-Hee ; Park, Chang-Seuk ; Hwang, In-Gyu ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 292~300
Pseudomonas fluorescens B16 is a plant glowth-prornoting rhizobacterium, which produces an antibacterial compound that is effective against plant root pathogens, such as Agrobacrerium tumefaciens and Raistonia solanacearum. We mutagenized the strain B16 with Omegon-Km and isolated six antibacterial-activity-deficient mutants. Two cosmid clones that hybridized with the mutant clones also were isolated from a genomic library of tile parent strain. Using deletion and complementation analyses, it was found that the biosynthesis genes resided in a 4.3-kb SalI-NarI fragment. When a plasmid clone carrying the fragment was introduced into P. fluorescens strain 1855.344, which does not exhibit any antibacterial activity, the transconjugants exhibited antibacterial activity, indicating that the plasmid clone carried all the genes essential for production of the antibacterial compound. DNA sequence analysis of the fragment identified four putative open reading frames (ORFs): orf1 through orf4 The deduced amino acid sequences of ORF1, ORF2, and ORF4 were similar to cystathionine gamma lyase, pyruvate formate-lyase activating enzyme, and transcriptional regulator, respectively, yet the amino acid sequence of ORF3 showed no similarities to any known proteins. It was also demonstrated that the antibacterial activity was responsible for biological control of the bacterial wilt caused by R. solanacearum.
Removal of Hydrogen Sulfide, Ammonia, and Benzene by Fluidized Bed Reactor and Biofilter
Kim, Chong-Woo ; Park, Jin-Su ; Cho, Sung-Ki ; Oh, Kwang-Joong ; Kim, Young-Sik ; Kim, Dong-Uk ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 301~304
In this study, hydrogen sulfide (
), ammonia (
), and benzene, which represent the major odor from a natural leather process plant, were removed using a fluidized bed bioreactor and biofilter including Thiobacillus sp. IW and a MY microbial consortium. The critical removal rate was
for benzene by the fluidized bed bioreactor, and
for benzene in the biofilter. The average removal efficiency of
, and benzene by continuous operation for over 30 days with the fluidized bed bioreactor was
, respectively, whereas that with the biofilter was
, respectively. Therefore, the critical removal rate of
, and benzene was higher in the fluidized bed bioreactor, whereas the removal efficiency on the continuous operation was similar in both bioreactors.
Constructions of bft-k and t-3 Deficient Mutants of Bacteroides fragilis: Possible Role for Metalloprotease in Pathogenesis
Lee, Gun-Young ; Rhie, Gi-Eun ; Chung, Gyung-Tae ; Sung, Won-Keun ; Oh, Hee-Bok ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 305~308
We earlier reported the identification of bif-k, t-3, and a third ORF from an enterotoxigenic strain of Bacteroides fragilis 419, which was isolated from the blood of a Korean patient suffering from systemic infections. In the present study, the deleted fragments of the t-3 and the bft-k genes from B. fragilis 419 were cloned into suicide vector PJST55 and used to create a mutant with chromosomal disruption of the t-3 and bft-k genes. Structures of the selected mutants, DMP-2 and DBT-4, were found to be intermediate forms that integrated the suicide vector into the chromosome. t-3 disrupted Dmp-2 and Bft-k disrupted DBT-4 did not react with polyclonal antibodies against T-3 or BFT-K, and had no biological activity in
Characteristics of Nitrobenzene Degradation by Mycobacterium chelonae Strain NB01
Oh, Young-Sook ; Lee, Youn-Hee ; Lee, Jung-Hyun ; Choi, Sung-Chan ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 309~312
A bacterial strain NB01, isolated from wastewater, was found to utilize nitrobenzene (NB) as the sole source of nitrogen, carbon, and energy. The strain was classified as a member of a high G+C Gram-positive group and identified as Mycobacterium chelonae based on an analysis of its 16S rRNA gene sequence. The strain grew on NB with a concomitant release of about 63% of the total available nitrogen as ammonia, suggesting a reductive degradation mechanism. The optimal pH and temperature for degradation were PH 7.0-8.0 and
, respectively. The cell growth was retarded at NB concentrations above 1.8 mM. The degradation of NB followed Michaelis-Menten kinetics within the tolerance range, and the
and maximum specific removal rate for NB were 0.33 mM and
Demonstration of Two Independent Dextranase and Amylase Active Sites on a Single Enzyme Elaborated by Lipomyces starkeyi KSM 22
LEE, SO-YOUNG ; JIN-HA LEE ; JOHN F. ROBYT ; EUN-SEONG SEO ; HYEN-JOUNG PARK ; DOMAN KIM ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 313~316
Lipomyces starkeyi KSM 22 elaborates an enzyme that has both dextranase and amylase activities in a single protein of 100 kDa. Competition studies, using different amounts of dextran and starch as substrates, gave a competition plot consistent with the hypothesis that the hydrolysis of dextran and starch occurs at two independent active sites, each specific for starch and dextran, respectively.
Drug-Induced Haploinsufficiency of Fission Yeast Provides a Powerful Tool for Identification of Drug Targets
PARK, JO-YOUNG ; YOUNG-JOO JANG ; SEOG-JONG YOU ; YOUNG-SOOK KIL ; EUN-JUNG KANG ; JEE-HEE AHN ; YOUNG-KWON RYOO ; MIN-YOUN LEE ; MISUN WON ;
Journal of Microbiology and Biotechnology, volume 13, issue 2, 2003, Pages 317~320
Genome-wide systematic deletion mutants were generated using a PCR-based targeted mutagenesis of Schizosacchaaromyces pombe. In a drug-sensitivity assay using thiabendazole(TBZ), an inhibitor of microtubule assembly, a heterozygous nda2 mutant (
), deleting one copy of nda2 encoding the microtubule subunit alpha1 demonstrated a distinct sensitivity to TBZ, indicating TBZ-induced haploinsufficiency. This result suggests that profiling drug-induced haploinsufficiency can be exploited to identify target genes for drugs and discover new drugs.